Smack 4.5.0-alpha2-SNAPSHOT

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Merge tag '4.4.5'

Smack 4.4.5

NOTICE

@@ -29,6 +29,7 @@ Chris Deering
 Christoph Fiehe
 Craig Hesling
 Damian Minkov
+Dan Caseley
 Daniele Ricci
 Daniel Henninger
 Daniel Hintze
@@ -44,6 +45,7 @@ Fernando Ramirez
 Florian Kimmann
 Florian Schmaus
 Francisco Vives
+Frank Matheron
 Gaston Dombiak
 Georg Lukas
 Gilles Cornu
@@ -64,6 +66,7 @@ Jay Kline
 Jeff Williams
 Jesus Fuentes
 John Haubrich
+Jonathan Lennox
 Júlio Cesar Bueno Cotta
 Lars Noschinski
 Luca Stucchi
@@ -82,6 +85,7 @@ Pete Matern
 Piotr Nosek
 Rajat Kumar Gupta
 Robin Collier
+Simon Abykov
 Simon Schuster
 Son Goku
 Tairs Rzajevs

build.gradle

@@ -6,6 +6,7 @@ buildscript {
     }
     dependencies {
 		classpath 'org.kordamp.gradle:clirr-gradle-plugin:0.2.2'
+		classpath "biz.aQute.bnd:biz.aQute.bnd.gradle:6.0.0"
     }
 }
 
@@ -147,7 +148,7 @@ allprojects {
 		smackMinAndroidSdk = 19
 		junitVersion = '5.7.1'
 		commonsIoVersion = '2.6'
-		bouncyCastleVersion = '1.68'
+		bouncyCastleVersion = '1.69'
 		guavaVersion = '30.1-jre'
 		mockitoVersion = '3.7.7'
 		orgReflectionsVersion = '0.9.11'
@@ -196,10 +197,6 @@ allprojects {
 	repositories {
 		mavenLocal()
 		mavenCentral()
-		// Add OSS Sonatype Snapshot repository
-		maven {
-			url 'https://oss.sonatype.org/content/repositories/snapshots'
-		}
 	}
 
 	tasks.withType(JavaCompile) {
@@ -450,6 +447,7 @@ subprojects {
 	apply plugin: 'signing'
 	apply plugin: 'checkstyle'
 	apply plugin: 'org.kordamp.gradle.clirr'
+	apply plugin: 'biz.aQute.bnd.builder'
 
 	checkstyle {
 		toolVersion = '8.27'
@@ -615,6 +613,12 @@ subprojects*.jar {
 	manifest {
 		from sharedManifest
 	}
+	bundle {
+		bnd(
+				'-removeheaders': 'Tool, Bnd-*',
+				'-exportcontents': '*',
+		)
+	}
 }
 
 configure(subprojects - gplLicensedProjects) {

documentation/developer/integrationtest.md

@@ -86,6 +86,27 @@ debugger=console
 
 The framework will first load the properties file from `~/.config/smack-integration-test/properties`
 
+### Running selected tests only
+
+Using `enabledTests` is is possible to run only selected tests. The
+tests can be selected on a per class base or by specifying concrete
+test methods. In the latter case, the methods must be qualified by a
+(simple) class name.
+
+For example:
+
+```bash
+$ gradle integrationTest -Dsinttest.enabledTests=SoftwareInfoIntegrationTest.test
+```
+
+will only run the `test()` method of `SoftwareInfoIntegrationTest`, whereas
+
+```bash
+$ gradle integrationTest -Dsinttest.enabledTests=SoftwareInfoIntegrationTest
+```
+
+would run all tests defined in the `SoftwareInfoIntegrationTest` class.
+
 Overview of the components
 --------------------------
 

resources/generate-notice-file

@@ -0,0 +1,38 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+SCRIPT_DIR="$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )"
+SMACK_DIR=$(realpath "${SCRIPT_DIR}/..")
+
+cd "${SMACK_DIR}"
+
+TEMPFILE=$(mktemp)
+
+cleanup() {
+	rm "${TEMPFILE}"
+}
+trap cleanup EXIT
+
+git shortlog -s |\
+	cut -f2- |\
+	grep -v '(no author)' |\
+	grep '\w \w.*' |\
+	sort \
+	> "${TEMPFILE}"
+
+readonly NOTICE_FILE="${SMACK_DIR}/NOTICE"
+
+cat <<EOF > "${NOTICE_FILE}"
+                 Smack
+
+       An open-source XMPP library
+      maintained by Florian Schmaus
+
+ https://igniterealtime.org/projects/smack
+
+
+Authors:
+
+EOF
+
+cat "${TEMPFILE}" >> "${NOTICE_FILE}"

resources/get-contributors.sh

@@ -1,7 +0,0 @@
-#!/usr/bin/env bash
-
-git shortlog -s |\
-	cut -f2- |\
-	grep -v '(no author)' |\
-	grep '\w \w.*' |\
-	sort

smack-bosh/src/main/java/org/jivesoftware/smack/bosh/XMPPBOSHConnection.java

@@ -43,6 +43,7 @@ import org.jivesoftware.smack.packet.StanzaError;
 import org.jivesoftware.smack.util.CloseableUtil;
 import org.jivesoftware.smack.util.PacketParserUtils;
 import org.jivesoftware.smack.xml.XmlPullParser;
+import org.jivesoftware.smack.xml.XmlPullParserException;
 
 import org.igniterealtime.jbosh.AbstractBody;
 import org.igniterealtime.jbosh.BOSHClient;
@@ -200,6 +201,14 @@ public class XMPPBOSHConnection extends AbstractXMPPConnection {
                     + getHost() + ":" + getPort() + ".";
             throw new SmackException.SmackMessageException(errorMessage);
         }
+
+        try {
+            XmlPullParser parser = PacketParserUtils.getParserFor(
+                            "<stream:stream xmlns='jabber:client' xmlns:stream='http://etherx.jabber.org/streams'/>");
+            onStreamOpen(parser);
+        } catch (XmlPullParserException | IOException e) {
+            throw new AssertionError("Failed to setup stream environment", e);
+        }
     }
 
     @Override
@@ -511,7 +520,7 @@ public class XMPPBOSHConnection extends AbstractXMPPConnection {
                                 parseAndProcessStanza(parser);
                                 break;
                             case "features":
-                                parseFeatures(parser);
+                                parseFeaturesAndNotify(parser);
                                 break;
                             case "error":
                                 // Some BOSH error isn't stream error.

smack-core/build.gradle

@@ -1,3 +1,8 @@
+// Note that this is also declared in the main build.gradle for
+// subprojects, but since evaluationDependsOnChildren is enabled we
+// need to declare it here too to have bundle{bnd{...}} available
+apply plugin: 'biz.aQute.bnd.builder'
+
 description = """\
 Smack core components."""
 
@@ -55,3 +60,11 @@ task createVersionResource(type: CreateFileTask) {
 }
 
 compileJava.dependsOn(createVersionResource)
+
+jar {
+	bundle {
+		bnd(
+				'DynamicImport-Package': '*',
+		)
+	}
+}

smack-core/src/main/java/org/jivesoftware/smack/AbstractXMPPConnection.java

@@ -524,9 +524,6 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
         closingStreamReceived = false;
         streamId = null;
 
-        // The connection should not be connected nor marked as such prior calling connectInternal().
-        assert !connected;
-
         try {
             // Perform the actual connection to the XMPP service
             connectInternal();

smack-core/src/main/java/org/jivesoftware/smack/ConnectionConfiguration.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2003-2007 Jive Software, 2017-2020 Florian Schmaus.
+ * Copyright 2003-2007 Jive Software, 2017-2022 Florian Schmaus.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -32,6 +32,7 @@ import java.security.KeyStoreException;
 import java.security.NoSuchAlgorithmException;
 import java.security.NoSuchProviderException;
 import java.security.Provider;
+import java.security.SecureRandom;
 import java.security.Security;
 import java.security.UnrecoverableKeyException;
 import java.security.cert.CertificateException;
@@ -189,7 +190,7 @@ public abstract class ConnectionConfiguration {
     protected ConnectionConfiguration(Builder<?, ?> builder) {
         try {
             smackTlsContext = getSmackTlsContext(builder.dnssecMode, builder.sslContextFactory,
-                            builder.customX509TrustManager, builder.keystoreType, builder.keystorePath,
+                            builder.customX509TrustManager, builder.keyManagers, builder.sslContextSecureRandom, builder.keystoreType, builder.keystorePath,
                             builder.callbackHandler, builder.pkcs11Library);
         } catch (UnrecoverableKeyException | KeyManagementException | NoSuchAlgorithmException | CertificateException
                         | KeyStoreException | NoSuchProviderException | IOException | NoSuchMethodException
@@ -252,7 +253,7 @@ public abstract class ConnectionConfiguration {
     }
 
     private static SmackTlsContext getSmackTlsContext(DnssecMode dnssecMode, SslContextFactory sslContextFactory,
-                    X509TrustManager trustManager, String keystoreType, String keystorePath,
+                    X509TrustManager trustManager, KeyManager[] keyManagers, SecureRandom secureRandom, String keystoreType, String keystorePath,
                     CallbackHandler callbackHandler, String pkcs11Library) throws NoSuchAlgorithmException,
                     CertificateException, IOException, KeyStoreException, NoSuchProviderException,
                     UnrecoverableKeyException, KeyManagementException, UnsupportedCallbackException,
@@ -266,69 +267,10 @@ public abstract class ConnectionConfiguration {
             context = SSLContext.getInstance("TLS");
         }
 
-        KeyStore ks = null;
-        PasswordCallback pcb = null;
-        KeyManager[] kms = null;
-
-        if ("PKCS11".equals(keystoreType)) {
-                Constructor<?> c = Class.forName("sun.security.pkcs11.SunPKCS11").getConstructor(InputStream.class);
-                String pkcs11Config = "name = SmartCard\nlibrary = " + pkcs11Library;
-                ByteArrayInputStream config = new ByteArrayInputStream(pkcs11Config.getBytes(StandardCharsets.UTF_8));
-                Provider p = (Provider) c.newInstance(config);
-                Security.addProvider(p);
-                ks = KeyStore.getInstance("PKCS11", p);
-                pcb = new PasswordCallback("PKCS11 Password: ", false);
-                callbackHandler.handle(new Callback[] { pcb });
-                ks.load(null, pcb.getPassword());
-        } else if ("Apple".equals(keystoreType)) {
-            ks = KeyStore.getInstance("KeychainStore", "Apple");
-            ks.load(null, null);
-            // pcb = new PasswordCallback("Apple Keychain",false);
-            // pcb.setPassword(null);
-        } else if (keystoreType != null) {
-            ks = KeyStore.getInstance(keystoreType);
-            if (callbackHandler != null && StringUtils.isNotEmpty(keystorePath)) {
-                pcb = new PasswordCallback("Keystore Password: ", false);
-                callbackHandler.handle(new Callback[] { pcb });
-                ks.load(new FileInputStream(keystorePath), pcb.getPassword());
-            } else {
-                InputStream stream = TLSUtils.getDefaultTruststoreStreamIfPossible();
-                try {
-                    // Note that PKCS12 keystores need a password one some Java platforms. Hence we try the famous
-                    // 'changeit' here. See https://bugs.openjdk.java.net/browse/JDK-8194702
-                    char[] password = "changeit".toCharArray();
-                    try {
-                        ks.load(stream, password);
-                    } finally {
-                        CloseableUtil.maybeClose(stream);
-                    }
-                } catch (IOException e) {
-                    LOGGER.log(Level.FINE, "KeyStore load() threw, attempting 'jks' fallback", e);
-
-                    ks = KeyStore.getInstance("jks");
-                    // Open the stream again, so that we read it from the beginning.
-                    stream = TLSUtils.getDefaultTruststoreStreamIfPossible();
-                    try {
-                        ks.load(stream, null);
-                    } finally {
-                        CloseableUtil.maybeClose(stream);
-                    }
-                }
-            }
-        }
-
-        if (ks != null) {
-            String keyManagerFactoryAlgorithm = KeyManagerFactory.getDefaultAlgorithm();
-            KeyManagerFactory kmf = KeyManagerFactory.getInstance(keyManagerFactoryAlgorithm);
-            if (kmf != null) {
-                if (pcb == null) {
-                    kmf.init(ks, null);
-                } else {
-                    kmf.init(ks, pcb.getPassword());
-                    pcb.clearPassword();
-                }
-                kms = kmf.getKeyManagers();
-            }
+        // TODO: Remove the block below once we removed setKeystorePath(), setKeystoreType(), setCallbackHanlder() and
+        // setPKCS11Library() in the builder, and all related fields and the parameters of this function.
+        if (keyManagers == null) {
+            keyManagers = Builder.getKeyManagersFrom(keystoreType, keystorePath, callbackHandler, pkcs11Library);
         }
 
         SmackDaneVerifier daneVerifier = null;
@@ -343,7 +285,7 @@ public abstract class ConnectionConfiguration {
             }
 
             // User requested DANE verification.
-            daneVerifier.init(context, kms, trustManager, null);
+            daneVerifier.init(context, keyManagers, trustManager, secureRandom);
         } else {
             final TrustManager[] trustManagers;
             if (trustManager != null) {
@@ -354,7 +296,7 @@ public abstract class ConnectionConfiguration {
                 trustManagers = null;
             }
 
-            context.init(kms, trustManagers, null);
+            context.init(keyManagers, trustManagers, secureRandom);
         }
 
         return new SmackTlsContext(context, daneVerifier);
@@ -405,7 +347,7 @@ public abstract class ConnectionConfiguration {
 
     /**
      * Returns the TLS security mode used when making the connection. By default,
-     * the mode is {@link SecurityMode#ifpossible}.
+     * the mode is {@link SecurityMode#required}.
      *
      * @return the security mode.
      */
@@ -688,6 +630,8 @@ public abstract class ConnectionConfiguration {
     public abstract static class Builder<B extends Builder<B, C>, C extends ConnectionConfiguration> {
         private SecurityMode securityMode = SecurityMode.required;
         private DnssecMode dnssecMode = DnssecMode.disabled;
+        private KeyManager[] keyManagers;
+        private SecureRandom sslContextSecureRandom;
         private String keystorePath;
         private String keystoreType;
         private String pkcs11Library = "pkcs11.config";
@@ -942,7 +886,12 @@ public abstract class ConnectionConfiguration {
          * @param callbackHandler to obtain information, such as the password or
          * principal information during the SASL authentication.
          * @return a reference to this builder.
+         * @deprecated set a callback-handler aware {@link KeyManager} via {@link #setKeyManager(KeyManager)} or
+         *             {@link #setKeyManagers(KeyManager[])}, created by
+         *             {@link #getKeyManagersFrom(String, String, CallbackHandler, String)}, instead.
          */
+        // TODO: Remove in Smack 4.6.
+        @Deprecated
         public B setCallbackHandler(CallbackHandler callbackHandler) {
             this.callbackHandler = callbackHandler;
             return getThis();
@@ -960,7 +909,7 @@ public abstract class ConnectionConfiguration {
 
         /**
          * Sets the TLS security mode used when making the connection. By default,
-         * the mode is {@link SecurityMode#ifpossible}.
+         * the mode is {@link SecurityMode#required}.
          *
          * @param securityMode the security mode.
          * @return a reference to this builder.
@@ -970,6 +919,47 @@ public abstract class ConnectionConfiguration {
             return getThis();
         }
 
+        /**
+         * Set the {@link KeyManager}s to initialize the {@link SSLContext} used by Smack to establish the XMPP connection.
+         *
+         * @param keyManagers an array of {@link KeyManager}s to initialize the {@link SSLContext} with.
+         * @return a reference to this builder.
+         * @since 4.4.5
+         */
+        public B setKeyManagers(KeyManager[] keyManagers) {
+            this.keyManagers = keyManagers;
+            return getThis();
+        }
+
+        /**
+         * Set the {@link KeyManager}s to initialize the {@link SSLContext} used by Smack to establish the XMPP connection.
+         *
+         * @param keyManager the {@link KeyManager}s to initialize the {@link SSLContext} with.
+         * @return a reference to this builder.
+         * @see #setKeyManagers(KeyManager[])
+         * @since 4.4.5
+         */
+        public B setKeyManager(KeyManager keyManager) {
+            KeyManager[] keyManagers = new KeyManager[] { keyManager };
+            return setKeyManagers(keyManagers);
+        }
+
+        /**
+         * Set the {@link SecureRandom} used to initialize the {@link SSLContext} used by Smack to establish the XMPP
+         * connection. Note that you usually do not need (nor want) to set this. Because if the {@link SecureRandom} is
+         * not explicitly set, Smack will initialize the {@link SSLContext} with <code>null</code> as
+         * {@link SecureRandom} argument. And all sane {@link SSLContext} implementations will then select a safe secure
+         * random source by default.
+         *
+         * @param secureRandom the {@link SecureRandom} to initialize the {@link SSLContext} with.
+         * @return a reference to this builder.
+         * @since 4.4.5
+         */
+        public B setSslContextSecureRandom(SecureRandom secureRandom) {
+            this.sslContextSecureRandom = secureRandom;
+            return getThis();
+        }
+
         /**
          * Sets the path to the keystore file. The key store file contains the
          * certificates that may be used to authenticate the client to the server,
@@ -977,7 +967,12 @@ public abstract class ConnectionConfiguration {
          *
          * @param keystorePath the path to the keystore file.
          * @return a reference to this builder.
+         * @deprecated set a keystore-path aware {@link KeyManager} via {@link #setKeyManager(KeyManager)} or
+         *             {@link #setKeyManagers(KeyManager[])}, created by
+         *             {@link #getKeyManagersFrom(String, String, CallbackHandler, String)}, instead.
          */
+        // TODO: Remove in Smack 4.6.
+        @Deprecated
         public B setKeystorePath(String keystorePath) {
             this.keystorePath = keystorePath;
             return getThis();
@@ -988,7 +983,12 @@ public abstract class ConnectionConfiguration {
          *
          * @param keystoreType the keystore type.
          * @return a reference to this builder.
+         * @deprecated set a key-type aware {@link KeyManager} via {@link #setKeyManager(KeyManager)} or
+         *             {@link #setKeyManagers(KeyManager[])}, created by
+         *             {@link #getKeyManagersFrom(String, String, CallbackHandler, String)}, instead.
          */
+        // TODO: Remove in Smack 4.6.
+        @Deprecated
         public B setKeystoreType(String keystoreType) {
             this.keystoreType = keystoreType;
             return getThis();
@@ -1000,7 +1000,12 @@ public abstract class ConnectionConfiguration {
          *
          * @param pkcs11Library the path to the PKCS11 library file.
          * @return a reference to this builder.
+         * @deprecated set a PKCS11-library aware {@link KeyManager} via {@link #setKeyManager(KeyManager)} or
+         *             {@link #setKeyManagers(KeyManager[])}, created by
+         *             {@link #getKeyManagersFrom(String, String, CallbackHandler, String)}, instead.
          */
+        // TODO: Remove in Smack 4.6.
+        @Deprecated
         public B setPKCS11Library(String pkcs11Library) {
             this.pkcs11Library = pkcs11Library;
             return getThis();
@@ -1276,5 +1281,77 @@ public abstract class ConnectionConfiguration {
         public abstract C build();
 
         protected abstract B getThis();
+
+        public static KeyManager[] getKeyManagersFrom(String keystoreType, String keystorePath,
+                        CallbackHandler callbackHandler, String pkcs11Library)
+                        throws NoSuchMethodException, SecurityException, ClassNotFoundException, KeyStoreException,
+                        NoSuchProviderException, NoSuchAlgorithmException, CertificateException, IOException, InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException, UnsupportedCallbackException, UnrecoverableKeyException {
+            KeyManager[] keyManagers = null;
+            KeyStore ks = null;
+            PasswordCallback pcb = null;
+
+            if ("PKCS11".equals(keystoreType)) {
+                    Constructor<?> c = Class.forName("sun.security.pkcs11.SunPKCS11").getConstructor(InputStream.class);
+                    String pkcs11Config = "name = SmartCard\nlibrary = " + pkcs11Library;
+                    ByteArrayInputStream config = new ByteArrayInputStream(pkcs11Config.getBytes(StandardCharsets.UTF_8));
+                    Provider p = (Provider) c.newInstance(config);
+                    Security.addProvider(p);
+                    ks = KeyStore.getInstance("PKCS11", p);
+                    pcb = new PasswordCallback("PKCS11 Password: ", false);
+                    callbackHandler.handle(new Callback[] { pcb });
+                    ks.load(null, pcb.getPassword());
+            } else if ("Apple".equals(keystoreType)) {
+                ks = KeyStore.getInstance("KeychainStore", "Apple");
+                ks.load(null, null);
+                // pcb = new PasswordCallback("Apple Keychain",false);
+                // pcb.setPassword(null);
+            } else if (keystoreType != null) {
+                ks = KeyStore.getInstance(keystoreType);
+                if (callbackHandler != null && StringUtils.isNotEmpty(keystorePath)) {
+                    pcb = new PasswordCallback("Keystore Password: ", false);
+                    callbackHandler.handle(new Callback[] { pcb });
+                    ks.load(new FileInputStream(keystorePath), pcb.getPassword());
+                } else {
+                    InputStream stream = TLSUtils.getDefaultTruststoreStreamIfPossible();
+                    try {
+                        // Note that PKCS12 keystores need a password one some Java platforms. Hence we try the famous
+                        // 'changeit' here. See https://bugs.openjdk.java.net/browse/JDK-8194702
+                        char[] password = "changeit".toCharArray();
+                        try {
+                            ks.load(stream, password);
+                        } finally {
+                            CloseableUtil.maybeClose(stream);
+                        }
+                    } catch (IOException e) {
+                        LOGGER.log(Level.FINE, "KeyStore load() threw, attempting 'jks' fallback", e);
+
+                        ks = KeyStore.getInstance("jks");
+                        // Open the stream again, so that we read it from the beginning.
+                        stream = TLSUtils.getDefaultTruststoreStreamIfPossible();
+                        try {
+                            ks.load(stream, null);
+                        } finally {
+                            CloseableUtil.maybeClose(stream);
+                        }
+                    }
+                }
+            }
+
+            if (ks != null) {
+                String keyManagerFactoryAlgorithm = KeyManagerFactory.getDefaultAlgorithm();
+                KeyManagerFactory kmf = KeyManagerFactory.getInstance(keyManagerFactoryAlgorithm);
+                if (kmf != null) {
+                    if (pcb == null) {
+                        kmf.init(ks, null);
+                    } else {
+                        kmf.init(ks, pcb.getPassword());
+                        pcb.clearPassword();
+                    }
+                    keyManagers = kmf.getKeyManagers();
+                }
+            }
+
+            return keyManagers;
+        }
     }
 }

smack-core/src/main/java/org/jivesoftware/smack/SmackFuture.java

@@ -170,16 +170,20 @@ public abstract class SmackFuture<V, E extends Exception> implements Future<V>,
         return exception;
     }
 
+    private boolean callbacksInvoked;
+
     protected final synchronized void maybeInvokeCallbacks() {
-        if (cancelled) {
+        if (cancelled || callbacksInvoked) {
             return;
         }
 
         if ((result != null || exception != null) && completionCallback != null) {
+            callbacksInvoked = true;
             completionCallback.accept(this);
         }
 
         if (result != null && successCallback != null) {
+            callbacksInvoked = true;
             AbstractXMPPConnection.asyncGo(new Runnable() {
                 @Override
                 public void run() {
@@ -188,6 +192,7 @@ public abstract class SmackFuture<V, E extends Exception> implements Future<V>,
             });
         }
         else if (exception != null && exceptionCallback != null) {
+            callbacksInvoked = true;
             AbstractXMPPConnection.asyncGo(new Runnable() {
                 @Override
                 public void run() {

smack-core/src/main/java/org/jivesoftware/smack/SmackReactor.java

@@ -221,12 +221,11 @@ public class SmackReactor {
                     selectWait = 0;
                 } else {
                     selectWait = nextScheduledAction.getTimeToDueMillis();
-                }
-
-                if (selectWait < 0) {
+                    if (selectWait <= 0) {
                         // A scheduled action was just released and became ready to execute.
                         return;
                     }
+                }
 
                 // Before we call select, we handle the pending the interest Ops. This will not block since no other
                 // thread is currently in select() at this time.

smack-core/src/main/java/org/jivesoftware/smack/XMPPException.java

@@ -120,6 +120,16 @@ public abstract class XMPPException extends Exception {
             return error;
         }
 
+        /**
+         * Gets the stanza associated with this exception.
+         *
+         * @return the stanza from which this exception was created or {@code null} if the exception is not from a
+         * stanza.
+         */
+        public Stanza getStanza() {
+            return stanza;
+        }
+
         /**
          * Get the request which triggered the error response causing this exception.
          *

smack-core/src/main/java/org/jivesoftware/smack/fsm/StateDescriptorGraph.java

@@ -186,6 +186,10 @@ public class StateDescriptorGraph {
 
         for (GraphVertex<Class<? extends StateDescriptor>> successor : sortedSuccessors) {
             GraphVertex<StateDescriptor> successorVertex = successorStateDescriptors.get(successor.element);
+            if (successorVertex == null) {
+                // The successor does not exist, probably because its module was not enabled.
+                continue;
+            }
             node.addOutgoingEdge(successorVertex);
 
             // Recurse further.

smack-core/src/main/java/org/jivesoftware/smack/packet/IQ.java

@@ -202,7 +202,7 @@ public abstract class IQ extends Stanza implements IqView {
 
         // Add the query section if there is one.
         IQChildElementXmlStringBuilder iqChildElement = getIQChildElementBuilder(
-                        new IQChildElementXmlStringBuilder(this));
+                        new IQChildElementXmlStringBuilder(getChildElementName(), getChildElementNamespace(), null, xml.getXmlEnvironment()));
         // TOOD: Document the cases where iqChildElement is null but childElementName not. And if there are none, change
         // the logic.
         if (iqChildElement == null) {
@@ -399,17 +399,16 @@ public abstract class IQ extends Stanza implements IqView {
 
         private boolean isEmptyElement;
 
-        private IQChildElementXmlStringBuilder(IQ iq) {
-            this(iq.getChildElementName(), iq.getChildElementNamespace());
+        public IQChildElementXmlStringBuilder(ExtensionElement extensionElement,
+                        XmlEnvironment enclosingXmlEnvironment) {
+            this(extensionElement.getElementName(), extensionElement.getNamespace(), extensionElement.getLanguage(),
+                            enclosingXmlEnvironment);
         }
 
-        public IQChildElementXmlStringBuilder(ExtensionElement pe) {
-            this(pe.getElementName(), pe.getNamespace());
-        }
-
-        private IQChildElementXmlStringBuilder(String element, String namespace) {
-            prelude(element, namespace);
-            this.element = element;
+        private IQChildElementXmlStringBuilder(String elementName, String xmlNs, String xmlLang,
+                        XmlEnvironment enclosingXmlEnvironment) {
+            super(elementName, xmlNs, xmlLang, enclosingXmlEnvironment);
+            this.element = elementName;
         }
 
         public void setEmptyElement() {

smack-core/src/main/java/org/jivesoftware/smack/packet/StanzaBuilder.java

@@ -184,6 +184,19 @@ public abstract class StanzaBuilder<B extends StanzaBuilder<B>> implements Stanz
         return getThis();
     }
 
+    public final B removeExtension(String elementName, String namespace) {
+        QName key = new QName(namespace, elementName);
+        extensionElements.remove(key);
+        return getThis();
+    }
+
+    public final B removeExtension(ExtensionElement extension) {
+        QName key = extension.getQName();
+        List<XmlElement> list = extensionElements.getAll(key);
+        list.remove(extension);
+        return getThis();
+    }
+
     public abstract Stanza build();
 
     public abstract B getThis();

smack-core/src/main/java/org/jivesoftware/smack/parsing/ExceptionThrowingCallbackWithHint.java

@@ -34,7 +34,7 @@ public class ExceptionThrowingCallbackWithHint extends ExceptionThrowingCallback
 
     @Override
     public void handleUnparsableStanza(UnparseableStanza packetData) throws IOException {
-        LOGGER.warning("Parsing exception encountered."
+        LOGGER.warning("Parsing exception \"" + packetData.getParsingException().getMessage() + "\" encountered."
                         + " This exception will be re-thrown, leading to a disconnect."
                         + " You can change this behavior by setting a different ParsingExceptionCallback using setParsingExceptionCallback()."
                         + " More information an be found in AbstractXMPPConnection's javadoc.");

smack-core/src/main/java/org/jivesoftware/smack/provider/IQProvider.java

@@ -30,7 +30,7 @@ import org.jivesoftware.smack.xml.XmlPullParserException;
 
 /**
  * <p>
- * <b>Deprecation Notice:</b> This class is deprecated, use {@link IQProvider} instead.
+ * <b>Deprecation Notice:</b> This class is deprecated, use {@link IqProvider} instead.
  * </p>
  * An abstract class for parsing custom IQ packets. Each IQProvider must be registered with
  * the ProviderManager class for it to be used. Every implementation of this

smack-core/src/main/java/org/jivesoftware/smack/sasl/core/SASLAnonymous.java

@@ -60,4 +60,8 @@ public class SASLAnonymous extends SASLMechanism {
         // SASL Anonymous is always successful :)
     }
 
+    @Override
+    public boolean requiresPassword() {
+        return false;
+    }
 }

smack-core/src/main/java/org/jivesoftware/smack/util/CollectionUtil.java

@@ -89,4 +89,11 @@ public class CollectionUtil {
         }
         return Collections.singletonList(element);
     }
+
+    public static <T> Set<T> nullSafeUnmodifiableSet(Set<T> set) {
+        if (set == null) {
+            return Collections.emptySet();
+        }
+        return Collections.unmodifiableSet(set);
+    }
 }

smack-core/src/main/java/org/jivesoftware/smack/util/DoOnce.java

@@ -0,0 +1,29 @@
+/**
+ *
+ * Copyright 2021 Florian Schmaus.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smack.util;
+
+public final class DoOnce {
+
+    private boolean done;
+
+    public void once(Runnable run) {
+        if (done) return;
+
+        done = true;
+        run.run();
+    }
+}

smack-core/src/main/java/org/jivesoftware/smack/util/PacketParserUtils.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2003-2007 Jive Software, 2019 Florian Schmaus.
+ * Copyright 2003-2007 Jive Software, 2019-2021 Florian Schmaus.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -76,9 +76,9 @@ public class PacketParserUtils {
         return getParserFor(new StringReader(stanza));
     }
 
-    public static XmlPullParser getParserFor(InputStream inputStream) throws XmlPullParserException {
+    public static XmlPullParser getParserFor(InputStream inputStream) throws XmlPullParserException, IOException {
         InputStreamReader inputStreamReader = new InputStreamReader(inputStream, StandardCharsets.UTF_8);
-        return SmackXmlParser.newXmlParser(inputStreamReader);
+        return getParserFor(inputStreamReader);
     }
 
     public static XmlPullParser getParserFor(Reader reader) throws XmlPullParserException, IOException {
@@ -501,6 +501,23 @@ public class PacketParserUtils {
         return parseIQ(parser, null);
     }
 
+    public static IqData parseIqData(XmlPullParser parser) throws XmppStringprepException {
+        final String id = parser.getAttributeValue("", "id");
+        IqData iqData = StanzaBuilder.buildIqData(id);
+
+        final Jid to = ParserUtils.getJidAttribute(parser, "to");
+        iqData.to(to);
+
+        final Jid from = ParserUtils.getJidAttribute(parser, "from");
+        iqData.from(from);
+
+        String typeString = parser.getAttributeValue("", "type");
+        final IQ.Type type = IQ.Type.fromString(typeString);
+        iqData.ofType(type);
+
+        return iqData;
+    }
+
     /**
      * Parses an IQ packet.
      *
@@ -518,18 +535,7 @@ public class PacketParserUtils {
         XmlEnvironment iqXmlEnvironment = XmlEnvironment.from(parser, outerXmlEnvironment);
         IQ iqPacket = null;
         StanzaError error = null;
-
-        final String id = parser.getAttributeValue("", "id");
-        IqData iqData = StanzaBuilder.buildIqData(id);
-
-        final Jid to = ParserUtils.getJidAttribute(parser, "to");
-        iqData.to(to);
-
-        final Jid from = ParserUtils.getJidAttribute(parser, "from");
-        iqData.from(from);
-
-        final IQ.Type type = IQ.Type.fromString(parser.getAttributeValue("", "type"));
-        iqData.ofType(type);
+        IqData iqData = parseIqData(parser);
 
         outerloop: while (true) {
             XmlPullParser.Event eventType = parser.next();
@@ -549,8 +555,8 @@ public class PacketParserUtils {
                     if (provider != null) {
                             iqPacket = provider.parse(parser, iqData, outerXmlEnvironment);
                     }
-                    // Note that if we reach this code, it is guranteed that the result IQ contained a child element
-                    // (RFC 6120 § 8.2.3 6) because otherwhise we would have reached the END_ELEMENT first.
+                    // Note that if we reach this code, it is guaranteed that the result IQ contained a child element
+                    // (RFC 6120 § 8.2.3 6) because otherwise we would have reached the END_ELEMENT first.
                     else {
                         // No Provider found for the IQ stanza, parse it to an UnparsedIQ instance
                         // so that the content of the IQ can be examined later on
@@ -571,7 +577,7 @@ public class PacketParserUtils {
         }
         // Decide what to do when an IQ packet was not understood
         if (iqPacket == null) {
-            switch (type) {
+            switch (iqData.getType()) {
             case error:
                 // If an IQ packet wasn't created above, create an empty error IQ packet.
                 iqPacket = new ErrorIQ(error);
@@ -585,10 +591,10 @@ public class PacketParserUtils {
         }
 
         // Set basic values on the iq packet.
-        iqPacket.setStanzaId(id);
-        iqPacket.setTo(to);
-        iqPacket.setFrom(from);
-        iqPacket.setType(type);
+        iqPacket.setStanzaId(iqData.getStanzaId());
+        iqPacket.setTo(iqData.getTo());
+        iqPacket.setFrom(iqData.getFrom());
+        iqPacket.setType(iqData.getType());
         iqPacket.setError(error);
 
         return iqPacket;

smack-core/src/main/java/org/jivesoftware/smack/util/ParserUtils.java

@@ -78,6 +78,7 @@ public class ParserUtils {
                     throws XmlPullParserException, IOException {
         XmlPullParser.Event event = parser.getEventType();
         while (!(event == XmlPullParser.Event.END_ELEMENT && parser.getDepth() == depth)) {
+            assert event != XmlPullParser.Event.END_DOCUMENT;
             event = parser.next();
         }
     }

smack-core/src/main/java/org/jivesoftware/smack/util/StringUtils.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2003-2007 Jive Software, 2016-2020 Florian Schmaus.
+ * Copyright 2003-2007 Jive Software, 2016-2021 Florian Schmaus.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,6 +20,7 @@ package org.jivesoftware.smack.util;
 import java.io.IOException;
 import java.nio.CharBuffer;
 import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Iterator;
@@ -605,4 +606,13 @@ public class StringUtils {
         String[] lines = input.split(PORTABLE_NEWLINE_REGEX);
         return Arrays.asList(lines);
     }
+
+    public static List<String> toStrings(Collection<? extends CharSequence> charSequences) {
+        List<String> res = new ArrayList<>(charSequences.size());
+        for (CharSequence cs : charSequences) {
+            String string = cs.toString();
+            res.add(string);
+        }
+        return res;
+    }
 }

smack-core/src/main/java/org/jivesoftware/smack/util/XmlStringBuilder.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2014-2020 Florian Schmaus
+ * Copyright 2014-2021 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -52,11 +52,13 @@ public class XmlStringBuilder implements Appendable, CharSequence, Element {
     }
 
     public XmlStringBuilder(XmlElement element, XmlEnvironment enclosingXmlEnvironment) {
-        sb = new LazyStringBuilder();
-        halfOpenElement(element);
+        this(element.getElementName(), element.getNamespace(), element.getLanguage(), enclosingXmlEnvironment);
+    }
+
+    public XmlStringBuilder(String elementName, String xmlNs, String xmlLang, XmlEnvironment enclosingXmlEnvironment) {
+        sb = new LazyStringBuilder();
+        halfOpenElement(elementName);
 
-        String xmlNs = element.getNamespace();
-        String xmlLang = element.getLanguage();
         if (enclosingXmlEnvironment == null) {
             xmlnsAttribute(xmlNs);
             xmllangAttribute(xmlLang);
@@ -286,8 +288,7 @@ public class XmlStringBuilder implements Appendable, CharSequence, Element {
 
     public XmlStringBuilder attribute(String name, Enum<?> value) {
         assert value != null;
-        // TODO: Should use toString() instead of name().
-        attribute(name, value.name());
+        attribute(name, value.toString());
         return this;
     }
 

smack-core/src/testFixtures/java/org/jivesoftware/smack/test/util/SmackTestUtil.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2019-2021 Florian Schmaus
+ * Copyright 2019-2022 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -28,9 +28,13 @@ import java.util.function.Predicate;
 import javax.xml.namespace.QName;
 
 import org.jivesoftware.smack.packet.Element;
+import org.jivesoftware.smack.packet.IqData;
 import org.jivesoftware.smack.parsing.SmackParsingException;
+import org.jivesoftware.smack.provider.AbstractProvider;
+import org.jivesoftware.smack.provider.IqProvider;
 import org.jivesoftware.smack.provider.Provider;
 import org.jivesoftware.smack.util.PacketParserUtils;
+import org.jivesoftware.smack.util.ParserUtils;
 import org.jivesoftware.smack.xml.XmlPullParser;
 import org.jivesoftware.smack.xml.XmlPullParserException;
 import org.jivesoftware.smack.xml.XmlPullParserFactory;
@@ -58,41 +62,56 @@ public class SmackTestUtil {
         }
     }
 
-    public static <E extends Element, P extends Provider<E>> E parse(CharSequence xml, Class<P> providerClass, XmlPullParserKind parserKind)
+    public static <E extends Element, P extends AbstractProvider<E>> E parse(CharSequence xml, Class<P> providerClass, XmlPullParserKind parserKind)
                     throws XmlPullParserException, IOException, SmackParsingException {
         P provider = providerClassToProvider(providerClass);
         return parse(xml, provider, parserKind);
     }
 
-    public static <E extends Element, P extends Provider<E>> E parse(InputStream inputStream, Class<P> providerClass, XmlPullParserKind parserKind)
+    public static <E extends Element, P extends AbstractProvider<E>> E parse(InputStream inputStream, Class<P> providerClass, XmlPullParserKind parserKind)
                     throws XmlPullParserException, IOException, SmackParsingException {
         P provider = providerClassToProvider(providerClass);
         return parse(inputStream, provider, parserKind);
     }
 
-    public static <E extends Element, P extends Provider<E>> E parse(Reader reader, Class<P> providerClass, XmlPullParserKind parserKind)
+    public static <E extends Element, P extends AbstractProvider<E>> E parse(Reader reader, Class<P> providerClass, XmlPullParserKind parserKind)
                     throws XmlPullParserException, IOException, SmackParsingException {
         P provider = providerClassToProvider(providerClass);
         return parse(reader, provider, parserKind);
     }
 
-    public static <E extends Element> E parse(CharSequence xml, Provider<E> provider, XmlPullParserKind parserKind)
+    public static <E extends Element> E parse(CharSequence xml, AbstractProvider<E> provider, XmlPullParserKind parserKind)
                     throws XmlPullParserException, IOException, SmackParsingException {
         String xmlString = xml.toString();
         Reader reader = new StringReader(xmlString);
         return parse(reader, provider, parserKind);
     }
 
-    public static <E extends Element> E parse(InputStream inputStream, Provider<E> provider, XmlPullParserKind parserKind)
+    public static <E extends Element> E parse(InputStream inputStream, AbstractProvider<E> provider, XmlPullParserKind parserKind)
                     throws XmlPullParserException, IOException, SmackParsingException {
         InputStreamReader inputStreamReader = new InputStreamReader(inputStream, StandardCharsets.UTF_8);
         return parse(inputStreamReader, provider, parserKind);
     }
 
-    public static <E extends Element> E parse(Reader reader, Provider<E> provider, XmlPullParserKind parserKind)
+    @SuppressWarnings("unchecked")
+    public static <E extends Element> E parse(Reader reader, AbstractProvider<E> abstractProvider, XmlPullParserKind parserKind)
                     throws XmlPullParserException, IOException, SmackParsingException {
         XmlPullParser parser = getParserFor(reader, parserKind);
-        E element = provider.parse(parser);
+
+        final E element;
+        if (abstractProvider instanceof Provider) {
+            Provider<E> provider = (Provider<E>) abstractProvider;
+            element = provider.parse(parser);
+        } else if (abstractProvider instanceof IqProvider) {
+            IqData iqData = PacketParserUtils.parseIqData(parser);
+            parser.next();
+            ParserUtils.forwardToStartElement(parser);
+            IqProvider<?> iqProvider = (IqProvider<?>) abstractProvider;
+            element = (E) iqProvider.parse(parser, iqData);
+        } else {
+            throw new AssertionError();
+        }
+
         return element;
     }
 
@@ -132,7 +151,7 @@ public class SmackTestUtil {
     }
 
     @SuppressWarnings("unchecked")
-    private static <E extends Element, P extends Provider<E>> P providerClassToProvider(Class<P> providerClass) {
+    private static <E extends Element, P extends AbstractProvider<E>> P providerClassToProvider(Class<P> providerClass) {
         P provider;
 
         try {

smack-debug/src/main/java/org/jivesoftware/smackx/debugger/EnhancedDebugger.java

@@ -34,7 +34,13 @@ import java.io.Reader;
 import java.io.Writer;
 import java.net.URL;
 import java.text.SimpleDateFormat;
+import java.time.Duration;
+import java.time.Instant;
+import java.util.ArrayList;
 import java.util.Date;
+import java.util.List;
+import java.util.concurrent.PriorityBlockingQueue;
+import java.util.concurrent.TimeUnit;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
@@ -419,38 +425,11 @@ public class EnhancedDebugger extends SmackDebugger {
         // Create a special Reader that wraps the main Reader and logs data to the GUI.
         ObservableReader debugReader = new ObservableReader(reader);
         readerListener = new ReaderListener() {
-            @Override
-            public void read(final String str) {
-                SwingUtilities.invokeLater(new Runnable() {
-                    @Override
-                    public void run() {
-                        if (EnhancedDebuggerWindow.PERSISTED_DEBUGGER &&
-                                !EnhancedDebuggerWindow.getInstance().isVisible()) {
-                            // Do not add content if the parent is not visible
-                            return;
-                        }
+            private final PriorityBlockingQueue<String> buffer = new PriorityBlockingQueue<>();
 
-                        int index = str.lastIndexOf(">");
-                        if (index != -1) {
-                            if (receivedText.getLineCount() >= EnhancedDebuggerWindow.MAX_TABLE_ROWS) {
-                                try {
-                                    receivedText.replaceRange("", 0, receivedText.getLineEndOffset(0));
-                                }
-                                catch (BadLocationException e) {
-                                    LOGGER.log(Level.SEVERE, "Error with line offset, MAX_TABLE_ROWS is set too low: " + EnhancedDebuggerWindow.MAX_TABLE_ROWS, e);
-                                }
-                            }
-                            receivedText.append(str.substring(0, index + 1));
-                            receivedText.append(NEWLINE);
-                            if (str.length() > index) {
-                                receivedText.append(str.substring(index + 1));
-                            }
-                        }
-                        else {
-                            receivedText.append(str);
-                        }
-                    }
-                });
+            @Override
+            public void read(final String string) {
+                addBatched(string, buffer, receivedText);
             }
         };
         debugReader.addReaderListener(readerListener);
@@ -458,34 +437,11 @@ public class EnhancedDebugger extends SmackDebugger {
         // Create a special Writer that wraps the main Writer and logs data to the GUI.
         ObservableWriter debugWriter = new ObservableWriter(writer);
         writerListener = new WriterListener() {
+            private final PriorityBlockingQueue<String> buffer = new PriorityBlockingQueue<>();
+
             @Override
-            public void write(final String str) {
-                SwingUtilities.invokeLater(new Runnable() {
-                    @Override
-                    public void run() {
-                        if (EnhancedDebuggerWindow.PERSISTED_DEBUGGER &&
-                                !EnhancedDebuggerWindow.getInstance().isVisible()) {
-                            // Do not add content if the parent is not visible
-                            return;
-                        }
-
-                        if (sentText.getLineCount() >= EnhancedDebuggerWindow.MAX_TABLE_ROWS) {
-                            try {
-                                sentText.replaceRange("", 0, sentText.getLineEndOffset(0));
-                            }
-                            catch (BadLocationException e) {
-                                LOGGER.log(Level.SEVERE, "Error with line offset, MAX_TABLE_ROWS is set too low: " + EnhancedDebuggerWindow.MAX_TABLE_ROWS, e);
-                            }
-                        }
-
-                        sentText.append(str);
-                        if (str.endsWith(">")) {
-                            sentText.append(NEWLINE);
-                        }
-                    }
-                });
-
-
+            public void write(final String string) {
+                addBatched(string, buffer, sentText);
             }
         };
         debugWriter.addWriterListener(writerListener);
@@ -497,6 +453,50 @@ public class EnhancedDebugger extends SmackDebugger {
 
     }
 
+    private static void addBatched(String string, PriorityBlockingQueue<String> buffer, JTextArea jTextArea) {
+        buffer.add(string);
+
+        SwingUtilities.invokeLater(() -> {
+            List<String> linesToAdd = new ArrayList<>();
+            String data;
+            Instant start = Instant.now();
+            try {
+                // To reduce overhead/increase performance, try to process up to a certain amount of lines at the
+                // same time, when they arrive in rapid succession.
+                while (linesToAdd.size() < 50
+                                && Duration.between(start, Instant.now()).compareTo(Duration.ofMillis(100)) < 0
+                                && (data = buffer.poll(10, TimeUnit.MILLISECONDS)) != null) {
+                    linesToAdd.add(data);
+                }
+            } catch (InterruptedException e) {
+                LOGGER.log(Level.FINER, "Interrupted wait-for-poll in addBatched(). Process all data now.", e);
+            }
+
+            if (linesToAdd.isEmpty()) {
+                return;
+            }
+
+            if (EnhancedDebuggerWindow.PERSISTED_DEBUGGER && !EnhancedDebuggerWindow.getInstance().isVisible()) {
+                // Do not add content if the parent is not visible
+                return;
+            }
+
+            // Delete lines from the top, if lines to be added will exceed the maximum.
+            int linesToDelete = jTextArea.getLineCount() + linesToAdd.size() - EnhancedDebuggerWindow.MAX_TABLE_ROWS;
+            if (linesToDelete > 0) {
+                try {
+                    jTextArea.replaceRange("", 0, jTextArea.getLineEndOffset(linesToDelete - 1));
+                } catch (BadLocationException e) {
+                    LOGGER.log(Level.SEVERE, "Error with line offset, MAX_TABLE_ROWS is set too low: "
+                                    + EnhancedDebuggerWindow.MAX_TABLE_ROWS, e);
+                }
+            }
+
+            // Add the new content.
+            jTextArea.append(String.join(NEWLINE, linesToAdd));
+        });
+    }
+
     private void addAdhocPacketPanel() {
         // Create UI elements for sending ad-hoc messages.
         final JTextArea adhocMessages = new JTextArea();

smack-experimental/src/main/java/org/jivesoftware/smackx/carbons/CarbonManager.java

@@ -154,8 +154,7 @@ public final class CarbonManager extends Manager {
                 // because we also reset in authenticated() if the stream got not resumed, but for maximum correctness,
                 // also reset here.
                 enabled_state = false;
-                boolean removed = connection().removeSyncStanzaListener(carbonsListener);
-                assert removed;
+                connection().removeSyncStanzaListener(carbonsListener);
             }
             @Override
             public void authenticated(XMPPConnection connection, boolean resumed) {

smack-experimental/src/main/java/org/jivesoftware/smackx/httpfileupload/AbstractHttpUploadException.java

@@ -0,0 +1,101 @@
+/**
+ *
+ * Copyright 2022 Micha Kurvers
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smackx.httpfileupload;
+
+import java.io.IOException;
+import java.net.URL;
+
+import org.jivesoftware.smackx.httpfileupload.element.Slot;
+/**
+ * An exception class to provide additional information in case of exceptions during file uploading.
+ *
+ */
+public abstract class AbstractHttpUploadException extends IOException {
+
+    private static final long serialVersionUID = 1L;
+    private final long fileSize;
+    private final Slot slot;
+
+    protected AbstractHttpUploadException(long fileSize, Slot slot, String message) {
+        this(fileSize, slot, message, null);
+    }
+
+    protected AbstractHttpUploadException(long fileSize, Slot slot, String message, Throwable wrappedThrowable) {
+        super(message, wrappedThrowable);
+        this.fileSize = fileSize;
+        this.slot = slot;
+    }
+
+    public long getFileSize() {
+        return fileSize;
+    }
+
+    public URL getPutUrl() {
+        return slot.getPutUrl();
+    }
+
+    public Slot getSlot() {
+        return slot;
+    }
+
+    /**
+     * Exception thrown when http response returned after upload is not 200.
+     */
+    public static class HttpUploadErrorException extends AbstractHttpUploadException {
+
+        private static final long serialVersionUID = 8494356028399474995L;
+        private final int httpStatus;
+        private final String responseMsg;
+
+        public HttpUploadErrorException(int httpStatus, String responseMsg, long fileSize, Slot slot) {
+            super(fileSize, slot, "Error response " + httpStatus + " from server during file upload: "
+                            + responseMsg + ", file size: " + fileSize + ", put URL: "
+                            + slot.getPutUrl());
+            this.httpStatus = httpStatus;
+            this.responseMsg = responseMsg;
+        }
+
+        public int getHttpStatus() {
+            return httpStatus;
+        }
+
+        public String getResponseMsg() {
+            return responseMsg;
+        }
+
+    }
+
+    /**
+     * Exception thrown when an unexpected exception occurred during the upload.
+     */
+    public static class HttpUploadIOException extends AbstractHttpUploadException {
+
+        private static final long serialVersionUID = 5940866318073349451L;
+        private final IOException wrappedIOException;
+
+        public HttpUploadIOException(long fileSize, Slot slot, IOException cause) {
+            super(fileSize, slot, "Unexpected error occurred during file upload, file size: " + fileSize
+                            + ", put Url: " + slot.getPutUrl(), cause);
+            this.wrappedIOException = cause;
+        }
+
+        public IOException getCausingIOException() {
+            return this.wrappedIOException;
+        }
+
+    }
+}

smack-experimental/src/main/java/org/jivesoftware/smackx/httpfileupload/HttpFileUploadManager.java

@@ -49,6 +49,8 @@ import org.jivesoftware.smack.proxy.ProxyInfo;
 
 import org.jivesoftware.smackx.disco.ServiceDiscoveryManager;
 import org.jivesoftware.smackx.disco.packet.DiscoverInfo;
+import org.jivesoftware.smackx.httpfileupload.AbstractHttpUploadException.HttpUploadErrorException;
+import org.jivesoftware.smackx.httpfileupload.AbstractHttpUploadException.HttpUploadIOException;
 import org.jivesoftware.smackx.httpfileupload.UploadService.Version;
 import org.jivesoftware.smackx.httpfileupload.element.Slot;
 import org.jivesoftware.smackx.httpfileupload.element.SlotRequest;
@@ -494,11 +496,12 @@ public final class HttpFileUploadManager extends Manager {
             case HttpURLConnection.HTTP_NO_CONTENT:
                 break;
             default:
-                throw new IOException("Error response " + status + " from server during file upload: "
-                                + urlConnection.getResponseMessage() + ", file size: " + fileSize + ", put URL: "
-                                + putUrl);
+                throw new HttpUploadErrorException(status, urlConnection.getResponseMessage(), fileSize, slot);
             }
         }
+        catch (IOException e) {
+            throw new HttpUploadIOException(fileSize, slot, e);
+        }
         finally {
             urlConnection.disconnect();
         }

smack-experimental/src/main/java/org/jivesoftware/smackx/mam/MamManager.java

@@ -47,15 +47,17 @@ import org.jivesoftware.smack.util.StringUtils;
 import org.jivesoftware.smackx.commands.AdHocCommandManager;
 import org.jivesoftware.smackx.commands.RemoteCommand;
 import org.jivesoftware.smackx.disco.ServiceDiscoveryManager;
+import org.jivesoftware.smackx.disco.packet.DiscoverInfo;
 import org.jivesoftware.smackx.disco.packet.DiscoverItems;
 import org.jivesoftware.smackx.forward.packet.Forwarded;
-import org.jivesoftware.smackx.mam.MamManager.MamQueryArgs;
+import org.jivesoftware.smackx.mam.element.MamElementFactory;
 import org.jivesoftware.smackx.mam.element.MamElements;
 import org.jivesoftware.smackx.mam.element.MamElements.MamResultExtension;
 import org.jivesoftware.smackx.mam.element.MamFinIQ;
 import org.jivesoftware.smackx.mam.element.MamPrefsIQ;
 import org.jivesoftware.smackx.mam.element.MamPrefsIQ.DefaultBehavior;
 import org.jivesoftware.smackx.mam.element.MamQueryIQ;
+import org.jivesoftware.smackx.mam.element.MamVersion;
 import org.jivesoftware.smackx.mam.filter.MamResultFilter;
 import org.jivesoftware.smackx.muc.MultiUserChat;
 import org.jivesoftware.smackx.rsm.packet.RSMSet;
@@ -225,6 +227,8 @@ public final class MamManager extends Manager {
 
     private final AdHocCommandManager adHocCommandManager;
 
+    private MamVersion mamVersion = null;
+
     private MamManager(XMPPConnection connection, Jid archiveAddress) {
         super(connection);
         this.archiveAddress = archiveAddress;
@@ -250,6 +254,52 @@ public final class MamManager extends Manager {
         return archiveAddress;
     }
 
+    /**
+     * Returns the MAM namespace used by this {@link MamManager}. If the archive does not support any MAM namespace
+     * supported by Smack, null is returned.
+     *
+     * @return the MAM namespace used by this manager, null if MAM is not supported
+     * @throws NoResponseException if there was no response from the remote entity.
+     * @throws XMPPErrorException if there was an XMPP error returned.
+     * @throws NotConnectedException if the XMPP connection is not connected.
+     * @throws InterruptedException if the calling thread was interrupted.
+     */
+    public String getMamNamespace() throws XMPPErrorException, NotConnectedException, NoResponseException, InterruptedException {
+        MamVersion mamVersion = getSupportedMamVersionOrNull();
+        return mamVersion == null ? null : mamVersion.getNamespace();
+    }
+
+    private MamVersion getSupportedMamVersionOrNull() throws XMPPErrorException, NotConnectedException, NoResponseException, InterruptedException {
+        if (mamVersion != null) {
+            return mamVersion;
+        }
+
+        DiscoverInfo info = serviceDiscoveryManager.discoverInfo(getArchiveAddress());
+
+        // Enum values are always returned the order they are declared (see https://docs.oracle.com/javase/specs/jls/se8/html/jls-8.html#jls-8.9.3).
+        // We pick the first version supported by the server.
+        for (MamVersion v : MamVersion.values()) {
+            if (info.containsFeature(v.getNamespace())) {
+                mamVersion = v;
+                break;
+            }
+        }
+
+        return mamVersion;
+    }
+
+    private MamVersion getSupportedMamVersionOrThrow() throws XMPPErrorException, NotConnectedException, NoResponseException, InterruptedException {
+        MamVersion mamVersion = getSupportedMamVersionOrNull();
+        if (mamVersion == null) {
+            throw new UnsupportedOperationException("Message Archive Management is not supported by " + getArchiveAddress());
+        }
+        return mamVersion;
+    }
+
+    private MamElementFactory getElementFactory() throws XMPPErrorException, NotConnectedException, NoResponseException, InterruptedException {
+        return getSupportedMamVersionOrThrow().newElementFactory();
+    }
+
     public static final class MamQueryArgs {
         private final String node;
 
@@ -275,11 +325,11 @@ public final class MamManager extends Manager {
 
         private DataForm dataForm;
 
-        DataForm getDataForm() {
+        DataForm getDataForm(MamVersion version) {
             if (dataForm != null) {
                 return dataForm;
             }
-            DataForm.Builder dataFormBuilder = getNewMamForm();
+            DataForm.Builder dataFormBuilder = getNewMamForm(version);
             dataFormBuilder.addFields(formFields.values());
             dataForm = dataFormBuilder.build();
             return dataForm;
@@ -472,9 +522,9 @@ public final class MamManager extends Manager {
                     NotConnectedException, NotLoggedInException, InterruptedException {
         String queryId = StringUtils.secureUniqueRandomString();
         String node = mamQueryArgs.node;
-        DataForm dataForm = mamQueryArgs.getDataForm();
+        DataForm dataForm = mamQueryArgs.getDataForm(mamVersion);
 
-        MamQueryIQ mamQueryIQ = new MamQueryIQ(queryId, node, dataForm);
+        MamQueryIQ mamQueryIQ = getElementFactory().newQueryIQ(queryId, node, dataForm);
         mamQueryIQ.setType(IQ.Type.set);
         mamQueryIQ.setTo(archiveAddress);
 
@@ -530,7 +580,7 @@ public final class MamManager extends Manager {
                     throws NoResponseException, XMPPErrorException, NotConnectedException,
             InterruptedException, NotLoggedInException {
         String queryId = StringUtils.secureUniqueRandomString();
-        MamQueryIQ mamQueryIq = new MamQueryIQ(queryId, node, null);
+        MamQueryIQ mamQueryIq = getElementFactory().newQueryIQ(queryId, node, null);
         mamQueryIq.setTo(archiveAddress);
 
         MamQueryIQ mamResponseQueryIq = connection().sendIqRequestAndWaitForResponse(mamQueryIq);
@@ -592,7 +642,7 @@ public final class MamManager extends Manager {
         private List<Message> page(RSMSet requestRsmSet) throws NoResponseException, XMPPErrorException,
                         NotConnectedException, NotLoggedInException, InterruptedException {
             String queryId = StringUtils.secureUniqueRandomString();
-            MamQueryIQ mamQueryIQ = new MamQueryIQ(queryId, node, form);
+            MamQueryIQ mamQueryIQ = getElementFactory().newQueryIQ(queryId, node, form);
             mamQueryIQ.setType(IQ.Type.set);
             mamQueryIQ.setTo(archiveAddress);
             mamQueryIQ.addExtension(requestRsmSet);
@@ -696,9 +746,7 @@ public final class MamManager extends Manager {
      * @see <a href="https://xmpp.org/extensions/xep-0313.html#support">XEP-0313 § 7. Determining support</a>
      */
     public boolean isSupported() throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
-        // Note that this may return 'null' but SDM's supportsFeature() does the right thing™ then.
-        Jid archiveAddress = getArchiveAddress();
-        return serviceDiscoveryManager.supportsFeature(archiveAddress, MamElements.NAMESPACE);
+        return getSupportedMamVersionOrNull() != null;
     }
 
     public boolean isAdvancedConfigurationSupported() throws InterruptedException, XMPPException, SmackException {
@@ -720,8 +768,8 @@ public final class MamManager extends Manager {
         throw new SmackException.FeatureNotSupportedException(ADVANCED_CONFIG_NODE, archiveAddress);
     }
 
-    private static DataForm.Builder getNewMamForm() {
-        FormField field = FormField.buildHiddenFormType(MamElements.NAMESPACE);
+    private static DataForm.Builder getNewMamForm(MamVersion version) {
+        FormField field = FormField.buildHiddenFormType(version.getNamespace());
         DataForm.Builder form = DataForm.builder();
         form.addField(field);
         return form;
@@ -765,7 +813,7 @@ public final class MamManager extends Manager {
      */
     public MamPrefsResult retrieveArchivingPreferences() throws NoResponseException, XMPPErrorException,
             NotConnectedException, InterruptedException, NotLoggedInException {
-        MamPrefsIQ mamPrefIQ = new MamPrefsIQ();
+        MamPrefsIQ mamPrefIQ = getElementFactory().newPrefsIQ();
         return queryMamPrefs(mamPrefIQ);
     }
 
@@ -830,6 +878,7 @@ public final class MamManager extends Manager {
     public static final class MamPrefs {
         private final List<Jid> alwaysJids;
         private final List<Jid> neverJids;
+        private final MamVersion mamVersion;
         private DefaultBehavior defaultBehavior;
 
         private MamPrefs(MamPrefsResult mamPrefsResult) {
@@ -837,6 +886,7 @@ public final class MamManager extends Manager {
             this.alwaysJids = new ArrayList<>(mamPrefsIq.getAlwaysJids());
             this.neverJids = new ArrayList<>(mamPrefsIq.getNeverJids());
             this.defaultBehavior = mamPrefsIq.getDefault();
+            this.mamVersion = MamVersion.fromNamespace(mamPrefsIq.getNamespace());
         }
 
         public void setDefaultBehavior(DefaultBehavior defaultBehavior) {
@@ -856,7 +906,7 @@ public final class MamManager extends Manager {
         }
 
         private MamPrefsIQ constructMamPrefsIq() {
-            return new MamPrefsIQ(alwaysJids, neverJids, defaultBehavior);
+            return mamVersion.newElementFactory().newPrefsIQ(alwaysJids, neverJids, defaultBehavior);
         }
     }
 

smack-experimental/src/main/java/org/jivesoftware/smackx/mam/element/MamElementFactory.java

@@ -0,0 +1,94 @@
+/**
+ *
+ * Copyright © 2016-2021 Florian Schmaus and Frank Matheron
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smackx.mam.element;
+
+import java.util.List;
+
+import org.jivesoftware.smack.packet.Message;
+import org.jivesoftware.smack.xml.XmlPullParser;
+import org.jivesoftware.smackx.forward.packet.Forwarded;
+import org.jivesoftware.smackx.rsm.packet.RSMSet;
+import org.jivesoftware.smackx.xdata.packet.DataForm;
+
+import org.jxmpp.jid.Jid;
+
+/**
+ * Factory that creates MAM objects.
+ *
+ * @since 4.5.0
+ */
+public interface MamElementFactory {
+
+    /**
+     * Creates a new {@link MamElementFactory} for the parser based on the namespace of the parser.
+     * @param parser the XML parser to retrieve the MAM namespace from
+     * @return the factory suitable for the MAM namespace
+     */
+    static MamElementFactory forParser(XmlPullParser parser) {
+        String namespace = parser.getNamespace();
+        return MamVersion.fromNamespace(namespace).newElementFactory();
+    }
+
+    /**
+     * Create a MAM result extension class.
+     *
+     * @param queryId id of the query
+     * @param id the message's archive UID
+     * @param forwarded the original message as it was received
+     * @return the result extension
+     */
+    MamElements.MamResultExtension newResultExtension(String queryId, String id, Forwarded<Message> forwarded);
+
+    /**
+     * Create a MAM fin IQ class.
+     *
+     * @param queryId id of the query
+     * @param rsmSet the RSM set included in the {@code <fin/>}
+     * @param complete true if the results returned by the server are complete (no further paging in needed)
+     * @param stable false if the results returned by the sever are unstable (e.g. they might later change in sequence or content)
+     * @return the fin IQ
+     */
+    MamFinIQ newFinIQ(String queryId, RSMSet rsmSet, boolean complete, boolean stable);
+
+    /**
+     * Create a new MAM preferences IQ.
+     *
+     * @param alwaysJids JIDs for which all messages are archived by default
+     * @param neverJids JIDs for which messages are never archived
+     * @param defaultBehavior default archive behavior
+     * @return the prefs IQ
+     */
+    MamPrefsIQ newPrefsIQ(List<Jid> alwaysJids, List<Jid> neverJids, MamPrefsIQ.DefaultBehavior defaultBehavior);
+
+    /**
+     * Construct a new MAM {@code <prefs/>} IQ retrieval request (IQ type 'get').
+     *
+     * @return the prefs IQ
+     */
+    MamPrefsIQ newPrefsIQ();
+
+    /**
+     * Create a new MAM Query IQ.
+     *
+     * @param queryId id of the query
+     * @param node pubsub node id when querying a pubsub node, null when not querying a pubsub node
+     * @param dataForm the dataform containing the query parameters
+     * @return the query IQ
+     */
+    MamQueryIQ newQueryIQ(String queryId, String node, DataForm dataForm);
+
+}

smack-experimental/src/main/java/org/jivesoftware/smackx/mam/element/MamElements.java

@@ -18,15 +18,13 @@ package org.jivesoftware.smackx.mam.element;
 
 import java.util.List;
 
-import javax.xml.namespace.QName;
-
 import org.jivesoftware.smack.packet.Element;
 import org.jivesoftware.smack.packet.ExtensionElement;
 import org.jivesoftware.smack.packet.Message;
 import org.jivesoftware.smack.packet.MessageView;
+import org.jivesoftware.smack.packet.XmlElement;
 import org.jivesoftware.smack.util.StringUtils;
 import org.jivesoftware.smack.util.XmlStringBuilder;
-
 import org.jivesoftware.smackx.forward.packet.Forwarded;
 
 import org.jxmpp.jid.Jid;
@@ -41,8 +39,6 @@ import org.jxmpp.jid.Jid;
  */
 public class MamElements {
 
-    public static final String NAMESPACE = "urn:xmpp:mam:2";
-
     /**
      * MAM result extension class.
      *
@@ -50,18 +46,13 @@ public class MamElements {
      *      Archive Management</a>
      *
      */
-    public static class MamResultExtension implements ExtensionElement {
+    public abstract static class MamResultExtension implements ExtensionElement {
 
         /**
          * result element.
          */
         public static final String ELEMENT = "result";
 
-        /**
-         * The qualified name of the MAM result extension element.
-         */
-        public static final QName QNAME = new QName(NAMESPACE, ELEMENT);
-
         /**
          * id of the result.
          */
@@ -77,20 +68,27 @@ public class MamElements {
          */
         private String queryId;
 
+        protected final MamVersion version;
+
         /**
          * MAM result extension constructor.
          *
+         * @param version TODO javadoc me please
          * @param queryId TODO javadoc me please
          * @param id TODO javadoc me please
          * @param forwarded TODO javadoc me please
          */
-        public MamResultExtension(String queryId, String id, Forwarded<Message> forwarded) {
+        public MamResultExtension(MamVersion version, String queryId, String id, Forwarded<Message> forwarded) {
             if (StringUtils.isEmpty(id)) {
                 throw new IllegalArgumentException("id must not be null or empty");
             }
             if (forwarded == null) {
                 throw new IllegalArgumentException("forwarded must no be null");
             }
+            if (version == null) {
+                throw new IllegalArgumentException("version must not be null");
+            }
+            this.version = version;
             this.id = id;
             this.forwarded = forwarded;
             this.queryId = queryId;
@@ -130,7 +128,7 @@ public class MamElements {
 
         @Override
         public final String getNamespace() {
-            return NAMESPACE;
+            return version.getNamespace();
         }
 
         @Override
@@ -148,7 +146,13 @@ public class MamElements {
         }
 
         public static MamResultExtension from(MessageView message) {
-            return message.getExtension(MamResultExtension.class);
+            for (XmlElement extension : message.getExtensions()) {
+                if (extension instanceof MamResultExtension) {
+                    return (MamResultExtension) extension;
+                }
+            }
+
+            return null;
         }
 
     }

smack-experimental/src/main/java/org/jivesoftware/smackx/mam/element/MamFinIQ.java

@@ -35,11 +35,6 @@ public class MamFinIQ extends IQ {
      */
     public static final String ELEMENT = "fin";
 
-    /**
-     * the IQ NAMESPACE.
-     */
-    public static final String NAMESPACE = MamElements.NAMESPACE;
-
     /**
      * RSM set.
      */
@@ -63,13 +58,14 @@ public class MamFinIQ extends IQ {
     /**
      * MamFinIQ constructor.
      *
+     * @param version TODO javadoc me please
      * @param queryId TODO javadoc me please
      * @param rsmSet TODO javadoc me please
      * @param complete TODO javadoc me please
      * @param stable TODO javadoc me please
      */
-    public MamFinIQ(String queryId, RSMSet rsmSet, boolean complete, boolean stable) {
-        super(ELEMENT, NAMESPACE);
+    public MamFinIQ(MamVersion version, String queryId, RSMSet rsmSet, boolean complete, boolean stable) {
+        super(ELEMENT, version.getNamespace());
         if (rsmSet == null) {
             throw new IllegalArgumentException("rsmSet must not be null");
         }

smack-experimental/src/main/java/org/jivesoftware/smackx/mam/element/MamPrefsIQ.java

@@ -46,11 +46,6 @@ public class MamPrefsIQ extends IQ {
      */
     public static final String ELEMENT = "prefs";
 
-    /**
-     * the IQ NAMESPACE.
-     */
-    public static final String NAMESPACE = MamElements.NAMESPACE;
-
     /**
      * list of always.
      */
@@ -68,9 +63,11 @@ public class MamPrefsIQ extends IQ {
 
     /**
      * Construct a new MAM {@code <prefs/>} IQ retrieval request (IQ type 'get').
+     *
+     * @param version TODO javadoc me please     *
      */
-    public MamPrefsIQ() {
-        super(ELEMENT, NAMESPACE);
+    public MamPrefsIQ(MamVersion version) {
+        super(ELEMENT, version.getNamespace());
         alwaysJids = null;
         neverJids = null;
         defaultBehavior = null;
@@ -79,12 +76,13 @@ public class MamPrefsIQ extends IQ {
     /**
      * MAM preferences IQ constructor.
      *
+     * @param version TODO javadoc me please
      * @param alwaysJids TODO javadoc me please
      * @param neverJids TODO javadoc me please
      * @param defaultBehavior TODO javadoc me please
      */
-    public MamPrefsIQ(List<Jid> alwaysJids, List<Jid> neverJids, DefaultBehavior defaultBehavior) {
-        super(ELEMENT, NAMESPACE);
+    public MamPrefsIQ(MamVersion version, List<Jid> alwaysJids, List<Jid> neverJids, DefaultBehavior defaultBehavior) {
+        super(ELEMENT, version.getNamespace());
         setType(Type.set);
         this.alwaysJids = alwaysJids;
         this.neverJids = neverJids;

smack-experimental/src/main/java/org/jivesoftware/smackx/mam/element/MamQueryIQ.java

@@ -35,11 +35,6 @@ public class MamQueryIQ extends IQ {
      */
     public static final String ELEMENT = QUERY_ELEMENT;
 
-    /**
-     * the MAM query IQ NAMESPACE.
-     */
-    public static final String NAMESPACE = MamElements.NAMESPACE;
-
     private final String queryId;
     private final String node;
     private final DataForm dataForm;
@@ -47,41 +42,45 @@ public class MamQueryIQ extends IQ {
     /**
      * MAM query IQ constructor.
      *
+     * @param version TODO javadoc me please
      * @param queryId TODO javadoc me please
      */
-    public MamQueryIQ(String queryId) {
-        this(queryId, null, null);
+    public MamQueryIQ(MamVersion version, String queryId) {
+        this(version, queryId, null, null);
         setType(IQ.Type.get);
     }
 
     /**
      * MAM query IQ constructor.
      *
+     * @param version TODO javadoc me please
      * @param form TODO javadoc me please
      */
-    public MamQueryIQ(DataForm form) {
-        this(null, null, form);
+    public MamQueryIQ(MamVersion version, DataForm form) {
+        this(version, null, null, form);
     }
 
     /**
      * MAM query IQ constructor.
      *
+     * @param version TODO javadoc me please
      * @param queryId TODO javadoc me please
      * @param form TODO javadoc me please
      */
-    public MamQueryIQ(String queryId, DataForm form) {
-        this(queryId, null, form);
+    public MamQueryIQ(MamVersion version, String queryId, DataForm form) {
+        this(version, queryId, null, form);
     }
 
     /**
      * MAM query IQ constructor.
      *
+     * @param version TODO javadoc me please
      * @param queryId TODO javadoc me please
      * @param node TODO javadoc me please
      * @param dataForm TODO javadoc me please
      */
-    public MamQueryIQ(String queryId, String node, DataForm dataForm) {
-        super(ELEMENT, NAMESPACE);
+    public MamQueryIQ(MamVersion version, String queryId, String node, DataForm dataForm) {
+        super(ELEMENT, version.getNamespace());
         this.queryId = queryId;
         this.node = node;
         this.dataForm = dataForm;
@@ -91,9 +90,9 @@ public class MamQueryIQ extends IQ {
             if (formType == null) {
                 throw new IllegalArgumentException("If a data form is given it must posses a hidden form type field");
             }
-            if (!formType.equals(MamElements.NAMESPACE)) {
+            if (!formType.equals(version.getNamespace())) {
                 throw new IllegalArgumentException(
-                        "Value of the hidden form type field must be '" + MamElements.NAMESPACE + "'");
+                        "Value of the hidden form type field must be '" + version.getNamespace() + "'");
             }
             addExtension(dataForm);
         }

smack-experimental/src/main/java/org/jivesoftware/smackx/mam/element/MamV1ElementFactory.java

@@ -0,0 +1,66 @@
+/**
+ *
+ * Copyright © 2016-2021 Florian Schmaus and Frank Matheron
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smackx.mam.element;
+
+import java.util.List;
+import javax.xml.namespace.QName;
+
+import org.jivesoftware.smack.packet.Message;
+import org.jivesoftware.smackx.forward.packet.Forwarded;
+import org.jivesoftware.smackx.rsm.packet.RSMSet;
+import org.jivesoftware.smackx.xdata.packet.DataForm;
+
+import org.jxmpp.jid.Jid;
+
+class MamV1ElementFactory implements MamElementFactory {
+
+    @Override
+    public MamElements.MamResultExtension newResultExtension(String queryId, String id, Forwarded<Message> forwarded) {
+        return new MamV1ResultExtension(queryId, id, forwarded);
+    }
+
+    @Override
+    public MamFinIQ newFinIQ(String queryId, RSMSet rsmSet, boolean complete, boolean stable) {
+        return new MamFinIQ(MamVersion.MAM1, queryId, rsmSet, complete, stable);
+    }
+
+    @Override
+    public MamPrefsIQ newPrefsIQ(List<Jid> alwaysJids, List<Jid> neverJids, MamPrefsIQ.DefaultBehavior defaultBehavior) {
+        return new MamPrefsIQ(MamVersion.MAM1, alwaysJids, neverJids, defaultBehavior);
+    }
+
+    @Override
+    public MamPrefsIQ newPrefsIQ() {
+        return new MamPrefsIQ(MamVersion.MAM1);
+    }
+
+    @Override
+    public MamQueryIQ newQueryIQ(String queryId, String node, DataForm dataForm) {
+        return new MamQueryIQ(MamVersion.MAM1, queryId, node, dataForm);
+    }
+
+    public static class MamV1ResultExtension extends MamElements.MamResultExtension {
+        /**
+         * The qualified name of the MAM result extension element.
+         */
+        public static final QName QNAME = new QName(MamVersion.MAM1.getNamespace(), ELEMENT);
+
+        MamV1ResultExtension(String queryId, String id, Forwarded<Message> forwarded) {
+            super(MamVersion.MAM1, queryId, id, forwarded);
+        }
+    }
+}

smack-experimental/src/main/java/org/jivesoftware/smackx/mam/element/MamV2ElementFactory.java

@@ -0,0 +1,66 @@
+/**
+ *
+ * Copyright © 2016-2021 Florian Schmaus and Frank Matheron
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smackx.mam.element;
+
+import java.util.List;
+import javax.xml.namespace.QName;
+
+import org.jivesoftware.smack.packet.Message;
+import org.jivesoftware.smackx.forward.packet.Forwarded;
+import org.jivesoftware.smackx.rsm.packet.RSMSet;
+import org.jivesoftware.smackx.xdata.packet.DataForm;
+
+import org.jxmpp.jid.Jid;
+
+class MamV2ElementFactory implements MamElementFactory {
+
+    @Override
+    public MamElements.MamResultExtension newResultExtension(String queryId, String id, Forwarded<Message> forwarded) {
+        return new MamV2ResultExtension(queryId, id, forwarded);
+    }
+
+    @Override
+    public MamFinIQ newFinIQ(String queryId, RSMSet rsmSet, boolean complete, boolean stable) {
+        return new MamFinIQ(MamVersion.MAM2, queryId, rsmSet, complete, stable);
+    }
+
+    @Override
+    public MamPrefsIQ newPrefsIQ(List<Jid> alwaysJids, List<Jid> neverJids, MamPrefsIQ.DefaultBehavior defaultBehavior) {
+        return new MamPrefsIQ(MamVersion.MAM2, alwaysJids, neverJids, defaultBehavior);
+    }
+
+    @Override
+    public MamPrefsIQ newPrefsIQ() {
+        return new MamPrefsIQ(MamVersion.MAM2);
+    }
+
+    @Override
+    public MamQueryIQ newQueryIQ(String queryId, String node, DataForm dataForm) {
+        return new MamQueryIQ(MamVersion.MAM2, queryId, node, dataForm);
+    }
+
+    public static class MamV2ResultExtension extends MamElements.MamResultExtension {
+        /**
+         * The qualified name of the MAM result extension element.
+         */
+        public static final QName QNAME = new QName(MamVersion.MAM2.getNamespace(), ELEMENT);
+
+        MamV2ResultExtension(String queryId, String id, Forwarded<Message> forwarded) {
+            super(MamVersion.MAM2, queryId, id, forwarded);
+        }
+    }
+}

smack-experimental/src/main/java/org/jivesoftware/smackx/mam/element/MamVersion.java

@@ -0,0 +1,69 @@
+/**
+ *
+ * Copyright © 2016-2021 Florian Schmaus and Frank Matheron
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smackx.mam.element;
+
+/**
+ * MAM versions supported by Smack.
+ *
+ * @since 4.5.0
+ */
+public enum MamVersion {
+    // Note that the order in which the enum values are defined, is also the order in which we attempt to find a
+    // supported version. The versions should therefore be listed in order of newest to oldest, so that Smack prefers
+    // using a newer version over an older version.
+    MAM2("urn:xmpp:mam:2") {
+        @Override
+        public MamElementFactory newElementFactory() {
+            return new MamV2ElementFactory();
+        }
+    },
+    MAM1("urn:xmpp:mam:1") {
+        @Override
+        public MamElementFactory newElementFactory() {
+            return new MamV1ElementFactory();
+        }
+    };
+
+    private final String namespace;
+
+    MamVersion(String namespace) {
+        this.namespace = namespace;
+    }
+
+    /**
+     * Each MAM version is identified by its namespace. Returns the namespace for this MAM version.
+     * @return the namespace of the MAM version
+     */
+    public String getNamespace() {
+        return namespace;
+    }
+
+    /**
+     * Creates a new factory that creates IQ's and extension objects for this MAM version.
+     * @return the factory
+     */
+    public abstract MamElementFactory newElementFactory();
+
+    public static MamVersion fromNamespace(String namespace) {
+        for (MamVersion v : MamVersion.values()) {
+            if (v.namespace.equals(namespace)) {
+                return v;
+            }
+        }
+        throw new IllegalArgumentException("Unsupported namespace: " + namespace);
+    }
+}

smack-experimental/src/main/java/org/jivesoftware/smackx/mam/provider/MamFinIQProvider.java

@@ -25,6 +25,7 @@ import org.jivesoftware.smack.util.ParserUtils;
 import org.jivesoftware.smack.xml.XmlPullParser;
 import org.jivesoftware.smack.xml.XmlPullParserException;
 
+import org.jivesoftware.smackx.mam.element.MamElementFactory;
 import org.jivesoftware.smackx.mam.element.MamFinIQ;
 import org.jivesoftware.smackx.rsm.packet.RSMSet;
 import org.jivesoftware.smackx.rsm.provider.RSMSetProvider;
@@ -41,6 +42,7 @@ public class MamFinIQProvider extends IQProvider<MamFinIQ> {
 
     @Override
     public MamFinIQ parse(XmlPullParser parser, int initialDepth, XmlEnvironment xmlEnvironment) throws XmlPullParserException, IOException, SmackParsingException {
+        MamElementFactory elementFactory = MamElementFactory.forParser(parser);
         String queryId = parser.getAttributeValue("", "queryid");
         boolean complete = ParserUtils.getBooleanAttribute(parser, "complete", false);
         boolean stable = ParserUtils.getBooleanAttribute(parser, "stable", true);
@@ -65,7 +67,7 @@ public class MamFinIQProvider extends IQProvider<MamFinIQ> {
             }
         }
 
-        return new MamFinIQ(queryId, rsmSet, complete, stable);
+        return elementFactory.newFinIQ(queryId, rsmSet, complete, stable);
     }
 
 }

smack-experimental/src/main/java/org/jivesoftware/smackx/mam/provider/MamPrefsIQProvider.java

@@ -25,6 +25,7 @@ import org.jivesoftware.smack.provider.IQProvider;
 import org.jivesoftware.smack.xml.XmlPullParser;
 import org.jivesoftware.smack.xml.XmlPullParserException;
 
+import org.jivesoftware.smackx.mam.element.MamElementFactory;
 import org.jivesoftware.smackx.mam.element.MamPrefsIQ;
 import org.jivesoftware.smackx.mam.element.MamPrefsIQ.DefaultBehavior;
 
@@ -41,19 +42,17 @@ import org.jxmpp.jid.impl.JidCreate;
  */
 public class MamPrefsIQProvider extends IQProvider<MamPrefsIQ> {
 
+    public static final MamPrefsIQProvider INSTANCE = new MamPrefsIQProvider();
+
     @Override
     public MamPrefsIQ parse(XmlPullParser parser, int initialDepth, XmlEnvironment xmlEnvironment) throws XmlPullParserException, IOException {
-        String iqType = parser.getAttributeValue("", "type");
+        MamElementFactory elementFactory =  MamElementFactory.forParser(parser);
         String defaultBehaviorString = parser.getAttributeValue("", "default");
         DefaultBehavior defaultBehavior = null;
         if (defaultBehaviorString != null) {
             defaultBehavior = DefaultBehavior.valueOf(defaultBehaviorString);
         }
 
-        if (iqType == null) {
-            iqType = "result";
-        }
-
         List<Jid> alwaysJids = null;
         List<Jid> neverJids = null;
 
@@ -82,7 +81,7 @@ public class MamPrefsIQProvider extends IQProvider<MamPrefsIQ> {
             }
         }
 
-        return new MamPrefsIQ(alwaysJids, neverJids, defaultBehavior);
+        return elementFactory.newPrefsIQ(alwaysJids, neverJids, defaultBehavior);
     }
 
     private static List<Jid> iterateJids(XmlPullParser parser) throws XmlPullParserException, IOException {

smack-experimental/src/main/java/org/jivesoftware/smackx/mam/provider/MamQueryIQProvider.java

@@ -24,6 +24,7 @@ import org.jivesoftware.smack.provider.IQProvider;
 import org.jivesoftware.smack.xml.XmlPullParser;
 import org.jivesoftware.smack.xml.XmlPullParserException;
 
+import org.jivesoftware.smackx.mam.element.MamElementFactory;
 import org.jivesoftware.smackx.mam.element.MamQueryIQ;
 import org.jivesoftware.smackx.xdata.packet.DataForm;
 import org.jivesoftware.smackx.xdata.provider.DataFormProvider;
@@ -41,6 +42,7 @@ public class MamQueryIQProvider extends IQProvider<MamQueryIQ> {
     @Override
     public MamQueryIQ parse(XmlPullParser parser, int initialDepth, XmlEnvironment xmlEnvironment)
                     throws XmlPullParserException, IOException, SmackParsingException {
+        MamElementFactory elementFactory = MamElementFactory.forParser(parser);
         DataForm dataForm = null;
         String queryId = parser.getAttributeValue("", "queryid");
         String node = parser.getAttributeValue("", "node");
@@ -68,7 +70,7 @@ public class MamQueryIQProvider extends IQProvider<MamQueryIQ> {
             }
         }
 
-        return new MamQueryIQ(queryId, node, dataForm);
+        return elementFactory.newQueryIQ(queryId, node, dataForm);
     }
 
 }

smack-experimental/src/main/java/org/jivesoftware/smackx/mam/provider/MamResultProvider.java

@@ -28,6 +28,7 @@ import org.jivesoftware.smack.xml.XmlPullParserException;
 
 import org.jivesoftware.smackx.forward.packet.Forwarded;
 import org.jivesoftware.smackx.forward.provider.ForwardedProvider;
+import org.jivesoftware.smackx.mam.element.MamElementFactory;
 import org.jivesoftware.smackx.mam.element.MamElements.MamResultExtension;
 
 /**
@@ -43,6 +44,7 @@ public class MamResultProvider extends ExtensionElementProvider<MamResultExtensi
     @Override
     public MamResultExtension parse(XmlPullParser parser, int initialDepth, XmlEnvironment xmlEnvironment)
                     throws XmlPullParserException, IOException, SmackParsingException, ParseException {
+        MamElementFactory elementFactory = MamElementFactory.forParser(parser);
         Forwarded<Message> forwarded = null;
         String queryId = parser.getAttributeValue("", "queryid");
         String id = parser.getAttributeValue("", "id");
@@ -69,7 +71,7 @@ public class MamResultProvider extends ExtensionElementProvider<MamResultExtensi
             }
         }
 
-        return new MamResultExtension(queryId, id, forwarded);
+        return elementFactory.newResultExtension(queryId, id, forwarded);
     }
 
 }

smack-experimental/src/main/resources/org.jivesoftware.smack.experimental/experimental.providers

@@ -35,6 +35,26 @@
         <namespace>urn:xmpp:mam:2</namespace>
         <className>org.jivesoftware.smackx.mam.provider.MamResultProvider</className>
     </extensionProvider>
+    <iqProvider>
+        <elementName>prefs</elementName>
+        <namespace>urn:xmpp:mam:1</namespace>
+        <className>org.jivesoftware.smackx.mam.provider.MamPrefsIQProvider</className>
+    </iqProvider>
+    <iqProvider>
+        <elementName>query</elementName>
+        <namespace>urn:xmpp:mam:1</namespace>
+        <className>org.jivesoftware.smackx.mam.provider.MamQueryIQProvider</className>
+    </iqProvider>
+    <iqProvider>
+        <elementName>fin</elementName>
+        <namespace>urn:xmpp:mam:1</namespace>
+        <className>org.jivesoftware.smackx.mam.provider.MamFinIQProvider</className>
+    </iqProvider>
+    <extensionProvider>
+        <elementName>result</elementName>
+        <namespace>urn:xmpp:mam:1</namespace>
+        <className>org.jivesoftware.smackx.mam.provider.MamResultProvider</className>
+    </extensionProvider>
 
     <!-- XEP-0323: Internet of Things - Data -->
     <iqProvider>

smack-experimental/src/test/java/org/jivesoftware/smackx/mam/FiltersTest.java

@@ -23,7 +23,7 @@ import java.util.Date;
 import java.util.List;
 
 import org.jivesoftware.smackx.mam.MamManager.MamQueryArgs;
-import org.jivesoftware.smackx.mam.element.MamElements;
+import org.jivesoftware.smackx.mam.element.MamVersion;
 import org.jivesoftware.smackx.xdata.packet.DataForm;
 
 import org.junit.jupiter.api.Test;
@@ -35,7 +35,7 @@ public class FiltersTest extends MamTest {
 
     private static String getMamXMemberWith(List<String> fieldsNames, List<? extends CharSequence> fieldsValues) {
         String xml = "<x xmlns='jabber:x:data' type='submit'>" + "<field var='FORM_TYPE'>" + "<value>"
-                + MamElements.NAMESPACE + "</value>" + "</field>";
+                + MamVersion.MAM2.getNamespace() + "</value>" + "</field>";
 
         for (int i = 0; i < fieldsNames.size() && i < fieldsValues.size(); i++) {
             xml += "<field var='" + fieldsNames.get(i) + "'>" + "<value>" + fieldsValues.get(i) + "</value>"
@@ -51,7 +51,7 @@ public class FiltersTest extends MamTest {
         Date date = new Date();
 
         MamQueryArgs mamQueryArgs = MamQueryArgs.builder().limitResultsSince(date).build();
-        DataForm dataForm = mamQueryArgs.getDataForm();
+        DataForm dataForm = mamQueryArgs.getDataForm(MamVersion.MAM2);
 
         List<String> fields = new ArrayList<>();
         fields.add("start");
@@ -66,7 +66,7 @@ public class FiltersTest extends MamTest {
         Date date = new Date();
 
         MamQueryArgs mamQueryArgs = MamQueryArgs.builder().limitResultsBefore(date).build();
-        DataForm dataForm = mamQueryArgs.getDataForm();
+        DataForm dataForm = mamQueryArgs.getDataForm(MamVersion.MAM2);
 
         List<String> fields = new ArrayList<>();
         fields.add("end");
@@ -81,7 +81,7 @@ public class FiltersTest extends MamTest {
         Jid jid = JidTestUtil.BARE_JID_1;
 
         MamQueryArgs mamQueryArgs = MamQueryArgs.builder().limitResultsToJid(jid).build();
-        DataForm dataForm = mamQueryArgs.getDataForm();
+        DataForm dataForm = mamQueryArgs.getDataForm(MamVersion.MAM2);
 
         List<String> fields = new ArrayList<>();
         fields.add("with");

smack-experimental/src/test/java/org/jivesoftware/smackx/mam/MamPrefIQProviderTest.java

@@ -19,54 +19,62 @@ package org.jivesoftware.smackx.mam;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
+import java.io.IOException;
 import java.util.List;
 
 import org.jivesoftware.smack.packet.IQ;
+import org.jivesoftware.smack.parsing.SmackParsingException;
+import org.jivesoftware.smack.test.util.SmackTestUtil;
+import org.jivesoftware.smack.test.util.SmackTestUtil.XmlPullParserKind;
 import org.jivesoftware.smack.util.PacketParserUtils;
 import org.jivesoftware.smack.xml.XmlPullParser;
+import org.jivesoftware.smack.xml.XmlPullParserException;
 
 import org.jivesoftware.smackx.mam.element.MamPrefsIQ;
 import org.jivesoftware.smackx.mam.provider.MamPrefsIQProvider;
 
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.EnumSource;
 import org.jxmpp.jid.Jid;
 
 public class MamPrefIQProviderTest extends MamTest {
 
-    private static final String exampleMamPrefsIQ1 = "<iq type='set' id='juliet3'>" + "<prefs xmlns='urn:xmpp:mam:2' default='roster'>"
+    private static final String exampleMamPrefsIQ1 = "<prefs xmlns='urn:xmpp:mam:2' default='roster'>"
             + "<always>" + "<jid>romeo@montague.lit</jid>" + "</always>" + "<never>"
-            + "<jid>montague@montague.lit</jid>" + "</never>" + "</prefs>" + "</iq>";
+            + "<jid>montague@montague.lit</jid>" + "</never>" + "</prefs>";
 
-    private static final String exampleMamPrefsIQ2 = "<iq type='set' id='juliet3'>" + "<prefs xmlns='urn:xmpp:mam:2' default='roster'>"
+    private static final String exampleMamPrefsIQ2 = "<prefs xmlns='urn:xmpp:mam:2' default='roster'>"
             + "<always>" + "<jid>romeo@montague.lit</jid>" + "<jid>montague@montague.lit</jid>" + "</always>"
-            + "<never>" + "</never>" + "</prefs>" + "</iq>";
+            + "<never>" + "</never>" + "</prefs>";
 
-    private static final String exampleMamPrefsIQ3 = "<iq type='get' id='juliet3'>" + "<prefs xmlns='urn:xmpp:mam:2'>" + "</prefs>"
-            + "</iq>";
+    private static final String exampleMamPrefsIQ3 =  "<prefs xmlns='urn:xmpp:mam:2'>" + "</prefs>";
 
     private static final String exampleMamPrefsResultIQ = "<iq type='result' id='juliet3'>"
             + "<prefs xmlns='urn:xmpp:mam:2' default='roster'>" + "<always>" + "<jid>romeo@montague.lit</jid>"
             + "</always>" + "<never>" + "<jid>sarasa@montague.lit</jid>" + "<jid>montague@montague.lit</jid>"
             + "</never>" + "</prefs>" + "</iq>";
 
-    @Test
-    public void checkMamPrefsIQProvider() throws Exception {
-        XmlPullParser parser1 = PacketParserUtils.getParserFor(exampleMamPrefsIQ1);
-        MamPrefsIQ mamPrefIQ1 = new MamPrefsIQProvider().parse(parser1);
+    @ParameterizedTest
+    @EnumSource(value = SmackTestUtil.XmlPullParserKind.class)
+    public void checkMamPrefsIQProvider(XmlPullParserKind parserKind)
+                    throws XmlPullParserException, IOException, SmackParsingException {
+        XmlPullParser parser1 = SmackTestUtil.getParserFor(exampleMamPrefsIQ1, parserKind);
+        MamPrefsIQ mamPrefIQ1 = MamPrefsIQProvider.INSTANCE.parse(parser1);
 
         assertEquals(IQ.Type.set, mamPrefIQ1.getType());
         assertEquals(mamPrefIQ1.getAlwaysJids().get(0).toString(), "romeo@montague.lit");
         assertEquals(mamPrefIQ1.getNeverJids().get(0).toString(), "montague@montague.lit");
 
-        XmlPullParser parser2 = PacketParserUtils.getParserFor(exampleMamPrefsIQ2);
-        MamPrefsIQ mamPrefIQ2 = new MamPrefsIQProvider().parse(parser2);
+        XmlPullParser parser2 = SmackTestUtil.getParserFor(exampleMamPrefsIQ2, parserKind);
+        MamPrefsIQ mamPrefIQ2 = MamPrefsIQProvider.INSTANCE.parse(parser2);
         assertEquals(IQ.Type.set, mamPrefIQ2.getType());
         assertEquals(mamPrefIQ2.getAlwaysJids().get(0).toString(), "romeo@montague.lit");
         assertEquals(mamPrefIQ2.getAlwaysJids().get(1).toString(), "montague@montague.lit");
         assertTrue(mamPrefIQ2.getNeverJids().isEmpty());
 
-        XmlPullParser parser3 = PacketParserUtils.getParserFor(exampleMamPrefsIQ3);
-        MamPrefsIQ mamPrefIQ3 = new MamPrefsIQProvider().parse(parser3);
+        XmlPullParser parser3 = SmackTestUtil.getParserFor(exampleMamPrefsIQ3, parserKind);
+        MamPrefsIQ mamPrefIQ3 = MamPrefsIQProvider.INSTANCE.parse(parser3);
         assertEquals(IQ.Type.set, mamPrefIQ3.getType());
     }
 

smack-experimental/src/test/java/org/jivesoftware/smackx/mam/MamTest.java

@@ -23,6 +23,7 @@ import org.jivesoftware.smack.DummyConnection;
 import org.jivesoftware.smack.XMPPConnection;
 import org.jivesoftware.smack.test.util.SmackTestSuite;
 
+import org.jivesoftware.smackx.mam.element.MamVersion;
 import org.jivesoftware.smackx.xdata.packet.DataForm;
 
 import org.junit.jupiter.api.BeforeAll;
@@ -47,9 +48,9 @@ public class MamTest extends SmackTestSuite {
 
     protected DataForm getNewMamForm() throws NoSuchMethodException, SecurityException, IllegalAccessException,
             IllegalArgumentException, InvocationTargetException {
-        Method methodGetNewMamForm = MamManager.class.getDeclaredMethod("getNewMamForm");
+        Method methodGetNewMamForm = MamManager.class.getDeclaredMethod("getNewMamForm", MamVersion.class);
         methodGetNewMamForm.setAccessible(true);
-        DataForm.Builder dataFormBuilder = (DataForm.Builder) methodGetNewMamForm.invoke(mamManager);
+        DataForm.Builder dataFormBuilder = (DataForm.Builder) methodGetNewMamForm.invoke(mamManager, MamVersion.MAM2);
         return dataFormBuilder.build();
     }
 

smack-experimental/src/test/java/org/jivesoftware/smackx/mam/PagingTest.java

@@ -22,6 +22,7 @@ import org.jivesoftware.smack.packet.IQ;
 import org.jivesoftware.smack.packet.StreamOpen;
 
 import org.jivesoftware.smackx.mam.element.MamQueryIQ;
+import org.jivesoftware.smackx.mam.element.MamVersion;
 import org.jivesoftware.smackx.rsm.packet.RSMSet;
 import org.jivesoftware.smackx.xdata.packet.DataForm;
 
@@ -40,7 +41,7 @@ public class PagingTest extends MamTest {
         int max = 10;
         RSMSet rsmSet = new RSMSet(max);
 
-        MamQueryIQ mamQueryIQ = new MamQueryIQ(queryId, dataForm);
+        MamQueryIQ mamQueryIQ = new MamQueryIQ(MamVersion.MAM2, queryId, dataForm);
         mamQueryIQ.setStanzaId("sarasa");
         mamQueryIQ.setType(IQ.Type.set);
         mamQueryIQ.addExtension(rsmSet);

smack-experimental/src/test/java/org/jivesoftware/smackx/mam/PreferencesTest.java

@@ -23,9 +23,9 @@ import java.util.List;
 
 import org.jivesoftware.smack.packet.StreamOpen;
 
-import org.jivesoftware.smackx.mam.element.MamElements;
 import org.jivesoftware.smackx.mam.element.MamPrefsIQ;
 import org.jivesoftware.smackx.mam.element.MamPrefsIQ.DefaultBehavior;
+import org.jivesoftware.smackx.mam.element.MamVersion;
 
 import org.junit.jupiter.api.Test;
 import org.jxmpp.jid.Jid;
@@ -33,16 +33,16 @@ import org.jxmpp.jid.impl.JidCreate;
 
 public class PreferencesTest {
 
-    private static final String retrievePrefsStanzaExample = "<iq id='sarasa' type='get'>" + "<prefs xmlns='" + MamElements.NAMESPACE
+    private static final String retrievePrefsStanzaExample = "<iq id='sarasa' type='get'>" + "<prefs xmlns='" + MamVersion.MAM2.getNamespace()
             + "'/>" + "</iq>";
 
-    private static final String updatePrefsStanzaExample = "<iq id='sarasa' type='set'>" + "<prefs xmlns='" + MamElements.NAMESPACE
+    private static final String updatePrefsStanzaExample = "<iq id='sarasa' type='set'>" + "<prefs xmlns='" + MamVersion.MAM2.getNamespace()
             + "' default='roster'>" + "<always>" + "<jid>romeo@montague.lit</jid>" + "<jid>other@montague.lit</jid>"
             + "</always>" + "<never>" + "<jid>montague@montague.lit</jid>" + "</never>" + "</prefs>" + "</iq>";
 
     @Test
     public void checkRetrievePrefsStanza() throws Exception {
-        MamPrefsIQ mamPrefIQ = new MamPrefsIQ();
+        MamPrefsIQ mamPrefIQ = MamVersion.MAM2.newElementFactory().newPrefsIQ();
         mamPrefIQ.setStanzaId("sarasa");
         assertEquals(mamPrefIQ.toXML(StreamOpen.CLIENT_NAMESPACE).toString(), retrievePrefsStanzaExample);
     }
@@ -56,7 +56,7 @@ public class PreferencesTest {
         List<Jid> neverJids = new ArrayList<>();
         neverJids.add(JidCreate.from("montague@montague.lit"));
 
-        MamPrefsIQ mamPrefIQ =  new MamPrefsIQ(alwaysJids, neverJids, DefaultBehavior.roster);
+        MamPrefsIQ mamPrefIQ =  MamVersion.MAM2.newElementFactory().newPrefsIQ(alwaysJids, neverJids, DefaultBehavior.roster);
         mamPrefIQ.setStanzaId("sarasa");
         assertEquals(mamPrefIQ.toXML(StreamOpen.CLIENT_NAMESPACE).toString(), updatePrefsStanzaExample);
     }

smack-experimental/src/test/java/org/jivesoftware/smackx/mam/QueryArchiveTest.java

@@ -29,9 +29,9 @@ import org.jivesoftware.smack.packet.StreamOpen;
 
 import org.jivesoftware.smackx.delay.packet.DelayInformation;
 import org.jivesoftware.smackx.forward.packet.Forwarded;
-import org.jivesoftware.smackx.mam.element.MamElements;
 import org.jivesoftware.smackx.mam.element.MamElements.MamResultExtension;
 import org.jivesoftware.smackx.mam.element.MamQueryIQ;
+import org.jivesoftware.smackx.mam.element.MamVersion;
 import org.jivesoftware.smackx.xdata.packet.DataForm;
 
 import org.junit.jupiter.api.Test;
@@ -41,7 +41,7 @@ public class QueryArchiveTest extends MamTest {
 
     private static final String mamSimpleQueryIQ = "<iq id='sarasa' type='set'>" + "<query xmlns='urn:xmpp:mam:2' queryid='testid'>"
             + "<x xmlns='jabber:x:data' type='submit'>" + "<field var='FORM_TYPE'>" + "<value>"
-            + MamElements.NAMESPACE + "</value>" + "</field>" + "</x>" + "</query>" + "</iq>";
+            + MamVersion.MAM2.getNamespace() + "</value>" + "</field>" + "</x>" + "</query>" + "</iq>";
 
     private static final String mamQueryResultExample = "<message to='hag66@shakespeare.lit/pda' from='coven@chat.shakespeare.lit' id='iasd207'>"
             + "<result xmlns='urn:xmpp:mam:2' queryid='g27' id='34482-21985-73620'>"
@@ -54,7 +54,7 @@ public class QueryArchiveTest extends MamTest {
     @Test
     public void checkMamQueryIQ() throws Exception {
         DataForm dataForm = getNewMamForm();
-        MamQueryIQ mamQueryIQ = new MamQueryIQ(queryId, dataForm);
+        MamQueryIQ mamQueryIQ = new MamQueryIQ(MamVersion.MAM2, queryId, dataForm);
         mamQueryIQ.setType(IQ.Type.set);
         mamQueryIQ.setStanzaId("sarasa");
         assertEquals(mamQueryIQ.toXML(StreamOpen.CLIENT_NAMESPACE).toString(), mamSimpleQueryIQ);
@@ -80,7 +80,7 @@ public class QueryArchiveTest extends MamTest {
 
         Forwarded<Message> forwarded = new Forwarded<>(forwardedMessage, delay);
 
-        message.addExtension(new MamResultExtension("g27", "34482-21985-73620", forwarded));
+        message.addExtension(MamVersion.MAM2.newElementFactory().newResultExtension("g27", "34482-21985-73620", forwarded));
 
         assertEquals(mamQueryResultExample, message.toXML(StreamOpen.CLIENT_NAMESPACE).toString());
 

smack-experimental/src/test/java/org/jivesoftware/smackx/mam/ResultsLimitTest.java

@@ -22,8 +22,8 @@ import org.jivesoftware.smack.packet.IQ;
 import org.jivesoftware.smack.packet.StreamOpen;
 
 import org.jivesoftware.smackx.mam.MamManager.MamQueryArgs;
-import org.jivesoftware.smackx.mam.element.MamElements;
 import org.jivesoftware.smackx.mam.element.MamQueryIQ;
+import org.jivesoftware.smackx.mam.element.MamVersion;
 import org.jivesoftware.smackx.xdata.packet.DataForm;
 
 import org.junit.jupiter.api.Test;
@@ -32,13 +32,13 @@ public class ResultsLimitTest extends MamTest {
 
     private static final String resultsLimitStanza = "<iq id='sarasa' type='set'>" + "<query xmlns='urn:xmpp:mam:2' queryid='testid'>"
             + "<x xmlns='jabber:x:data' type='submit'>" + "<field var='FORM_TYPE'>" + "<value>"
-            + MamElements.NAMESPACE + "</value>" + "</field>" + "</x>" + "<set xmlns='http://jabber.org/protocol/rsm'>"
+            + MamVersion.MAM2.getNamespace() + "</value>" + "</field>" + "</x>" + "<set xmlns='http://jabber.org/protocol/rsm'>"
             + "<max>10</max>" + "</set>" + "</query>" + "</iq>";
 
     @Test
     public void checkResultsLimit() throws Exception {
         DataForm dataForm = getNewMamForm();
-        MamQueryIQ mamQueryIQ = new MamQueryIQ(queryId, dataForm);
+        MamQueryIQ mamQueryIQ = new MamQueryIQ(MamVersion.MAM2, queryId, dataForm);
         mamQueryIQ.setType(IQ.Type.set);
         mamQueryIQ.setStanzaId("sarasa");
 

smack-experimental/src/test/java/org/jivesoftware/smackx/mam/RetrieveFormFieldsTest.java

@@ -22,8 +22,8 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
 import org.jivesoftware.smack.packet.StreamOpen;
 
 import org.jivesoftware.smackx.mam.MamManager.MamQueryArgs;
-import org.jivesoftware.smackx.mam.element.MamElements;
 import org.jivesoftware.smackx.mam.element.MamQueryIQ;
+import org.jivesoftware.smackx.mam.element.MamVersion;
 import org.jivesoftware.smackx.xdata.FormField;
 import org.jivesoftware.smackx.xdata.packet.DataForm;
 
@@ -32,18 +32,18 @@ import org.jxmpp.jid.JidTestUtil;
 
 public class RetrieveFormFieldsTest extends MamTest {
 
-    private static final String retrieveFormFieldStanza = "<iq id='sarasa' type='get'>" + "<query xmlns='" + MamElements.NAMESPACE
+    private static final String retrieveFormFieldStanza = "<iq id='sarasa' type='get'>" + "<query xmlns='" + MamVersion.MAM2.getNamespace()
             + "' queryid='testid'></query>" + "</iq>";
 
     private static final String additionalFieldsStanza = "<x xmlns='jabber:x:data' type='submit'>" + "<field var='FORM_TYPE'>"
-            + "<value>" + MamElements.NAMESPACE + "</value>" + "</field>"
+            + "<value>" + MamVersion.MAM2.getNamespace() + "</value>" + "</field>"
             + "<field var='urn:example:xmpp:free-text-search'>" + "<value>Hi</value>" + "</field>"
             + "<field var='urn:example:xmpp:stanza-content'>" + "<value>one@exampleone.org</value>" + "</field>"
             + "</x>";
 
     @Test
     public void checkRetrieveFormFieldsStanza() throws Exception {
-        MamQueryIQ mamQueryIQ = new MamQueryIQ(queryId);
+        MamQueryIQ mamQueryIQ = new MamQueryIQ(MamVersion.MAM2, queryId);
         mamQueryIQ.setStanzaId("sarasa");
 
         assertEquals(retrieveFormFieldStanza, mamQueryIQ.toXML(StreamOpen.CLIENT_NAMESPACE).toString());
@@ -63,7 +63,7 @@ public class RetrieveFormFieldsTest extends MamTest {
                         .withAdditionalFormField(field1)
                         .withAdditionalFormField(field2)
                         .build();
-        DataForm dataForm = mamQueryArgs.getDataForm();
+        DataForm dataForm = mamQueryArgs.getDataForm(MamVersion.MAM2);
 
         String dataFormResult = dataForm.toXML().toString();
 

smack-extensions/src/main/java/org/jivesoftware/smackx/bytestreams/ibb/packet/DataPacketExtension.java

@@ -153,7 +153,7 @@ public class DataPacketExtension implements ExtensionElement {
 
     @Override
     public XmlStringBuilder toXML(org.jivesoftware.smack.packet.XmlEnvironment enclosingNamespace) {
-        XmlStringBuilder xml = getIQChildElementBuilder(new IQChildElementXmlStringBuilder(this));
+        XmlStringBuilder xml = getIQChildElementBuilder(new IQChildElementXmlStringBuilder(this, enclosingNamespace));
         xml.closeElement(this);
         return xml;
     }

smack-extensions/src/main/java/org/jivesoftware/smackx/bytestreams/socks5/Socks5BytestreamManager.java

@@ -615,10 +615,8 @@ public final class Socks5BytestreamManager extends Manager implements Bytestream
         if (annouceLocalStreamHost) {
             // add local proxy on first position if exists
             List<StreamHost> localProxies = getLocalStreamHost();
-            if (localProxies != null) {
             streamHosts.addAll(localProxies);
         }
-        }
 
         // query SOCKS5 proxies for network settings
         for (Jid proxy : proxies) {
@@ -652,12 +650,14 @@ public final class Socks5BytestreamManager extends Manager implements Bytestream
 
     /**
      * Returns the stream host information of the local SOCKS5 proxy containing the IP address and
-     * the port or null if local SOCKS5 proxy is not running.
+     * the port. The returned list may be empty if the local SOCKS5 proxy is not running.
      *
-     * @return the stream host information of the local SOCKS5 proxy or null if local SOCKS5 proxy
-     *         is not running
+     * @return the stream host information of the local SOCKS5 proxy
      */
     public List<StreamHost> getLocalStreamHost() {
+        // Ensure that the local SOCKS5 proxy is running (if enabled).
+        Socks5Proxy.getSocks5Proxy();
+
         List<StreamHost> streamHosts = new ArrayList<>();
 
         XMPPConnection connection = connection();

smack-extensions/src/main/java/org/jivesoftware/smackx/caps/EntityCapsManager.java

@@ -700,7 +700,7 @@ public final class EntityCapsManager extends Manager {
             for (FormField f : fs) {
                 sb.append(f.getFieldName());
                 sb.append('<');
-                formFieldValuesToCaps(f.getRawValues(), sb);
+                formFieldValuesToCaps(f.getRawValueCharSequences(), sb);
             }
         }
 

smack-extensions/src/main/java/org/jivesoftware/smackx/disco/ServiceDiscoveryManager.java

@@ -921,6 +921,10 @@ public final class ServiceDiscoveryManager extends Manager {
         return entityCapabilitiesChangedListeners.add(entityCapabilitiesChangedListener);
     }
 
+    public boolean removeEntityCapabilitiesChangedListener(EntityCapabilitiesChangedListener entityCapabilitiesChangedListener) {
+        return entityCapabilitiesChangedListeners.remove(entityCapabilitiesChangedListener);
+    }
+
     private static final int RENEW_ENTITY_CAPS_DELAY_MILLIS = 25;
 
     private ScheduledAction renewEntityCapsScheduledAction;

smack-extensions/src/main/java/org/jivesoftware/smackx/disco/packet/DiscoverInfo.java

@@ -258,6 +258,14 @@ public class DiscoverInfo extends IQ implements DiscoverInfoView {
         return features.contains(new Feature(feature));
     }
 
+    public static boolean nullSafeContainsFeature(DiscoverInfo discoverInfo, CharSequence feature) {
+        if (discoverInfo == null) {
+            return false;
+        }
+
+        return discoverInfo.containsFeature(feature);
+    }
+
     @Override
     protected IQChildElementXmlStringBuilder getIQChildElementBuilder(IQChildElementXmlStringBuilder xml) {
         xml.optAttribute("node", getNode());

smack-extensions/src/main/java/org/jivesoftware/smackx/formtypes/FormFieldRegistry.java

@@ -68,6 +68,12 @@ public class FormFieldRegistry {
         }
     }
 
+    public static void register(String formType, FormField.Type fieldType, String... fieldNames) {
+        for (String fieldName : fieldNames) {
+            register(formType, fieldName, fieldType);
+        }
+    }
+
     public static void register(String formType, String fieldName, FormField.Type fieldType) {
         StringUtils.requireNotNullNorEmpty(fieldName, "fieldName must be provided");
         Objects.requireNonNull(fieldType);

smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/JingleUtil.java

@@ -53,7 +53,7 @@ public class JingleUtil {
                                         JingleContentDescription description,
                                         JingleContentTransport transport) {
 
-        Jingle.Builder jb = Jingle.getBuilder();
+        Jingle.Builder jb = Jingle.builder(connection);
         jb.setAction(JingleAction.session_initiate)
                 .setSessionId(sessionId)
                 .setInitiator(connection.getUser());
@@ -118,7 +118,7 @@ public class JingleUtil {
                                       JingleContentDescription description,
                                       JingleContentTransport transport) {
 
-        Jingle.Builder jb = Jingle.getBuilder();
+        Jingle.Builder jb = Jingle.builder(connection);
         jb.setResponder(connection.getUser())
                 .setAction(JingleAction.session_accept)
                 .setSessionId(sessionId);
@@ -153,7 +153,7 @@ public class JingleUtil {
     }
 
     public Jingle createSessionTerminate(FullJid recipient, String sessionId, JingleReason reason) {
-        Jingle.Builder jb = Jingle.getBuilder();
+        Jingle.Builder jb = Jingle.builder(connection);
         jb.setAction(JingleAction.session_terminate)
                 .setSessionId(sessionId)
                 .setReason(reason);
@@ -232,7 +232,7 @@ public class JingleUtil {
 
     public Jingle createSessionTerminateContentCancel(FullJid recipient, String sessionId,
                                                       JingleContent.Creator contentCreator, String contentName) {
-        Jingle.Builder jb = Jingle.getBuilder();
+        Jingle.Builder jb = Jingle.builder(connection);
         jb.setAction(JingleAction.session_terminate)
                 .setSessionId(sessionId);
 
@@ -314,7 +314,7 @@ public class JingleUtil {
     }
 
     public Jingle createSessionPing(FullJid recipient, String sessionId) {
-        Jingle.Builder jb = Jingle.getBuilder();
+        Jingle.Builder jb = Jingle.builder(connection);
         jb.setSessionId(sessionId)
                 .setAction(JingleAction.session_info);
 
@@ -343,7 +343,7 @@ public class JingleUtil {
     public Jingle createTransportReplace(FullJid recipient, FullJid initiator, String sessionId,
                                          JingleContent.Creator contentCreator, String contentName,
                                          JingleContentTransport transport) {
-        Jingle.Builder jb = Jingle.getBuilder();
+        Jingle.Builder jb = Jingle.builder(connection);
         jb.setInitiator(initiator)
                 .setSessionId(sessionId)
                 .setAction(JingleAction.transport_replace);
@@ -370,7 +370,7 @@ public class JingleUtil {
     public Jingle createTransportAccept(FullJid recipient, FullJid initiator, String sessionId,
                                         JingleContent.Creator contentCreator, String contentName,
                                         JingleContentTransport transport) {
-        Jingle.Builder jb = Jingle.getBuilder();
+        Jingle.Builder jb = Jingle.builder(connection);
         jb.setAction(JingleAction.transport_accept)
                 .setInitiator(initiator)
                 .setSessionId(sessionId);
@@ -397,7 +397,7 @@ public class JingleUtil {
     public Jingle createTransportReject(FullJid recipient, FullJid initiator, String sessionId,
                                         JingleContent.Creator contentCreator, String contentName,
                                         JingleContentTransport transport) {
-        Jingle.Builder jb = Jingle.getBuilder();
+        Jingle.Builder jb = Jingle.builder(connection);
         jb.setAction(JingleAction.transport_reject)
                 .setInitiator(initiator)
                 .setSessionId(sessionId);

smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/element/Jingle.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2003-2007 Jive Software, 2014-2017 Florian Schmaus
+ * Copyright 2003-2007 Jive Software, 2014-2021 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,7 +21,11 @@ import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 
+import org.jivesoftware.smack.XMPPConnection;
 import org.jivesoftware.smack.packet.IQ;
+import org.jivesoftware.smack.packet.IqBuilder;
+import org.jivesoftware.smack.packet.IqData;
+import org.jivesoftware.smack.packet.id.StandardStanzaIdSource;
 import org.jivesoftware.smack.util.Objects;
 import org.jivesoftware.smack.util.StringUtils;
 
@@ -65,9 +69,9 @@ public final class Jingle extends IQ {
 
     private final List<JingleContent> contents;
 
-    private Jingle(String sessionId, JingleAction action, FullJid initiator, FullJid responder, JingleReason reason,
+    private Jingle(Builder builder, String sessionId, JingleAction action, FullJid initiator, FullJid responder, JingleReason reason,
                     List<JingleContent> contents) {
-        super(ELEMENT, NAMESPACE);
+        super(builder, ELEMENT, NAMESPACE);
         this.sessionId = StringUtils.requireNotNullNorEmpty(sessionId, "Jingle session ID must not be null");
         this.action = Objects.requireNonNull(action, "Jingle action must not be null");
         this.initiator = initiator;
@@ -169,11 +173,31 @@ public final class Jingle extends IQ {
         return xml;
     }
 
+    /**
+     * Deprecated, do not use.
+     *
+     * @return a builder.
+     * @deprecated use {@link #builder(XMPPConnection)} instead.
+     */
+    @Deprecated
+    // TODO: Remove in Smack 4.6.
     public static Builder getBuilder() {
-        return new Builder();
+        return builder(StandardStanzaIdSource.DEFAULT.getNewStanzaId());
     }
 
-    public static final class Builder {
+    public static Builder builder(XMPPConnection connection) {
+        return new Builder(connection);
+    }
+
+    public static Builder builder(IqData iqData) {
+        return new Builder(iqData);
+    }
+
+    public static Builder builder(String stanzaId) {
+        return new Builder(stanzaId);
+    }
+
+    public static final class Builder extends IqBuilder<Builder, Jingle> {
         private String sid;
 
         private JingleAction action;
@@ -186,7 +210,16 @@ public final class Jingle extends IQ {
 
         private List<JingleContent> contents;
 
-        private Builder() {
+        Builder(IqData iqCommon) {
+            super(iqCommon);
+        }
+
+        Builder(XMPPConnection connection) {
+            super(connection);
+        }
+
+        Builder(String stanzaId) {
+            super(stanzaId);
         }
 
         public Builder setSessionId(String sessionId) {
@@ -228,8 +261,14 @@ public final class Jingle extends IQ {
             return this;
         }
 
+        @Override
         public Jingle build() {
-            return new Jingle(sid, action, initiator, responder, reason, contents);
+            return new Jingle(this, sid, action, initiator, responder, reason, contents);
+        }
+
+        @Override
+        public Builder getThis() {
+            return this;
         }
     }
 }

smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/element/JingleContent.java

@@ -145,6 +145,11 @@ public final class JingleContent implements XmlElement {
         xml.optAttribute(DISPOSITION_ATTRIBUTE_NAME, disposition);
         xml.attribute(NAME_ATTRIBUTE_NAME, name);
         xml.optAttribute(SENDERS_ATTRIBUTE_NAME, senders);
+
+        if (description == null && transport == null) {
+            return xml.closeEmptyElement();
+        }
+
         xml.rightAngleBracket();
 
         xml.optAppend(description);

smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/element/JingleReason.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2017-2021 Florian Schmaus
+ * Copyright 2017-2022 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -34,6 +34,7 @@ public class JingleReason implements XmlElement {
 
     public static final String ELEMENT = "reason";
     public static final String NAMESPACE = Jingle.NAMESPACE;
+    public static final String TEXT_ELEMENT = "text";
 
     public static AlternativeSession AlternativeSession(String sessionId) {
         return new AlternativeSession(sessionId);
@@ -105,9 +106,17 @@ public class JingleReason implements XmlElement {
     }
 
     protected final Reason reason;
+    private final String text;
+    private final XmlElement element;
 
     public JingleReason(Reason reason) {
+        this(reason, null, null);
+    }
+
+    public JingleReason(Reason reason, String text, XmlElement element) {
         this.reason = reason;
+        this.text = text;
+        this.element = element;
     }
 
     @Override
@@ -120,12 +129,34 @@ public class JingleReason implements XmlElement {
         return NAMESPACE;
     }
 
+    /**
+     * An optional text that provides human-readable information about the reason for the action.
+     *
+     * @return a human-readable text with information regarding this reason or <code>null</code>.
+     * @since 4.4.5
+     */
+    public String getText() {
+        return text;
+    }
+
+    /**
+     * An optional element that provides more detailed machine-readable information about the reason for the action.
+     *
+     * @return an element with machine-readable information about this reason or <code>null</code>.
+     * @since 4.4.5
+     */
+    public XmlElement getElement() {
+        return element;
+    }
+
     @Override
     public XmlStringBuilder toXML(XmlEnvironment enclosingXmlEnvironment) {
         XmlStringBuilder xml = new XmlStringBuilder(this, enclosingXmlEnvironment);
         xml.rightAngleBracket();
 
         xml.emptyElement(reason);
+        xml.optElement(TEXT_ELEMENT, text);
+        xml.optAppend(element);
 
         xml.closeElement(this);
         return xml;
@@ -142,7 +173,11 @@ public class JingleReason implements XmlElement {
         private final String sessionId;
 
         public AlternativeSession(String sessionId) {
-            super(Reason.alternative_session);
+            this(sessionId, null, null);
+        }
+
+        public AlternativeSession(String sessionId, String text, XmlElement element) {
+            super(Reason.alternative_session, text, element);
             if (StringUtils.isNullOrEmpty(sessionId)) {
                 throw new NullPointerException("SessionID must not be null or empty.");
             }

smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/provider/JingleProvider.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2017-2019 Florian Schmaus
+ * Copyright 2017-2022 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,11 +19,14 @@ package org.jivesoftware.smackx.jingle.provider;
 import java.io.IOException;
 import java.util.logging.Logger;
 
+import org.jivesoftware.smack.packet.IqData;
 import org.jivesoftware.smack.packet.StandardExtensionElement;
+import org.jivesoftware.smack.packet.XmlElement;
 import org.jivesoftware.smack.packet.XmlEnvironment;
 import org.jivesoftware.smack.parsing.SmackParsingException;
 import org.jivesoftware.smack.parsing.StandardExtensionElementProvider;
-import org.jivesoftware.smack.provider.IQProvider;
+import org.jivesoftware.smack.provider.IqProvider;
+import org.jivesoftware.smack.util.PacketParserUtils;
 import org.jivesoftware.smack.util.ParserUtils;
 import org.jivesoftware.smack.xml.XmlPullParser;
 import org.jivesoftware.smack.xml.XmlPullParserException;
@@ -40,13 +43,13 @@ import org.jivesoftware.smackx.jingle.element.UnknownJingleContentTransport;
 
 import org.jxmpp.jid.FullJid;
 
-public class JingleProvider extends IQProvider<Jingle> {
+public class JingleProvider extends IqProvider<Jingle> {
 
     private static final Logger LOGGER = Logger.getLogger(JingleProvider.class.getName());
 
     @Override
-    public Jingle parse(XmlPullParser parser, int initialDepth, XmlEnvironment xmlEnvironment) throws XmlPullParserException, IOException, SmackParsingException {
-        Jingle.Builder builder = Jingle.getBuilder();
+    public Jingle parse(XmlPullParser parser, int initialDepth, IqData iqData, XmlEnvironment xmlEnvironment) throws XmlPullParserException, IOException, SmackParsingException {
+        Jingle.Builder builder = Jingle.builder(iqData);
 
         String actionString = parser.getAttributeValue("", Jingle.ACTION_ATTRIBUTE_NAME);
         if (actionString != null) {
@@ -75,16 +78,7 @@ public class JingleProvider extends IQProvider<Jingle> {
                     builder.addJingleContent(content);
                     break;
                 case JingleReason.ELEMENT:
-                    parser.next();
-                    String reasonString = parser.getName();
-                    JingleReason reason;
-                    if (reasonString.equals("alternative-session")) {
-                        parser.next();
-                        String sid = parser.nextText();
-                        reason = new JingleReason.AlternativeSession(sid);
-                    } else {
-                        reason = new JingleReason(Reason.fromString(reasonString));
-                    }
+                    JingleReason reason = parseJingleReason(parser);
                     builder.setReason(reason);
                     break;
                 default:
@@ -177,4 +171,57 @@ public class JingleProvider extends IQProvider<Jingle> {
 
         return builder.build();
     }
+
+    public static JingleReason parseJingleReason(XmlPullParser parser)
+                    throws XmlPullParserException, IOException, SmackParsingException {
+        ParserUtils.assertAtStartTag(parser);
+        final int initialDepth = parser.getDepth();
+        final String jingleNamespace = parser.getNamespace();
+
+        JingleReason.Reason reason = null;
+        XmlElement element = null;
+        String text = null;
+
+        // 'sid' is only set if the reason is 'alternative-session'.
+        String sid = null;
+
+        outerloop: while (true) {
+            XmlPullParser.TagEvent event = parser.nextTag();
+            switch (event) {
+            case START_ELEMENT:
+                String elementName = parser.getName();
+                String namespace = parser.getNamespace();
+                if (namespace.equals(jingleNamespace)) {
+                    switch (elementName) {
+                    case "text":
+                        text = parser.nextText();
+                        break;
+                    case "alternative-session":
+                        parser.next();
+                        sid = parser.nextText();
+                        break;
+                    default:
+                        reason = Reason.fromString(elementName);
+                        break;
+                    }
+                } else {
+                    element = PacketParserUtils.parseExtensionElement(elementName, namespace, parser, null);
+                }
+                break;
+            case END_ELEMENT:
+                if (parser.getDepth() == initialDepth) {
+                    break outerloop;
+                }
+                break;
+            }
+        }
+
+        JingleReason res;
+        if (sid != null) {
+            res = new JingleReason.AlternativeSession(sid, text, element);
+        } else {
+            res = new JingleReason(reason, text, element);
+        }
+        return res;
+    }
 }

smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/transports/JingleTransportManager.java

@@ -36,6 +36,10 @@ public abstract class JingleTransportManager<D extends JingleContentTransport> i
     }
 
     public XMPPConnection getConnection() {
+        return connection();
+    }
+
+    public XMPPConnection connection() {
         return connection;
     }
 

smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/transports/jingle_s5b/JingleS5BTransportManager.java

@@ -148,7 +148,7 @@ public final class JingleS5BTransportManager extends JingleTransportManager<Jing
     public Jingle createCandidateUsed(FullJid recipient, FullJid initiator, String sessionId, JingleContent.Senders contentSenders,
                                       JingleContent.Creator contentCreator, String contentName, String streamId,
                                       String candidateId) {
-        Jingle.Builder jb = Jingle.getBuilder();
+        Jingle.Builder jb = Jingle.builder(connection());
         jb.setSessionId(sessionId).setInitiator(initiator).setAction(JingleAction.transport_info);
 
         JingleContent.Builder cb = JingleContent.getBuilder();
@@ -165,7 +165,7 @@ public final class JingleS5BTransportManager extends JingleTransportManager<Jing
     }
 
     public Jingle createCandidateError(FullJid remote, FullJid initiator, String sessionId, JingleContent.Senders senders, JingleContent.Creator creator, String name, String streamId) {
-        Jingle.Builder jb = Jingle.getBuilder();
+        Jingle.Builder jb = Jingle.builder(connection());
         jb.setSessionId(sessionId).setInitiator(initiator).setAction(JingleAction.transport_info);
 
         JingleContent.Builder cb = JingleContent.getBuilder();
@@ -184,7 +184,7 @@ public final class JingleS5BTransportManager extends JingleTransportManager<Jing
     public Jingle createProxyError(FullJid remote, FullJid initiator, String sessionId,
                                    JingleContent.Senders senders, JingleContent.Creator creator,
                                    String name, String streamId) {
-        Jingle.Builder jb = Jingle.getBuilder();
+        Jingle.Builder jb = Jingle.builder(connection());
         jb.setSessionId(sessionId).setAction(JingleAction.transport_info).setInitiator(initiator);
 
         JingleContent.Builder cb = JingleContent.getBuilder();
@@ -202,7 +202,7 @@ public final class JingleS5BTransportManager extends JingleTransportManager<Jing
     public Jingle createCandidateActivated(FullJid remote, FullJid initiator, String sessionId,
                                            JingleContent.Senders senders, JingleContent.Creator creator,
                                            String name, String streamId, String candidateId) {
-        Jingle.Builder jb = Jingle.getBuilder();
+        Jingle.Builder jb = Jingle.builder(connection());
         jb.setInitiator(initiator).setSessionId(sessionId).setAction(JingleAction.transport_info);
 
         JingleContent.Builder cb = JingleContent.getBuilder();

smack-extensions/src/main/java/org/jivesoftware/smackx/jiveproperties/provider/JivePropertiesExtensionProvider.java

@@ -26,6 +26,7 @@ import java.util.logging.Logger;
 
 import org.jivesoftware.smack.packet.XmlEnvironment;
 import org.jivesoftware.smack.provider.ExtensionElementProvider;
+import org.jivesoftware.smack.util.DoOnce;
 import org.jivesoftware.smack.util.stringencoder.Base64;
 import org.jivesoftware.smack.xml.XmlPullParser;
 import org.jivesoftware.smack.xml.XmlPullParserException;
@@ -35,6 +36,8 @@ import org.jivesoftware.smackx.jiveproperties.packet.JivePropertiesExtension;
 
 public class JivePropertiesExtensionProvider extends ExtensionElementProvider<JivePropertiesExtension> {
 
+    private static final DoOnce LOG_OBJECT_NOT_ENABLED = new DoOnce();
+
     private static final Logger LOGGER = Logger.getLogger(JivePropertiesExtensionProvider.class.getName());
 
     /**
@@ -113,7 +116,10 @@ public class JivePropertiesExtensionProvider extends ExtensionElementProvider<Ji
                                     }
                                 }
                                 else {
-                                    LOGGER.severe("JavaObject is not enabled. Enable with JivePropertiesManager.setJavaObjectEnabled(true)");
+                                    LOG_OBJECT_NOT_ENABLED.once(
+                                        () -> LOGGER.severe(
+                                            "JavaObject is not enabled. Enable with JivePropertiesManager.setJavaObjectEnabled(true)")
+                                    );
                                 }
                             }
                             if (name != null && value != null) {

smack-extensions/src/main/java/org/jivesoftware/smackx/muc/MucConfigFormManager.java

@@ -78,6 +78,17 @@ public class MucConfigFormManager {
      */
     public static final String MUC_ROOMCONFIG_ROOMSECRET = "muc#roomconfig_roomsecret";
 
+    /**
+     * The constant String {@value}.
+     */
+    public static final String MUC_ROOMCONFIG_MODERATEDROOM = "muc#roomconfig_moderatedroom";
+
+    /**
+     * The constant String {@value}.
+     */
+    public static final String MUC_ROOMCONFIG_PUBLICLYSEARCHABLEROOM = "muc#roomconfig_publicroom";
+
+
     private final MultiUserChat multiUserChat;
     private final FillableForm answerForm;
     private final List<Jid> owners;
@@ -151,6 +162,15 @@ public class MucConfigFormManager {
         return answerForm.hasField(MUC_ROOMCONFIG_MEMBERSONLY);
     }
 
+    /**
+     * Check if the room supports being moderated in the configuration.
+     *
+     * @return <code>true</code> if supported, <code>false</code> if not.
+     */
+    public boolean supportsModeration() {
+        return answerForm.hasField(MUC_ROOMCONFIG_MODERATEDROOM);
+    }
+
     /**
      * Make the room for members only.
      *
@@ -176,6 +196,68 @@ public class MucConfigFormManager {
         return this;
     }
 
+
+    /**
+     * Make the room moderated.
+     *
+     * @return a reference to this object.
+     * @throws MucConfigurationNotSupportedException if the requested MUC configuration is not supported by the MUC service.
+     */
+    public MucConfigFormManager makeModerated() throws MucConfigurationNotSupportedException {
+        return setModerated(true);
+    }
+
+    /**
+     * Set if the room is members only. Rooms are not members only per default.
+     *
+     * @param isModerated if the room should be moderated.
+     * @return a reference to this object.
+     * @throws MucConfigurationNotSupportedException if the requested MUC configuration is not supported by the MUC service.
+     */
+    public MucConfigFormManager setModerated(boolean isModerated) throws MucConfigurationNotSupportedException {
+        if (!supportsModeration()) {
+            throw new MucConfigurationNotSupportedException(MUC_ROOMCONFIG_MODERATEDROOM);
+        }
+        answerForm.setAnswer(MUC_ROOMCONFIG_MODERATEDROOM, isModerated);
+        return this;
+    }
+
+
+    /**
+     * Make the room publicly searchable.
+     *
+     * @return a reference to this object.
+     * @throws MucConfigurationNotSupportedException if the requested MUC configuration is not supported by the MUC service.
+     */
+    public MucConfigFormManager makePublic() throws MucConfigurationNotSupportedException {
+        return setPublic(true);
+    }
+
+    /**
+     * Make the room hidden (not publicly searchable).
+     *
+     * @return a reference to this object.
+     * @throws MucConfigurationNotSupportedException if the requested MUC configuration is not supported by the MUC service.
+     */
+    public MucConfigFormManager makeHidden() throws MucConfigurationNotSupportedException {
+        return setPublic(false);
+    }
+
+    /**
+     * Set if the room is publicly searchable (i.e. visible via discovery requests to the MUC service).
+     *
+     * @param isPublic if the room should be publicly searchable.
+     * @return a reference to this object.
+     * @throws MucConfigurationNotSupportedException if the requested MUC configuration is not supported by the MUC service.
+     */
+    public MucConfigFormManager setPublic(boolean isPublic) throws MucConfigurationNotSupportedException {
+        if (!supportsModeration()) {
+            throw new MucConfigurationNotSupportedException(MUC_ROOMCONFIG_PUBLICLYSEARCHABLEROOM);
+        }
+        answerForm.setAnswer(MUC_ROOMCONFIG_PUBLICLYSEARCHABLEROOM, isPublic);
+        return this;
+    }
+
     /**
      * Check if the room supports password protection.
      *

smack-extensions/src/main/java/org/jivesoftware/smackx/muc/MultiUserChat.java

@@ -205,12 +205,20 @@ public class MultiUserChat {
                 if (from == null) {
                     return;
                 }
-                final EntityFullJid myRoomJID = myRoomJid;
+                final EntityFullJid myRoomJID = getMyRoomJid();
                 final boolean isUserStatusModification = presence.getFrom().equals(myRoomJID);
                 final MUCUser mucUser = MUCUser.from(packet);
 
                 switch (presence.getType()) {
                 case available:
+                    if (!processedReflectedSelfPresence
+                                    && mucUser.getStatus().contains(MUCUser.Status.PRESENCE_TO_SELF_110)) {
+                        processedReflectedSelfPresence = true;
+                        synchronized (this) {
+                            notify();
+                        }
+                    }
+
                     Presence oldPresence = occupantsMap.put(from, presence);
                     if (oldPresence != null) {
                         // Get the previous occupant's affiliation & role
@@ -228,11 +236,6 @@ public class MultiUserChat {
                             newAffiliation,
                             isUserStatusModification,
                             from);
-                    } else if (mucUser.getStatus().contains(MUCUser.Status.PRESENCE_TO_SELF_110)) {
-                        processedReflectedSelfPresence = true;
-                        synchronized (this) {
-                            notify();
-                        }
                     } else {
                         // A new occupant has joined the room
                         for (ParticipantStatusListener listener : participantStatusListeners) {
@@ -259,6 +262,7 @@ public class MultiUserChat {
                                 listener.left(from);
                             }
                         }
+                    }
 
                     Destroy destroy = mucUser.getDestroy();
                     // The room has been destroyed.
@@ -275,7 +279,7 @@ public class MultiUserChat {
                             listener.roomDestroyed(alternateMuc, destroy.getReason());
                         }
                     }
-                    }
+
                     if (isUserStatusModification) {
                         for (UserStatusListener listener : userStatusListeners) {
                             listener.removed(mucUser, presence);
@@ -728,7 +732,7 @@ public class MultiUserChat {
      * @return true if currently in the multi user chat room.
      */
     public boolean isJoined() {
-        return myRoomJid != null;
+        return getMyRoomJid() != null;
     }
 
     /**
@@ -764,7 +768,7 @@ public class MultiUserChat {
         // "if  (!joined) return" because it should be always be possible to leave the room in case the instance's
         // state does not reflect the actual state.
 
-        final EntityFullJid myRoomJid = this.myRoomJid;
+        final EntityFullJid myRoomJid = getMyRoomJid();
         if (myRoomJid == null) {
             throw new MucNotJoinedException(this);
         }
@@ -793,11 +797,14 @@ public class MultiUserChat {
 
         StanzaFilter reflectedLeavePresenceFilter = new AndFilter(reflectedLeavePresenceFilters);
 
-        // Reset occupant information first so that we are assume that we left the room even if sendStanza() would
-        // throw.
+        Presence reflectedLeavePresence;
+        try {
+            reflectedLeavePresence = connection.createStanzaCollectorAndSend(reflectedLeavePresenceFilter, leavePresence).nextResultOrThrow();
+        } finally {
+            // Reset occupant information after we send the leave presence. This ensures that we only call userHasLeft()
+            // and reset the local MUC state after we successfully left the MUC (or if an exception occurred).
             userHasLeft();
-
-        Presence reflectedLeavePresence = connection.createStanzaCollectorAndSend(reflectedLeavePresenceFilter, leavePresence).nextResultOrThrow();
+        }
 
         return reflectedLeavePresence;
     }
@@ -1193,13 +1200,23 @@ public class MultiUserChat {
      * @return the nickname currently being used.
      */
     public Resourcepart getNickname() {
-        final EntityFullJid myRoomJid = this.myRoomJid;
+        final EntityFullJid myRoomJid = getMyRoomJid();
         if (myRoomJid == null) {
             return null;
         }
         return myRoomJid.getResourcepart();
     }
 
+    /**
+     * Return the full JID of the user in the room, or <code>null</code> if the room is not joined.
+     *
+     * @return the full JID of the user in the room, or <code>null</code>.
+     * @since 4.5.0
+     */
+    public EntityFullJid getMyRoomJid() {
+        return myRoomJid;
+    }
+
     /**
      * Changes the occupant's nickname to a new nickname within the room. Each room occupant
      * will receive two presence packets. One of type "unavailable" for the old nickname and one
@@ -1256,7 +1273,7 @@ public class MultiUserChat {
      * @throws MucNotJoinedException if not joined to the Multi-User Chat.
      */
     public void changeAvailabilityStatus(String status, Presence.Mode mode) throws NotConnectedException, InterruptedException, MucNotJoinedException {
-        final EntityFullJid myRoomJid = this.myRoomJid;
+        final EntityFullJid myRoomJid = getMyRoomJid();
         if (myRoomJid == null) {
             throw new MucNotJoinedException(this);
         }
@@ -2579,7 +2596,7 @@ public class MultiUserChat {
     }
 
     public boolean serviceSupportsStableIds() {
-        return mucServiceDiscoInfo.containsFeature(MultiUserChatConstants.STABLE_ID_FEATURE);
+        return DiscoverInfo.nullSafeContainsFeature(mucServiceDiscoInfo, MultiUserChatConstants.STABLE_ID_FEATURE);
     }
 
     @Override

smack-extensions/src/main/java/org/jivesoftware/smackx/pubsub/FormNode.java

@@ -38,11 +38,7 @@ public class FormNode extends NodeExtension {
      * @param submitForm The form
      */
     public FormNode(FormNodeType formType, DataForm submitForm) {
-        super(formType.getNodeElement());
-
-        if (submitForm == null)
-            throw new IllegalArgumentException("Submit form cannot be null");
-        configForm = submitForm;
+        this(formType, null, submitForm);
     }
 
     /**
@@ -55,9 +51,6 @@ public class FormNode extends NodeExtension {
      */
     public FormNode(FormNodeType formType, String nodeId, DataForm submitForm) {
         super(formType.getNodeElement(), nodeId);
-
-        if (submitForm == null)
-            throw new IllegalArgumentException("Submit form cannot be null");
         configForm = submitForm;
     }
 

smack-extensions/src/main/java/org/jivesoftware/smackx/pubsub/provider/FormNodeProvider.java

@@ -35,6 +35,11 @@ import org.jivesoftware.smackx.xdata.packet.DataForm;
 public class FormNodeProvider extends EmbeddedExtensionProvider<FormNode> {
     @Override
     protected FormNode createReturnExtension(String currentElement, String currentNamespace, Map<String, String> attributeMap, List<? extends XmlElement> content) {
-        return new FormNode(FormNodeType.valueOfFromElementName(currentElement, currentNamespace), attributeMap.get("node"), (DataForm) content.iterator().next());
+        DataForm dataForm = null;
+        if (!content.isEmpty()) {
+            dataForm = (DataForm) content.get(0);
+        }
+
+        return new FormNode(FormNodeType.valueOfFromElementName(currentElement, currentNamespace), attributeMap.get("node"), dataForm);
     }
 }

smack-extensions/src/main/java/org/jivesoftware/smackx/pubsub/provider/ItemProvider.java

@@ -50,12 +50,9 @@ public class ItemProvider extends ExtensionElementProvider<Item>  {
         String xmlns = parser.getNamespace();
         ItemNamespace itemNamespace = ItemNamespace.fromXmlns(xmlns);
 
-        XmlPullParser.Event tag = parser.next();
-
-        if (tag == XmlPullParser.Event.END_ELEMENT)  {
-            return new Item(itemNamespace, id, node);
-        }
-        else {
+        XmlPullParser.TagEvent event = parser.nextTag();
+        switch (event) {
+            case START_ELEMENT:
                 String payloadElemName = parser.getName();
                 String payloadNS = parser.getNamespace();
 
@@ -68,6 +65,10 @@ public class ItemProvider extends ExtensionElementProvider<Item>  {
                 else {
                     return new PayloadItem<>(itemNamespace, id, node, extensionProvider.parse(parser));
                 }
+            case END_ELEMENT:
+                return new Item(itemNamespace, id, node);
+            default:
+                throw new AssertionError("unknown: " + event);
         }
     }
 

smack-extensions/src/main/java/org/jivesoftware/smackx/softwareinfo/form/SoftwareInfoForm.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2020 Aditya Borikar
+ * Copyright 2020 Aditya Borikar, 2021 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,7 +20,7 @@ import java.util.List;
 
 import org.jivesoftware.smack.util.EqualsUtil;
 import org.jivesoftware.smack.util.HashCode;
-
+import org.jivesoftware.smackx.formtypes.FormFieldRegistry;
 import org.jivesoftware.smackx.mediaelement.element.MediaElement;
 import org.jivesoftware.smackx.xdata.FormField;
 import org.jivesoftware.smackx.xdata.FormFieldChildElement;
@@ -47,6 +47,11 @@ public final class SoftwareInfoForm extends FilledForm {
     public static final String SOFTWARE_VERSION = "software_version";
     public static final String ICON = "icon";
 
+    static {
+        FormFieldRegistry.register(FORM_TYPE, FormField.Type.text_single,
+                        OS, OS_VERSION, SOFTWARE, SOFTWARE_VERSION);
+    }
+
     private SoftwareInfoForm(DataForm dataForm) {
         super(dataForm);
     }

smack-extensions/src/main/java/org/jivesoftware/smackx/xdata/AbstractMultiFormField.java

@@ -27,35 +27,26 @@ import org.jxmpp.util.XmppDateTime;
 
 public class AbstractMultiFormField extends FormField {
 
-    private final List<String> values;
-
-    private final List<String> rawValues;
+    private final List<Value> values;
 
     protected AbstractMultiFormField(Builder<?, ?> builder) {
         super(builder);
         values = CollectionUtil.cloneAndSeal(builder.values);
-        rawValues = CollectionUtil.cloneAndSeal(builder.rawValues);
     }
 
     @Override
-    public final List<String> getValues() {
+    public final List<Value> getRawValues() {
         return values;
     }
 
-    @Override
-    public final List<String> getRawValues() {
-        return rawValues;
-    }
-
     public abstract static class Builder<F extends AbstractMultiFormField, B extends FormField.Builder<F, B>>
                     extends FormField.Builder<F, B> {
 
-        private List<String> values;
-        private List<String> rawValues;
+        private List<Value> values;
 
         protected Builder(AbstractMultiFormField formField) {
             super(formField);
-            values = CollectionUtil.newListWith(formField.getValues());
+            values = CollectionUtil.newListWith(formField.getRawValues());
         }
 
         protected Builder(String fieldName, FormField.Type type) {
@@ -65,7 +56,6 @@ public class AbstractMultiFormField extends FormField {
         private void ensureValuesAreInitialized() {
             if (values == null) {
                 values = new ArrayList<>();
-                rawValues = new ArrayList<>();
             }
         }
 
@@ -77,11 +67,13 @@ public class AbstractMultiFormField extends FormField {
         public abstract B addValue(CharSequence value);
 
         public B addValueVerbatim(CharSequence value) {
+            return addValueVerbatim(new Value(value));
+        }
+
+        public B addValueVerbatim(Value value) {
             ensureValuesAreInitialized();
 
-            String valueString = value.toString();
-            values.add(valueString);
-            rawValues.add(valueString);
+            values.add(value);
             return getThis();
         }
 

smack-extensions/src/main/java/org/jivesoftware/smackx/xdata/AbstractSingleStringValueFormField.java

@@ -74,8 +74,15 @@ public class AbstractSingleStringValueFormField extends SingleValueFormField {
             return setValue(value);
         }
 
+        public B setValue(Value value) {
+            this.value = value.getValue().toString();
+            this.rawValue = value;
+            return getThis();
+        }
+
         public B setValue(CharSequence value) {
-            this.rawValue = this.value = value.toString();
+            this.value = value.toString();
+            rawValue = new Value(this.value);
             return getThis();
         }
 

smack-extensions/src/main/java/org/jivesoftware/smackx/xdata/BooleanFormField.java

@@ -35,7 +35,31 @@ public class BooleanFormField extends SingleValueFormField {
         return value.toString();
     }
 
-    public Boolean getValueAsBoolean() {
+    /**
+     * Get the value of the booelan field. Note that, if no explicit boolean value is provided, in the form of "true",
+     * "false", "0", or "1", then the default value of a boolean field is <code>false</code>, according to
+     * XEP-0004 § 3.3.
+     *
+     * @return the boolean value of this form field.
+     */
+    public boolean getValueAsBoolean() {
+        if (value == null) {
+            return false;
+        }
+        return value;
+    }
+
+    /**
+     * Get the value of the boolean field or maybe <code>null</code>. Note that you usually want to use
+     * {@link #getValueAsBoolean()} instead of this method, as {@link #getValueAsBoolean()} considers the default value
+     * of boolean fields. That is, boolean form fields have the value <code>false</code> if not explicitly set to
+     * something else.
+     *
+     * @return the boolean value of this form field or <code>null</code> if no value was explicitly provided.
+     * @see #getValueAsBoolean()
+     * @since 4.4.5
+     */
+    public Boolean getValueAsBooleanOrNull() {
         return value;
     }
 
@@ -71,17 +95,21 @@ public class BooleanFormField extends SingleValueFormField {
         @Deprecated
         // TODO: Remove in Smack 4.6.
         public Builder addValue(CharSequence value) {
-            return setValue(value);
+            return setValue(new Value(value));
         }
 
         public Builder setValue(CharSequence value) {
-            rawValue = value.toString();
-            boolean valueBoolean = ParserUtils.parseXmlBoolean(rawValue);
-            return setValue(valueBoolean);
+            return setValue(new Value(value));
+        }
+
+        public Builder setValue(Value value) {
+            this.value = ParserUtils.parseXmlBoolean(value.getValue().toString());
+            rawValue = value;
+            return getThis();
         }
 
         public Builder setValue(boolean value) {
-            rawValue = Boolean.toString(value);
+            rawValue = new Value(Boolean.toString(value));
             this.value = value;
             return this;
         }

smack-extensions/src/main/java/org/jivesoftware/smackx/xdata/FormField.java

@@ -33,6 +33,7 @@ import org.jivesoftware.smack.util.CollectionUtil;
 import org.jivesoftware.smack.util.EqualsUtil;
 import org.jivesoftware.smack.util.HashCode;
 import org.jivesoftware.smack.util.MultiMap;
+import org.jivesoftware.smack.util.Objects;
 import org.jivesoftware.smack.util.StringUtils;
 import org.jivesoftware.smack.util.XmlStringBuilder;
 
@@ -269,9 +270,25 @@ public abstract class FormField implements XmlElement {
      *
      * @return a List of the default values or answered values of the question.
      */
-    public abstract List<? extends CharSequence> getValues();
+    public List<? extends CharSequence> getValues() {
+        return getRawValueCharSequences();
+    }
 
-    public abstract List<String> getRawValues();
+    public abstract List<Value> getRawValues();
+
+    private transient List<CharSequence> rawValueCharSequences;
+
+    public final List<CharSequence> getRawValueCharSequences() {
+        if (rawValueCharSequences == null) {
+            List<Value> rawValues = getRawValues();
+            rawValueCharSequences = new ArrayList<>(rawValues.size());
+            for (Value value : rawValues) {
+                rawValueCharSequences.add(value.value);
+            }
+        }
+
+        return rawValueCharSequences;
+    }
 
     public boolean hasValueSet() {
         List<?> values = getValues();
@@ -385,12 +402,15 @@ public abstract class FormField implements XmlElement {
 
     protected transient List<XmlElement> extraXmlChildElements;
 
+    /**
+     * Populate @{link {@link #extraXmlChildElements}}. Note that this method may be overridden by subclasses.
+     */
     protected void populateExtraXmlChildElements() {
-        List<? extends CharSequence> values = getValues();
+        List<Value> values = getRawValues();
+        // Note that we need to create a new ArrayList here, since subclasses may add to it by overriding
+        // populateExtraXmlChildElements.
         extraXmlChildElements = new ArrayList<>(values.size());
-        for (CharSequence value : values) {
-            extraXmlChildElements.add(new Value(value));
-        }
+        extraXmlChildElements.addAll(values);
     }
 
     @Override
@@ -414,7 +434,8 @@ public abstract class FormField implements XmlElement {
             populateExtraXmlChildElements();
         }
 
-        if (formFieldChildElements.isEmpty() && extraXmlChildElements == null) {
+        if (formFieldChildElements.isEmpty()
+                        && (extraXmlChildElements == null || extraXmlChildElements.isEmpty())) {
             buf.closeEmptyElement();
         } else {
             buf.rightAngleBracket();
@@ -580,7 +601,7 @@ public abstract class FormField implements XmlElement {
          * @return a reference to this builder.
          */
         public B setLabel(String label) {
-            this.label = StringUtils.requireNotNullNorEmpty(label, "label must not be null or empty");
+            this.label = Objects.requireNonNull(label, "label must not be null");
             return getThis();
         }
 

smack-extensions/src/main/java/org/jivesoftware/smackx/xdata/JidMultiFormField.java

@@ -23,13 +23,14 @@ import java.util.List;
 import org.jivesoftware.smack.util.CollectionUtil;
 
 import org.jxmpp.jid.Jid;
-import org.jxmpp.jid.util.JidUtil;
+import org.jxmpp.jid.impl.JidCreate;
+import org.jxmpp.stringprep.XmppStringprepException;
 
 public final class JidMultiFormField extends FormField {
 
     private final List<Jid> values;
 
-    private final List<String> rawValues;
+    private final List<Value> rawValues;
 
     JidMultiFormField(Builder builder) {
         super(builder);
@@ -43,7 +44,7 @@ public final class JidMultiFormField extends FormField {
     }
 
     @Override
-    public List<String> getRawValues() {
+    public List<Value> getRawValues() {
         return rawValues;
     }
 
@@ -54,7 +55,7 @@ public final class JidMultiFormField extends FormField {
     public static final class Builder extends FormField.Builder<JidMultiFormField, JidMultiFormField.Builder> {
         private List<Jid> values;
 
-        private List<String> rawValues;
+        private List<Value> rawValues;
 
         private Builder(JidMultiFormField jidMultiFormField) {
             super(jidMultiFormField);
@@ -79,27 +80,29 @@ public final class JidMultiFormField extends FormField {
         }
 
         public Builder addValue(Jid jid) {
-            return addValue(jid, null);
-        }
-
-        public Builder addValue(Jid jid, String rawValue) {
-            if (rawValue == null) {
-                rawValue = jid.toString();
-            }
+            Value value = new Value(jid);
 
             ensureValuesAreInitialized();
-
             values.add(jid);
-            rawValues.add(rawValue);
+            rawValues.add(value);
+
+            return getThis();
+        }
+
+        public Builder addValue(Value value) throws XmppStringprepException {
+            Jid jid = JidCreate.from(value.getValue());
+
+            ensureValuesAreInitialized();
+            values.add(jid);
+            rawValues.add(value);
 
             return this;
         }
 
         public Builder addValues(Collection<? extends Jid> jids) {
-            ensureValuesAreInitialized();
-
-            values.addAll(jids);
-            rawValues.addAll(JidUtil.toStringList(jids));
+            for (Jid jid : jids) {
+                addValue(jid);
+            }
             return this;
         }
 

smack-extensions/src/main/java/org/jivesoftware/smackx/xdata/JidSingleFormField.java

@@ -17,6 +17,8 @@
 package org.jivesoftware.smackx.xdata;
 
 import org.jxmpp.jid.Jid;
+import org.jxmpp.jid.impl.JidCreate;
+import org.jxmpp.stringprep.XmppStringprepException;
 
 public class JidSingleFormField extends SingleValueFormField {
 
@@ -60,11 +62,13 @@ public class JidSingleFormField extends SingleValueFormField {
 
         public Builder setValue(Jid value, String rawValue) {
             this.value = value;
-            if (rawValue != null) {
-                this.rawValue = rawValue;
-            } else {
-                this.rawValue = value.toString();
+            this.rawValue = new Value(value);
+            return getThis();
         }
+
+        public Builder setValue(Value value) throws XmppStringprepException {
+            this.value = JidCreate.from(value.getValue());
+            this.rawValue = value;
             return this;
         }
 

smack-extensions/src/main/java/org/jivesoftware/smackx/xdata/SingleValueFormField.java

@@ -23,7 +23,7 @@ import org.jivesoftware.smack.util.CollectionUtil;
 
 public abstract class SingleValueFormField extends FormField {
 
-    private final String rawValue;
+    private final Value rawValue;
 
     protected SingleValueFormField(Builder<?, ?> builder) {
         super(builder);
@@ -38,24 +38,23 @@ public abstract class SingleValueFormField extends FormField {
 
     public abstract CharSequence getValue();
 
-    public final String getRawValue() {
+    public final Value getRawValue() {
         return rawValue;
     }
 
     @Override
-    public final List<String> getRawValues() {
-        String rawValue = getRawValue();
+    public final List<Value> getRawValues() {
+        Value rawValue = getRawValue();
         return CollectionUtil.emptyOrSingletonListFrom(rawValue);
     }
 
     @Override
     protected void populateExtraXmlChildElements() {
-        CharSequence value = getValue();
-        if (value == null) {
+        if (rawValue == null) {
             return;
         }
 
-        extraXmlChildElements = Collections.singletonList(new Value(value));
+        extraXmlChildElements = Collections.singletonList(rawValue);
     }
 
     public abstract static class Builder<F extends SingleValueFormField, B extends Builder<F, B>>
@@ -65,11 +64,12 @@ public abstract class SingleValueFormField extends FormField {
             super(fieldName, type);
         }
 
-        protected Builder(FormField formField) {
+        protected Builder(SingleValueFormField formField) {
             super(formField);
+            rawValue = formField.getRawValue();
         }
 
-        protected String rawValue;
+        protected Value rawValue;
 
         @Override
         protected void resetInternal() {

smack-extensions/src/main/java/org/jivesoftware/smackx/xdata/form/FormReader.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2020 Florian Schmaus
+ * Copyright 2020-2021 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,6 +21,8 @@ import java.util.Collections;
 import java.util.Date;
 import java.util.List;
 
+import org.jivesoftware.smack.util.StringUtils;
+
 import org.jivesoftware.smackx.xdata.AbstractMultiFormField;
 import org.jivesoftware.smackx.xdata.AbstractSingleStringValueFormField;
 import org.jivesoftware.smackx.xdata.BooleanFormField;
@@ -54,7 +56,8 @@ public interface FormReader {
             return Collections.emptyList();
         }
         AbstractMultiFormField multiFormField = formField.ifPossibleAs(AbstractMultiFormField.class);
-        return multiFormField.getValues();
+        List<? extends CharSequence> charSequences =  multiFormField.getValues();
+        return StringUtils.toStrings(charSequences);
     }
 
     default Boolean readBoolean(String fieldName) {

smack-extensions/src/main/java/org/jivesoftware/smackx/xdata/provider/DataFormProvider.java

@@ -49,9 +49,6 @@ import org.jivesoftware.smackx.xdata.packet.DataForm;
 import org.jivesoftware.smackx.xdatalayout.packet.DataLayout;
 import org.jivesoftware.smackx.xdatalayout.provider.DataLayoutProvider;
 
-import org.jxmpp.jid.Jid;
-import org.jxmpp.jid.impl.JidCreate;
-
 /**
  * The DataFormProvider parses DataForm packets.
  *
@@ -237,9 +234,7 @@ public class DataFormProvider extends ExtensionElementProvider<DataForm> {
         case jid_multi:
             JidMultiFormField.Builder jidMultiBuilder = FormField.jidMultiBuilder(fieldName);
             for (FormField.Value value : values) {
-                String rawValue = value.getValue().toString();
-                Jid jid = JidCreate.from(rawValue);
-                jidMultiBuilder.addValue(jid, rawValue);
+                jidMultiBuilder.addValue(value);
             }
             builder = jidMultiBuilder;
             break;
@@ -247,9 +242,8 @@ public class DataFormProvider extends ExtensionElementProvider<DataForm> {
             ensureAtMostSingleValue(type, values);
             JidSingleFormField.Builder jidSingleBuilder = FormField.jidSingleBuilder(fieldName);
             if (!values.isEmpty()) {
-                String rawValue = values.get(0).getValue().toString();
-                Jid jid = JidCreate.from(rawValue);
-                jidSingleBuilder.setValue(jid, rawValue);
+                FormField.Value value = values.get(0);
+                jidSingleBuilder.setValue(value);
             }
             builder = jidSingleBuilder;
             break;
@@ -303,7 +297,7 @@ public class DataFormProvider extends ExtensionElementProvider<DataForm> {
         BooleanFormField.Builder builder = FormField.booleanBuilder(fieldName);
         ensureAtMostSingleValue(builder.getType(), values);
         if (values.size() == 1) {
-            String value = values.get(0).getValue().toString();
+            FormField.Value value = values.get(0);
             builder.setValue(value);
         }
         return builder;

smack-extensions/src/main/resources/org.jivesoftware.smack.extensions/extensions.xml

@@ -20,5 +20,6 @@
 		<className>org.jivesoftware.smackx.receipts.DeliveryReceiptManager</className>
 		<className>org.jivesoftware.smackx.iqversion.VersionManager</className>
 		<className>org.jivesoftware.smackx.caps.EntityCapsManager</className>
+		<className>org.jivesoftware.smackx.softwareinfo.form.SoftwareInfoForm</className>
     </startupClasses>
 </smack>

smack-extensions/src/test/java/org/jivesoftware/smackx/amp/AMPExtensionTest.java

@@ -67,7 +67,6 @@ public class AMPExtensionTest {
         AMPExtensionProvider ampProvider = new AMPExtensionProvider();
         XmlPullParser parser = PacketParserUtils.getParserFor(INCORRECT_RECEIVING_STANZA_STREAM);
 
-        assertEquals(XmlPullParser.Event.START_ELEMENT, parser.next());
         assertEquals(AMPExtension.ELEMENT, parser.getName());
 
         ExtensionElement extension = ampProvider.parse(parser);
@@ -85,7 +84,6 @@ public class AMPExtensionTest {
         AMPExtensionProvider ampProvider = new AMPExtensionProvider();
         XmlPullParser parser = PacketParserUtils.getParserFor(CORRECT_SENDING_STANZA_STREAM);
 
-        assertEquals(XmlPullParser.Event.START_ELEMENT, parser.next());
         assertEquals(AMPExtension.ELEMENT, parser.getName());
         ExtensionElement extension = ampProvider.parse(parser);
         assertTrue(extension instanceof AMPExtension);

smack-extensions/src/test/java/org/jivesoftware/smackx/jingle/JingleContentTest.java

@@ -75,8 +75,7 @@ public class JingleContentTest extends SmackTestSuite {
         assertEquals(content1.toXML().toString(), builder.build().toXML().toString());
 
         String xml =
-                "<content xmlns='urn:xmpp:jingle:1' creator='initiator' disposition='session' name='A name' senders='both'>" +
-                "</content>";
+                "<content xmlns='urn:xmpp:jingle:1' creator='initiator' disposition='session' name='A name' senders='both'/>";
         assertEquals(xml, content1.toXML().toString());
     }
 }

smack-extensions/src/test/java/org/jivesoftware/smackx/jingle/JingleTest.java

@@ -38,7 +38,7 @@ public class JingleTest extends SmackTestSuite {
 
     @Test
     public void emptyBuilderTest() {
-        Jingle.Builder builder = Jingle.getBuilder();
+        Jingle.Builder builder = Jingle.builder("id");
         assertThrows(IllegalArgumentException.class, () -> {
             builder.build();
         });
@@ -48,7 +48,7 @@ public class JingleTest extends SmackTestSuite {
     public void onlySessionIdBuilderTest() {
         String sessionId = "testSessionId";
 
-        Jingle.Builder builder = Jingle.getBuilder();
+        Jingle.Builder builder = Jingle.builder("id");
         builder.setSessionId(sessionId);
         assertThrows(IllegalArgumentException.class, () -> {
             builder.build();
@@ -59,7 +59,7 @@ public class JingleTest extends SmackTestSuite {
     public void parserTest() throws XmppStringprepException {
         String sessionId = "testSessionId";
 
-        Jingle.Builder builder = Jingle.getBuilder();
+        Jingle.Builder builder = Jingle.builder("id");
         builder.setSessionId(sessionId);
         builder.setAction(JingleAction.session_initiate);
 

smack-extensions/src/test/java/org/jivesoftware/smackx/jingle/element/JingleTest.java

@@ -0,0 +1,48 @@
+/**
+ *
+ * Copyright 2021 Florian Schmaus
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smackx.jingle.element;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.jivesoftware.smack.packet.StreamOpen;
+
+import org.junit.jupiter.api.Test;
+
+public class JingleTest {
+
+    @Test
+    public void noRedundantNamespaceTest() {
+        Jingle.Builder jingleBuilder = Jingle.builder("test-id");
+        jingleBuilder.setSessionId("MySession");
+        jingleBuilder.setAction(JingleAction.content_accept);
+
+        JingleContent.Builder jingleContentBuilder = JingleContent.getBuilder();
+        jingleContentBuilder.setName("Hello world");
+        jingleContentBuilder.setCreator(JingleContent.Creator.initiator);
+
+        jingleBuilder.addJingleContent(jingleContentBuilder.build());
+        Jingle iq = jingleBuilder.build();
+
+        String actualXml = iq.toXML(StreamOpen.CLIENT_NAMESPACE).toString();
+        String expectedXml
+                        = "<iq id='test-id' type='set'>"
+                        + "<jingle xmlns='urn:xmpp:jingle:1' action='content-accept' sid='MySession'>"
+                        + "<content creator='initiator' name='Hello world'/>"
+                        + "</jingle></iq>";
+        assertEquals(expectedXml, actualXml);
+    }
+}

smack-extensions/src/test/java/org/jivesoftware/smackx/jingle/provider/JingleProviderTest.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2017 Florian Schmaus
+ * Copyright 2017-2022 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,23 +17,30 @@
 package org.jivesoftware.smackx.jingle.provider;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.io.IOException;
 
-import org.jivesoftware.smack.util.PacketParserUtils;
-import org.jivesoftware.smack.xml.XmlPullParser;
+import org.jivesoftware.smack.packet.StandardExtensionElement;
+import org.jivesoftware.smack.packet.XmlElement;
+import org.jivesoftware.smack.parsing.SmackParsingException;
+import org.jivesoftware.smack.test.util.SmackTestUtil;
 import org.jivesoftware.smack.xml.XmlPullParserException;
 
 import org.jivesoftware.smackx.jingle.element.Jingle;
 import org.jivesoftware.smackx.jingle.element.JingleContentDescription;
 import org.jivesoftware.smackx.jingle.element.JingleContentTransport;
+import org.jivesoftware.smackx.jingle.element.JingleReason;
 
-import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.EnumSource;
 
 public class JingleProviderTest {
 
-    @Test
-    public void testParseUnknownJingleContentDescrption() throws Exception {
+    @ParameterizedTest
+    @EnumSource(SmackTestUtil.XmlPullParserKind.class)
+    public void testParseUnknownJingleContentDescrption(SmackTestUtil.XmlPullParserKind parserKind)
+                    throws XmlPullParserException, IOException, SmackParsingException {
         final String unknownJingleContentDescriptionNamespace = "urn:xmpp:jingle:unknown-description:5";
         final String unknownJingleContentDescription =
                         // @formatter:off
@@ -50,8 +57,8 @@ public class JingleProviderTest {
                           "</file>" +
                         "</description>";
                         // @formatter:on
-        XmlPullParser parser = createTestJingle(unknownJingleContentDescription);
-        Jingle jingle = (Jingle) PacketParserUtils.parseIQ(parser);
+        CharSequence xml = createTestJingle(unknownJingleContentDescription);
+        Jingle jingle = SmackTestUtil.parse(xml, JingleProvider.class, parserKind);
 
         JingleContentDescription jingleContentDescription = jingle.getSoleContentOrThrow().getDescription();
 
@@ -59,8 +66,10 @@ public class JingleProviderTest {
         assertEquals(unknownJingleContentDescriptionNamespace, parsedUnknownJingleContentDescriptionNamespace);
     }
 
-    @Test
-    public void testParseUnknownJingleContentTransport() throws Exception {
+    @ParameterizedTest
+    @EnumSource(SmackTestUtil.XmlPullParserKind.class)
+    public void testParseUnknownJingleContentTransport(SmackTestUtil.XmlPullParserKind parserKind)
+                    throws XmlPullParserException, IOException, SmackParsingException {
         final String unknownJingleContentTransportNamespace = "urn:xmpp:jingle:unknown-transport:foo:1";
         final String unknownJingleContentTransport =
                         // @formatter:off
@@ -81,8 +90,8 @@ public class JingleProviderTest {
                                    " type='direct'/>" +
                         "</transport>";
                         // @formatter:on
-        XmlPullParser parser = createTestJingle(unknownJingleContentTransport);
-        Jingle jingle = (Jingle) PacketParserUtils.parseIQ(parser);
+        CharSequence xml = createTestJingle(unknownJingleContentTransport);
+        Jingle jingle = SmackTestUtil.parse(xml, JingleProvider.class, parserKind);
 
         JingleContentTransport jingleContentTransport = jingle.getSoleContentOrThrow().getTransport();
 
@@ -90,7 +99,38 @@ public class JingleProviderTest {
         assertEquals(unknownJingleContentTransportNamespace, parsedUnknownJingleContentTransportNamespace);
     }
 
-    private static XmlPullParser createTestJingle(String... childs) throws XmlPullParserException, IOException {
+    @ParameterizedTest
+    @EnumSource(SmackTestUtil.XmlPullParserKind.class)
+    public void testReasonElementWithExtraElement(SmackTestUtil.XmlPullParserKind parserKind)
+                    throws XmlPullParserException, IOException, SmackParsingException {
+        String xml = "<iq from='juliet@capulet.lit/balcony'"
+                        +      " id='le71fa63'"
+                        +      " to='romeo@montague.lit/orchard'"
+                        +      " type='set'>"
+                        +    "<jingle xmlns='urn:xmpp:jingle:1'"
+                        +            " action='session-terminate'"
+                        +            " sid='a73sjjvkla37jfea'>"
+                        +      "<reason>"
+                        +        "<success/>"
+                        +        "<my-element xmlns='https://example.org' foo='bar'/>"
+                        +      "</reason>"
+                        +    "</jingle>"
+                        + "</iq>";
+        Jingle jingle = SmackTestUtil.parse(xml, JingleProvider.class, parserKind);
+        JingleReason jingleReason = jingle.getReason();
+
+        assertEquals(JingleReason.Reason.success, jingleReason.asEnum());
+
+        XmlElement element = jingleReason.getElement();
+        // TODO: Use JUnit 5.8's assertInstanceOf when possible
+        // assertInstanceOf(StandardExtesionElement.class, extraElement);
+        assertTrue(element instanceof StandardExtensionElement);
+        StandardExtensionElement extraElement = (StandardExtensionElement) element;
+        assertEquals("https://example.org", extraElement.getNamespace());
+        assertEquals("bar", extraElement.getAttributes().get("foo"));
+    }
+
+    private static CharSequence createTestJingle(String... childs) throws XmlPullParserException, IOException {
         StringBuilder sb = new StringBuilder();
         sb.append(// @formatter:off
                         "<iq from='romeo@montague.example/dr4hcr0st3lup4c'" +
@@ -98,9 +138,9 @@ public class JingleProviderTest {
                              " to='juliet@capulet.example/yn0cl4bnw0yr3vym'" +
                              " type='set'>" +
                           "<jingle xmlns='urn:xmpp:jingle:1' " +
-                                " action='session-initiate' " +
-                             " initiator='romeo@montague.example/dr4hcr0st3lup4c' " +
-                                   " sid='851ba2'>" +
+                                "action='session-initiate' " +
+                                "initiator='romeo@montague.example/dr4hcr0st3lup4c' " +
+                                "sid='851ba2'>" +
                         "<content creator='initiator' name='a-file-offer' senders='initiator'>"
                    // @formatter:on
                   );
@@ -114,9 +154,6 @@ public class JingleProviderTest {
                   // @formatter:on
                  );
 
-        String jingleStanza = sb.toString();
-
-        XmlPullParser parser = PacketParserUtils.getParserFor(jingleStanza);
-        return parser;
+        return sb;
     }
 }

smack-extensions/src/test/java/org/jivesoftware/smackx/pubsub/provider/ItemProviderTest.java

@@ -0,0 +1,48 @@
+/**
+ *
+ * Copyright 2021 Florian Schmaus
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smackx.pubsub.provider;
+
+import java.io.IOException;
+
+import org.jivesoftware.smack.parsing.SmackParsingException;
+import org.jivesoftware.smack.test.util.SmackTestUtil;
+import org.jivesoftware.smack.xml.XmlPullParserException;
+
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.EnumSource;
+
+public class ItemProviderTest {
+
+    /**
+     * Check that {@link ItemProvider} is able to parse items which have whitespace before their Payload.
+     *
+     * @param parserKind the used parser Kind
+     * @throws XmlPullParserException if an XML pull parser exception occurs.
+     * @throws IOException if an IO exception occurs.
+     * @throws SmackParsingException if an Smack parsing exception occurs.
+     * @see <a href="https://igniterealtime.atlassian.net/jira/software/c/projects/SMACK/issues/SMACK-918">SMACK-918</a>
+     */
+    @ParameterizedTest
+    @EnumSource(SmackTestUtil.XmlPullParserKind.class)
+    public void whitespaceBeforeItemPayload(SmackTestUtil.XmlPullParserKind parserKind) throws XmlPullParserException, IOException, SmackParsingException {
+        String item = "<item id='13a3710c-68c3-4da2-8484-d8d9c77af91e' xmlns='http://jabber.org/protocol/pubsub#event'>"
+                    + "\n <geoloc xmlns='http://jabber.org/protocol/geoloc' xml:lang='en'/>"
+                    + "</item>";
+        SmackTestUtil.parse(item, ItemProvider.class, parserKind);
+    }
+
+}

smack-extensions/src/test/java/org/jivesoftware/smackx/xdata/FormFieldTest.java

@@ -17,6 +17,8 @@
 package org.jivesoftware.smackx.xdata;
 
 import static org.jivesoftware.smack.test.util.XmlAssertUtil.assertXmlSimilar;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import org.junit.jupiter.api.Test;
 import org.jxmpp.jid.JidTestUtil;
@@ -35,4 +37,18 @@ class FormFieldTest {
         assertXmlSimilar(expectedXml, xml);
     }
 
+    @Test
+    public void testEmptyLabel() {
+        TextSingleFormField.Builder builder = FormField.textSingleBuilder("type");
+        builder.setLabel("");
+        TextSingleFormField formField = builder.build();
+
+        assertEquals("", formField.getLabel());
+    }
+
+    @Test
+    public void testThrowExceptionWhenNullLabel() {
+        TextSingleFormField.Builder builder = FormField.textSingleBuilder("type");
+        assertThrows(IllegalArgumentException.class, () -> builder.setLabel(null));
+    }
 }

smack-extensions/src/test/java/org/jivesoftware/smackx/xdata/provider/DataFormProviderTest.java

@@ -115,4 +115,33 @@ public class DataFormProviderTest {
         assertEquals(2, items.size());
     }
 
+    @Test
+    public void testRetrieveFieldWithEmptyLabel() throws XmlPullParserException, IOException, SmackParsingException {
+
+        String form =
+                "<x xmlns='jabber:x:data' type='form'>" +
+                        "  <title>Advanced User Search</title>" +
+                        "  <instructions>The following fields are available for searching. Wildcard (*) characters are allowed as part of the query.</instructions>" +
+                        "  <field var='FORM_TYPE' label='' type='hidden'>" +
+                        "    <value>jabber:iq:search</value>" +
+                        "  </field>" +
+                        "  <field label='Search' var='search'>" +
+                        "    <required/>" +
+                        "  </field>" +
+                        "  <field label='Username' var='Username' type='boolean'>" +
+                        "    <value>true</value>" +
+                        "  </field>" +
+                        "  <field label='Name' var='Name' type='boolean'>" +
+                        "    <value>true</value>" +
+                        "  </field>" +
+                        "  <field label='Email' var='Email' type='boolean'>" +
+                        "    <value>true</value>" +
+                        "  </field>" +
+                        "</x>";
+        XmlPullParser parser = PacketParserUtils.getParserFor(form);
+        DataForm dataForm = DataFormProvider.INSTANCE.parse(parser);
+        FormField usernameFormField = dataForm.getField("FORM_TYPE");
+        assertEquals(FormField.Type.hidden, usernameFormField.getType());
+        assertEquals("", usernameFormField.getLabel());
+    }
 }

smack-extensions/src/test/java/org/jivesoftware/smackx/xhtmlim/provider/XHTMLExtensionProviderTest.java

@@ -39,7 +39,6 @@ public class XHTMLExtensionProviderTest {
     public void parsesWell() throws IOException, XmlPullParserException {
         InputStream inputStream = getClass().getResourceAsStream(XHTML_EXTENSION_SAMPLE_RESOURCE_NAME);
         XmlPullParser parser = PacketParserUtils.getParserFor(inputStream);
-        parser.next();
 
         XHTMLExtensionProvider provider = new XHTMLExtensionProvider();
         ExtensionElement extension = provider.parse(parser, parser.getDepth(), null);

smack-im/src/main/java/org/jivesoftware/smack/roster/Roster.java

@@ -469,11 +469,14 @@ public final class Roster extends Manager {
             @Override
             public void processException(Exception exception) {
                 rosterState = RosterState.uninitialized;
-                Level logLevel;
+                Level logLevel = Level.SEVERE;
                 if (exception instanceof NotConnectedException) {
                     logLevel = Level.FINE;
-                } else {
-                    logLevel = Level.SEVERE;
+                } else if (exception instanceof XMPPErrorException) {
+                    Condition condition = ((XMPPErrorException) exception).getStanzaError().getCondition();
+                    if (condition == Condition.feature_not_implemented || condition == Condition.service_unavailable) {
+                        logLevel = Level.FINE;
+                    }
                 }
                 LOGGER.log(logLevel, "Exception reloading roster", exception);
                 for (RosterLoadedListener listener : rosterLoadedListeners) {

smack-integration-test/src/main/java/org/igniterealtime/smack/inttest/AbstractSmackIntegrationTest.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2015-2020 Florian Schmaus
+ * Copyright 2015-2021 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -85,6 +85,7 @@ public abstract class AbstractSmackIntegrationTest extends AbstractSmackIntTest
      * @param action the action to perform.
      * @throws Exception in case of an exception.
      */
+    @SuppressWarnings("ThreadPriorityCheck")
     protected void performActionAndWaitForPresence(XMPPConnection conA, XMPPConnection conB, ThrowingRunnable action)
                     throws Exception {
         final SimpleResultSyncPoint presenceReceivedSyncPoint = new SimpleResultSyncPoint();
@@ -109,5 +110,8 @@ public abstract class AbstractSmackIntegrationTest extends AbstractSmackIntTest
         } finally {
             conA.removeAsyncStanzaListener(presenceListener);
         }
+
+        // TODO: Ugly hack to make tests using this method more reliable. Ideally no test would use this method.
+        Thread.yield();
     }
 }

smack-integration-test/src/main/java/org/igniterealtime/smack/inttest/Configuration.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2015-2020 Florian Schmaus
+ * Copyright 2015-2021 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,8 +19,11 @@ package org.igniterealtime.smack.inttest;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
+import java.lang.reflect.Method;
 import java.security.KeyManagementException;
 import java.security.NoSuchAlgorithmException;
+import java.util.Collections;
+import java.util.HashMap;
 import java.util.HashSet;
 import java.util.LinkedList;
 import java.util.List;
@@ -33,6 +36,7 @@ import javax.net.ssl.SSLContext;
 
 import org.jivesoftware.smack.ConnectionConfiguration.SecurityMode;
 import org.jivesoftware.smack.debugger.ConsoleDebugger;
+import org.jivesoftware.smack.util.CollectionUtil;
 import org.jivesoftware.smack.util.Function;
 import org.jivesoftware.smack.util.Objects;
 import org.jivesoftware.smack.util.ParserUtils;
@@ -101,8 +105,12 @@ public final class Configuration {
 
     public final Set<String> enabledTests;
 
+    private final Map<String, Set<String>> enabledTestsMap;
+
     public final Set<String> disabledTests;
 
+    private final Map<String, Set<String>> disabledTestsMap;
+
     public final String defaultConnectionNickname;
 
     public final Set<String> enabledConnections;
@@ -117,6 +125,13 @@ public final class Configuration {
 
     public final DnsResolver dnsResolver;
 
+    public enum CompatibilityMode {
+        standardsCompliant,
+        ejabberd,
+    }
+
+    public final CompatibilityMode compatibilityMode;
+
     private Configuration(Configuration.Builder builder) throws KeyManagementException, NoSuchAlgorithmException {
         service = Objects.requireNonNull(builder.service,
                         "'service' must be set. Either via 'properties' files or via system property 'sinttest.service'.");
@@ -162,8 +177,10 @@ public final class Configuration {
         this.accountTwoPassword = builder.accountTwoPassword;
         this.accountThreeUsername = builder.accountThreeUsername;
         this.accountThreePassword = builder.accountThreePassword;
-        this.enabledTests = builder.enabledTests;
-        this.disabledTests = builder.disabledTests;
+        this.enabledTests = CollectionUtil.nullSafeUnmodifiableSet(builder.enabledTests);
+        this.enabledTestsMap = convertTestsToMap(enabledTests);
+        this.disabledTests =  CollectionUtil.nullSafeUnmodifiableSet(builder.disabledTests);
+        this.disabledTestsMap = convertTestsToMap(disabledTests);
         this.defaultConnectionNickname = builder.defaultConnectionNickname;
         this.enabledConnections = builder.enabledConnections;
         this.disabledConnections = builder.disabledConnections;
@@ -192,6 +209,7 @@ public final class Configuration {
         this.verbose = builder.verbose;
 
         this.dnsResolver = builder.dnsResolver;
+        this.compatibilityMode = builder.compatibilityMode;
     }
 
     public boolean isAccountRegistrationPossible() {
@@ -246,6 +264,8 @@ public final class Configuration {
 
         private DnsResolver dnsResolver = DnsResolver.minidns;
 
+        private CompatibilityMode compatibilityMode = CompatibilityMode.standardsCompliant;
+
         private Builder() {
         }
 
@@ -427,6 +447,20 @@ public final class Configuration {
             return setDnsResolver(dnsResolver);
         }
 
+        public Builder setCompatibilityMode(CompatibilityMode compatibilityMode) {
+            this.compatibilityMode = compatibilityMode;
+            return this;
+        }
+
+        public Builder setCompatibilityMode(String compatibilityModeString) {
+            if (compatibilityModeString == null) {
+                return this;
+            }
+
+            CompatibilityMode compatibilityMode = CompatibilityMode.valueOf(compatibilityModeString);
+            return setCompatibilityMode(compatibilityMode);
+        }
+
         public Configuration build() throws KeyManagementException, NoSuchAlgorithmException {
             return new Configuration(this);
         }
@@ -500,6 +534,8 @@ public final class Configuration {
 
         builder.setDnsResolver(properties.getProperty("dnsResolver"));
 
+        builder.setCompatibilityMode(properties.getProperty("compatibilityMode"));
+
         return builder.build();
     }
 
@@ -551,4 +587,112 @@ public final class Configuration {
         });
     }
 
+    private static Map<String, Set<String>> convertTestsToMap(Set<String> tests) {
+        Map<String, Set<String>> res = new HashMap<>();
+        for (String test : tests) {
+            String[] testParts = test.split("\\.");
+            if (testParts.length == 1) {
+                // The whole test specification does not contain a dot, assume it is a test class specification.
+                res.put(test, Collections.emptySet());
+                continue;
+            }
+
+            String lastTestPart = testParts[testParts.length - 1];
+            if (lastTestPart.isEmpty()) {
+                throw new IllegalArgumentException("Invalid test specifier: " + test);
+            }
+
+            char firstCharOfLastTestPart = lastTestPart.charAt(0);
+            if (!Character.isLowerCase(firstCharOfLastTestPart)) {
+                // The first character of the last test part is not lowercase, assume this is a fully qualified test
+                // class specification, e.g. org.foo.bar.TestClass.
+                res.put(test, Collections.emptySet());
+            }
+
+            // The first character of the last test part is lowercase, assume this is a test class *and* method name
+            // specification.
+            String testMethodName = lastTestPart;
+            int classPartsCount = testParts.length - 1;
+            String[] classParts = new String[classPartsCount];
+            System.arraycopy(testParts, 0, classParts, 0, classPartsCount);
+            String testClass = String.join(".", classParts);
+
+            res.compute(testClass, (k, v) -> {
+                if (v == null) {
+                    v = new HashSet<>();
+                }
+                v.add(testMethodName);
+                return v;
+            });
+        }
+        return res;
+    }
+
+    private static Set<String> getKey(Class<?> testClass, Map<String, Set<String>> testsMap) {
+        String className = testClass.getName();
+        if (testsMap.containsKey(className)) {
+            return testsMap.get(className);
+        }
+
+        String unqualifiedClassName = testClass.getSimpleName();
+        if (testsMap.containsKey(unqualifiedClassName)) {
+            return testsMap.get(unqualifiedClassName);
+        }
+
+        return null;
+    }
+
+    private static boolean contains(Class<? extends AbstractSmackIntTest> testClass, Map<String, Set<String>> testsMap) {
+        Set<String> enabledMethods = getKey(testClass, testsMap);
+        return enabledMethods != null;
+   }
+
+    public boolean isClassEnabled(Class<? extends AbstractSmackIntTest> testClass) {
+        if (enabledTestsMap.isEmpty()) {
+            return true;
+        }
+
+        return contains(testClass, enabledTestsMap);
+    }
+
+    public boolean isClassDisabled(Class<? extends AbstractSmackIntTest> testClass) {
+        if (disabledTestsMap.isEmpty()) {
+            return false;
+        }
+
+        return contains(testClass, disabledTestsMap);
+    }
+
+    private static boolean contains(Method method, Map<String, Set<String>> testsMap) {
+        Class<?> testClass = method.getDeclaringClass();
+        Set<String> methods = getKey(testClass, testsMap);
+
+        if (methods == null) {
+            return false;
+        }
+
+        if (methods.isEmpty()) {
+            return true;
+        }
+
+        String methodName = method.getName();
+        return methods.contains(methodName);
+    }
+
+    public boolean isMethodEnabled(Method method) {
+        if (enabledTestsMap.isEmpty()) {
+            return true;
+        }
+
+        return contains(method, enabledTestsMap);
+    }
+
+    public boolean isMethodDisabled(Method method) {
+        if (disabledTestsMap.isEmpty()) {
+            return false;
+        }
+
+        return contains(method, disabledTestsMap);
+    }
+
 }

smack-integration-test/src/main/java/org/igniterealtime/smack/inttest/SmackIntegrationTestFramework.java

@@ -282,13 +282,13 @@ public class SmackIntegrationTestFramework {
                 continue;
             }
 
-            if (config.enabledTests != null && !isInSet(testClass, config.enabledTests)) {
+            if (!config.isClassEnabled(testClass)) {
                 DisabledTestClass disabledTestClass = new DisabledTestClass(testClass, "Skipping test class " + testClassName + " because it is not enabled");
                 testRunResult.disabledTestClasses.add(disabledTestClass);
                 continue;
             }
 
-            if (isInSet(testClass, config.disabledTests)) {
+            if (config.isClassDisabled(testClass)) {
                 DisabledTestClass disabledTestClass = new DisabledTestClass(testClass, "Skipping test class " + testClassName + " because it is disalbed");
                 testRunResult.disabledTestClasses.add(disabledTestClass);
                 continue;
@@ -377,14 +377,13 @@ public class SmackIntegrationTestFramework {
             while (it.hasNext()) {
                 final Method method = it.next();
                 final String methodName = method.getName();
-                if (config.enabledTests != null && !(config.enabledTests.contains(methodName)
-                                || isInSet(testClass, config.enabledTests))) {
+                if (!config.isMethodEnabled(method)) {
                     DisabledTest disabledTest = new DisabledTest(method, "Skipping test method " + methodName + " because it is not enabled");
                     testRunResult.disabledTests.add(disabledTest);
                     it.remove();
                     continue;
                 }
-                if (config.disabledTests != null && config.disabledTests.contains(methodName)) {
+                if (config.isMethodDisabled(method)) {
                     DisabledTest disabledTest = new DisabledTest(method, "Skipping test method " + methodName + " because it is disabled");
                     testRunResult.disabledTests.add(disabledTest);
                     it.remove();
@@ -607,15 +606,6 @@ public class SmackIntegrationTestFramework {
         return (Exception) e;
     }
 
-    private static boolean isInSet(Class<?> clz, Set<String> classes) {
-        if (classes == null) {
-            return false;
-        }
-        final String className = clz.getName();
-        final String unqualifiedClassName = clz.getSimpleName();
-        return classes.contains(className) || classes.contains(unqualifiedClassName);
-    }
-
     public static final class TestRunResult {
 
         /**

smack-integration-test/src/main/java/org/igniterealtime/smack/inttest/util/IntegrationTestRosterUtil.java

@@ -24,6 +24,7 @@ import org.jivesoftware.smack.SmackException.NotLoggedInException;
 import org.jivesoftware.smack.XMPPConnection;
 import org.jivesoftware.smack.XMPPException.XMPPErrorException;
 import org.jivesoftware.smack.packet.Presence;
+import org.jivesoftware.smack.packet.StanzaError;
 import org.jivesoftware.smack.roster.AbstractPresenceEventListener;
 import org.jivesoftware.smack.roster.PresenceEventListener;
 import org.jivesoftware.smack.roster.Roster;
@@ -99,7 +100,16 @@ public class IntegrationTestRosterUtil {
         if (c2Entry == null) {
             return;
         }
+        try {
             roster.removeEntry(c2Entry);
+        } catch (XMPPErrorException e) {
+            // Account for race conditions: server-sided, the item might already have been removed.
+            if (e.getStanzaError().getCondition() == StanzaError.Condition.item_not_found) {
+                // Trying to remove non-existing item. As it needs to be gone, this is fine.
+                return;
+            }
+            throw e;
+        }
     }
 
 }

smack-integration-test/src/main/java/org/jivesoftware/smackx/geolocation/GeolocationIntegrationTest.java

@@ -23,8 +23,9 @@ import org.jivesoftware.smack.SmackException.NoResponseException;
 import org.jivesoftware.smack.SmackException.NotConnectedException;
 import org.jivesoftware.smack.SmackException.NotLoggedInException;
 import org.jivesoftware.smack.XMPPException.XMPPErrorException;
-import org.jivesoftware.smack.packet.Message;
 
+import org.jivesoftware.smackx.disco.EntityCapabilitiesChangedListener;
+import org.jivesoftware.smackx.disco.ServiceDiscoveryManager;
 import org.jivesoftware.smackx.geoloc.GeoLocationManager;
 import org.jivesoftware.smackx.geoloc.packet.GeoLocation;
 import org.jivesoftware.smackx.pep.PepEventListener;
@@ -35,7 +36,7 @@ import org.igniterealtime.smack.inttest.annotations.AfterClass;
 import org.igniterealtime.smack.inttest.annotations.SmackIntegrationTest;
 import org.igniterealtime.smack.inttest.util.IntegrationTestRosterUtil;
 import org.igniterealtime.smack.inttest.util.SimpleResultSyncPoint;
-import org.jxmpp.jid.EntityBareJid;
+import org.junit.jupiter.api.Assertions;
 import org.jxmpp.util.XmppDateTime;
 
 public class GeolocationIntegrationTest extends AbstractSmackIntegrationTest {
@@ -49,10 +50,21 @@ public class GeolocationIntegrationTest extends AbstractSmackIntegrationTest {
         glm2 = GeoLocationManager.getInstanceFor(conTwo);
     }
 
+    @AfterClass
+    public void unsubscribe() throws NotLoggedInException, NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
+        IntegrationTestRosterUtil.ensureBothAccountsAreNotInEachOthersRoster(conOne, conTwo);
+    }
+
+    /**
+     * Verifies that a notification is sent when a publication is received, assuming that notification filtering
+     * has been adjusted to allow for the notification to be delivered.
+     *
+     * @throws Exception if the test fails
+     */
     @SmackIntegrationTest
-    public void test() throws TimeoutException, Exception {
+    public void testNotification() throws Exception {
         GeoLocation.Builder builder = GeoLocation.builder();
-        GeoLocation geoLocation1 = builder.setAccuracy(23d)
+        GeoLocation data = builder.setAccuracy(23d)
                                             .setAlt(1000d)
                                             .setAltAccuracy(10d)
                                             .setArea("Delhi")
@@ -77,31 +89,163 @@ public class GeolocationIntegrationTest extends AbstractSmackIntegrationTest {
                                             .build();
 
         IntegrationTestRosterUtil.ensureBothAccountsAreSubscribedToEachOther(conOne, conTwo, timeout);
-        final SimpleResultSyncPoint geoLocationReceived = new SimpleResultSyncPoint();
-        final PepEventListener<GeoLocation> geoLocationListener = new PepEventListener<GeoLocation>() {
 
-            @Override
-            public void onPepEvent(EntityBareJid jid, GeoLocation geoLocation, String id, Message message) {
-                if (geoLocation.equals(geoLocation1)) {
+        final SimpleResultSyncPoint geoLocationReceived = new SimpleResultSyncPoint();
+
+        final PepEventListener<GeoLocation> geoLocationListener = (jid, geoLocation, id, message) -> {
+            if (geoLocation.equals(data)) {
                 geoLocationReceived.signal();
-                } else {
-                    geoLocationReceived.signalFailure("Received non matching GeoLocation");
-                }
             }
         };
 
-        glm2.addGeoLocationListener(geoLocationListener);
-
         try {
-            glm1.publishGeoLocation(geoLocation1);
-            geoLocationReceived.waitForResult(timeout);
+            // Register ConTwo's interest in receiving geolocation notifications, and wait for that interest to have been propagated.
+            registerListenerAndWait(glm2, ServiceDiscoveryManager.getInstanceFor(conTwo), geoLocationListener);
+
+            // Publish the data.
+            glm1.publishGeoLocation(data); // for the purpose of this test, this needs not be blocking/use publishAndWait();
+
+            // Wait for the data to be received.
+            try {
+                Object result = geoLocationReceived.waitForResult(timeout);
+
+                // Explicitly assert the success case.
+                Assertions.assertNotNull(result, "Expected to receive a PEP notification, but did not.");
+            } catch (TimeoutException e) {
+                Assertions.fail("Expected to receive a PEP notification, but did not.");
+            }
         } finally {
-            glm2.removeGeoLocationListener(geoLocationListener);
+            unregisterListener(glm2, geoLocationListener);
         }
     }
 
-    @AfterClass
-    public void unsubscribe() throws NotLoggedInException, NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
-        IntegrationTestRosterUtil.ensureBothAccountsAreNotInEachOthersRoster(conOne, conTwo);
+    /**
+     * Verifies that a notification for a previously sent publication is received as soon as notification filtering
+     * has been adjusted to allow for the notification to be delivered.
+     *
+     * @throws Exception if the test fails
+     */
+    @SmackIntegrationTest
+    public void testNotificationAfterFilterChange() throws Exception {
+        GeoLocation.Builder builder = GeoLocation.builder();
+        GeoLocation data = builder.setAccuracy(12d)
+                .setAlt(999d)
+                .setAltAccuracy(9d)
+                .setArea("Amsterdam")
+                .setBearing(9d)
+                .setBuilding("Test Building")
+                .setCountry("Netherlands")
+                .setCountryCode("NL")
+                .setDescription("My Description")
+                .setFloor("middle")
+                .setLat(25.098345d)
+                .setLocality("brilliant")
+                .setLon(77.992034)
+                .setPostalcode("110085")
+                .setRegion("North")
+                .setRoom("small")
+                .setSpeed(250.0d)
+                .setStreet("Wall Street")
+                .setText("Unit Testing GeoLocation 2")
+                .setTimestamp(XmppDateTime.parseDate("2007-02-19"))
+                .setTzo("+5:30")
+                .setUri(new URI("http://xmpp.org"))
+                .build();
+
+        IntegrationTestRosterUtil.ensureBothAccountsAreSubscribedToEachOther(conOne, conTwo, timeout);
+
+        final SimpleResultSyncPoint geoLocationReceived = new SimpleResultSyncPoint();
+
+        final PepEventListener<GeoLocation> geoLocationListener = (jid, geoLocation, id, message) -> {
+            if (geoLocation.equals(data)) {
+                geoLocationReceived.signal();
+            }
+        };
+
+        // TODO Ensure that pre-existing filtering notification excludes geolocation.
+        try {
+            // Publish the data
+            publishAndWait(glm1, ServiceDiscoveryManager.getInstanceFor(conOne), data);
+
+            // Adds listener, which implicitly publishes a disco/info filter for geolocation notification.
+            registerListenerAndWait(glm2, ServiceDiscoveryManager.getInstanceFor(conTwo), geoLocationListener);
+
+            // Wait for the data to be received.
+            try {
+                Object result = geoLocationReceived.waitForResult(timeout);
+
+                // Explicitly assert the success case.
+                Assertions.assertNotNull(result, "Expected to receive a PEP notification, but did not.");
+            } catch (TimeoutException e) {
+                Assertions.fail("Expected to receive a PEP notification, but did not.");
+            }
+        } finally {
+            unregisterListener(glm2, geoLocationListener);
+        }
+    }
+
+    /**
+     * Registers a listener for GeoLocation data. This implicitly publishes a CAPS update to include a notification
+     * filter for the geolocation node. This method blocks until the server has indicated that this update has been
+     * received.
+     *
+     * @param geoManager The GeoLocationManager instance for the connection that is expected to receive data.
+     * @param discoManager The ServiceDiscoveryManager instance for the connection that is expected to publish data.
+     * @param listener A listener instance for GeoLocation data that is to be registered.
+     *
+     * @throws Exception if the test fails
+     */
+    public void registerListenerAndWait(GeoLocationManager geoManager, ServiceDiscoveryManager discoManager, PepEventListener<GeoLocation> listener) throws Exception {
+        final SimpleResultSyncPoint notificationFilterReceived = new SimpleResultSyncPoint();
+        final EntityCapabilitiesChangedListener notificationFilterReceivedListener = info -> {
+            if (info.containsFeature(GeoLocationManager.GEOLOCATION_NODE + "+notify")) {
+                notificationFilterReceived.signal();
+            }
+        };
+
+        discoManager.addEntityCapabilitiesChangedListener(notificationFilterReceivedListener);
+        try {
+            geoManager.addGeoLocationListener(listener);
+            notificationFilterReceived.waitForResult(timeout);
+        } finally {
+            discoManager.removeEntityCapabilitiesChangedListener(notificationFilterReceivedListener);
+        }
+    }
+
+    /**
+     * The functionally reverse of {@link #registerListenerAndWait(GeoLocationManager, ServiceDiscoveryManager, PepEventListener)}
+     * with the difference of not being a blocking operation.
+     *
+     * @param geoManager The GeoLocationManager instance for the connection that was expected to receive data.
+     * @param listener A listener instance for GeoLocation data that is to be removed.
+     */
+    public void unregisterListener(GeoLocationManager geoManager, PepEventListener<GeoLocation> listener) {
+        // Does it make sense to have a method implementation that's one line? This is provided to allow for symmetry in the API.
+        geoManager.removeGeoLocationListener(listener);
+    }
+
+    /**
+     * Publish data using PEP, and block until the server has echoed the publication back to the publishing user.
+     *
+     * @param geoManager The GeoLocationManager instance for the connection that is expected to publish data.
+     * @param discoManager The ServiceDiscoveryManager instance for the connection that is expected to publish data.
+     * @param data The data to be published.
+     *
+     * @throws Exception if the test fails
+     */
+    public void publishAndWait(GeoLocationManager geoManager, ServiceDiscoveryManager discoManager, GeoLocation data) throws Exception {
+        final SimpleResultSyncPoint publicationEchoReceived = new SimpleResultSyncPoint();
+        final PepEventListener<GeoLocation> publicationEchoListener = (jid, geoLocation, id, message) -> {
+            if (geoLocation.equals(data)) {
+                publicationEchoReceived.signal();
+            }
+        };
+        try {
+            registerListenerAndWait(geoManager, discoManager, publicationEchoListener);
+            geoManager.addGeoLocationListener(publicationEchoListener);
+            geoManager.publishGeoLocation(data);
+        } finally {
+            geoManager.removeGeoLocationListener(publicationEchoListener);
+        }
     }
 }

smack-integration-test/src/main/java/org/jivesoftware/smackx/mood/MoodIntegrationTest.java

@@ -16,9 +16,13 @@
  */
 package org.jivesoftware.smackx.mood;
 
+import java.util.concurrent.TimeoutException;
+
 import org.jivesoftware.smack.SmackException;
 import org.jivesoftware.smack.XMPPException;
 
+import org.jivesoftware.smackx.disco.EntityCapabilitiesChangedListener;
+import org.jivesoftware.smackx.disco.ServiceDiscoveryManager;
 import org.jivesoftware.smackx.mood.element.MoodElement;
 import org.jivesoftware.smackx.pep.PepEventListener;
 
@@ -28,6 +32,7 @@ import org.igniterealtime.smack.inttest.annotations.AfterClass;
 import org.igniterealtime.smack.inttest.annotations.SmackIntegrationTest;
 import org.igniterealtime.smack.inttest.util.IntegrationTestRosterUtil;
 import org.igniterealtime.smack.inttest.util.SimpleResultSyncPoint;
+import org.junit.jupiter.api.Assertions;
 
 public class MoodIntegrationTest extends AbstractSmackIntegrationTest {
 
@@ -40,32 +45,155 @@ public class MoodIntegrationTest extends AbstractSmackIntegrationTest {
         mm2 = MoodManager.getInstanceFor(conTwo);
     }
 
-    @SmackIntegrationTest
-    public void test() throws Exception {
-        IntegrationTestRosterUtil.ensureBothAccountsAreSubscribedToEachOther(conOne, conTwo, timeout);
-
-        final SimpleResultSyncPoint moodReceived = new SimpleResultSyncPoint();
-
-        final PepEventListener<MoodElement> moodListener = (jid, moodElement, id, message) -> {
-            if (moodElement.getMood() == Mood.satisfied) {
-                moodReceived.signal();
-            }
-        };
-        mm2.addMoodListener(moodListener);
-
-        try {
-            mm1.setMood(Mood.satisfied);
-
-            moodReceived.waitForResult(timeout);
-        } finally {
-            mm2.removeMoodListener(moodListener);
-        }
-    }
-
     @AfterClass
     public void unsubscribe()
             throws SmackException.NotLoggedInException, XMPPException.XMPPErrorException,
             SmackException.NotConnectedException, InterruptedException, SmackException.NoResponseException {
         IntegrationTestRosterUtil.ensureBothAccountsAreNotInEachOthersRoster(conOne, conTwo);
     }
+
+    /**
+     * Verifies that a notification is sent when a publication is received, assuming that notification filtering
+     * has been adjusted to allow for the notification to be delivered.
+     *
+     * @throws Exception if the test fails
+     */
+    @SmackIntegrationTest
+    public void testNotification() throws Exception {
+        Mood data = Mood.satisfied;
+
+        IntegrationTestRosterUtil.ensureBothAccountsAreSubscribedToEachOther(conOne, conTwo, timeout);
+
+        final SimpleResultSyncPoint moodReceived = new SimpleResultSyncPoint();
+
+        final PepEventListener<MoodElement> moodListener = (jid, moodElement, id, message) -> {
+            if (moodElement.getMood().equals(data)) {
+                moodReceived.signal();
+            }
+        };
+
+        try {
+            // Register ConTwo's interest in receiving mood notifications, and wait for that interest to have been propagated.
+            registerListenerAndWait(mm2, ServiceDiscoveryManager.getInstanceFor(conTwo), moodListener);
+
+            // Publish the data.
+            mm1.setMood(data); // for the purpose of this test, this needs not be blocking/use publishAndWait();
+
+            // Wait for the data to be received.
+            try {
+                moodReceived.waitForResult(timeout);
+            } catch (TimeoutException e) {
+                Assertions.fail("Expected to receive a PEP notification, but did not.");
+            }
+        } finally {
+            unregisterListener(mm2, moodListener);
+        }
+    }
+
+    /**
+     * Verifies that a notification for a previously sent publication is received as soon as notification filtering
+     * has been adjusted to allow for the notification to be delivered.
+     *
+     * @throws Exception if the test fails
+     */
+    @SmackIntegrationTest
+    public void testNotificationAfterFilterChange() throws Exception {
+        Mood data = Mood.cautious;
+
+        IntegrationTestRosterUtil.ensureBothAccountsAreSubscribedToEachOther(conOne, conTwo, timeout);
+
+        final SimpleResultSyncPoint moodReceived = new SimpleResultSyncPoint();
+
+        final PepEventListener<MoodElement> moodListener = (jid, moodElement, id, message) -> {
+            if (moodElement.getMood().equals(data)) {
+                moodReceived.signal();
+            }
+        };
+
+        // TODO Ensure that pre-existing filtering notification excludes mood.
+        try {
+            // Publish the data
+            publishAndWait(mm1, ServiceDiscoveryManager.getInstanceFor(conOne), data);
+
+            // Adds listener, which implicitly publishes a disco/info filter for mood notification.
+            registerListenerAndWait(mm2, ServiceDiscoveryManager.getInstanceFor(conTwo), moodListener);
+
+            // Wait for the data to be received.
+            try {
+                Object result = moodReceived.waitForResult(timeout);
+
+                // Explicitly assert the success case.
+                Assertions.assertNotNull(result, "Expected to receive a PEP notification, but did not.");
+            } catch (TimeoutException e) {
+                Assertions.fail("Expected to receive a PEP notification, but did not.");
+            }
+        } finally {
+            unregisterListener(mm2, moodListener);
+        }
+    }
+
+    /**
+     * Registers a listener for User Tune data. This implicitly publishes a CAPS update to include a notification
+     * filter for the mood node. This method blocks until the server has indicated that this update has been
+     * received.
+     *
+     * @param moodManager The MoodManager instance for the connection that is expected to receive data.
+     * @param discoManager The ServiceDiscoveryManager instance for the connection that is expected to publish data.
+     * @param listener A listener instance for Mood data that is to be registered.
+     *
+     * @throws Exception if the test fails
+     */
+    public void registerListenerAndWait(MoodManager moodManager, ServiceDiscoveryManager discoManager, PepEventListener<MoodElement> listener) throws Exception {
+        final SimpleResultSyncPoint notificationFilterReceived = new SimpleResultSyncPoint();
+        final EntityCapabilitiesChangedListener notificationFilterReceivedListener = info -> {
+            if (info.containsFeature(MoodManager.MOOD_NODE + "+notify")) {
+                notificationFilterReceived.signal();
+            }
+        };
+
+        discoManager.addEntityCapabilitiesChangedListener(notificationFilterReceivedListener);
+        try {
+            moodManager.addMoodListener(listener);
+            notificationFilterReceived.waitForResult(timeout);
+        } finally {
+            discoManager.removeEntityCapabilitiesChangedListener(notificationFilterReceivedListener);
+        }
+    }
+
+    /**
+     * The functionally reverse of {@link #registerListenerAndWait(MoodManager, ServiceDiscoveryManager, PepEventListener)}
+     * with the difference of not being a blocking operation.
+     *
+     * @param moodManager The MoodManager instance for the connection that was expected to receive data.
+     * @param listener A listener instance for Mood data that is to be removed.
+     */
+    public void unregisterListener(MoodManager moodManager, PepEventListener<MoodElement> listener) {
+        // Does it make sense to have a method implementation that's one line? This is provided to allow for symmetry in the API.
+        moodManager.removeMoodListener(listener);
+    }
+
+    /**
+     * Publish data using PEP, and block until the server has echoed the publication back to the publishing user.
+     *
+     * @param moodManager The MoodManager instance for the connection that is expected to publish data.
+     * @param discoManager The ServiceDiscoveryManager instance for the connection that is expected to publish data.
+     * @param data The data to be published.
+     *
+     * @throws Exception if the test fails
+     */
+    public void publishAndWait(MoodManager moodManager, ServiceDiscoveryManager discoManager, Mood data) throws Exception {
+        final SimpleResultSyncPoint publicationEchoReceived = new SimpleResultSyncPoint();
+        final PepEventListener<MoodElement> publicationEchoListener = (jid, moodElement, id, message) -> {
+            if (moodElement.getMood().equals(data)) {
+                publicationEchoReceived.signal();
+            }
+        };
+        try {
+            registerListenerAndWait(moodManager, discoManager, publicationEchoListener);
+            moodManager.addMoodListener(publicationEchoListener);
+            moodManager.setMood(data);
+        } finally {
+            moodManager.removeMoodListener(publicationEchoListener);
+        }
+    }
 }

smack-integration-test/src/main/java/org/jivesoftware/smackx/muc/AbstractMultiUserChatIntegrationTest.java

@@ -22,8 +22,6 @@ import java.util.List;
 import org.jivesoftware.smack.SmackException;
 import org.jivesoftware.smack.XMPPException;
 import org.jivesoftware.smack.util.StringUtils;
-import org.jivesoftware.smackx.xdata.form.FillableForm;
-import org.jivesoftware.smackx.xdata.form.Form;
 
 import org.igniterealtime.smack.inttest.AbstractSmackIntegrationTest;
 import org.igniterealtime.smack.inttest.SmackIntegrationTestEnvironment;
@@ -57,10 +55,9 @@ public class AbstractMultiUserChatIntegrationTest extends AbstractSmackIntegrati
         if (services.isEmpty()) {
             throw new TestNotPossibleException("No MUC (XEP-45) service found");
         }
-        else {
+
         mucService = services.get(0);
     }
-    }
 
     /**
      * Gets a random room name.
@@ -90,18 +87,57 @@ public class AbstractMultiUserChatIntegrationTest extends AbstractSmackIntegrati
         muc.destroy("test fixture teardown", null);
     }
 
-    static void createMuc(MultiUserChat muc, String resourceName) throws SmackException.NoResponseException, XMPPException.XMPPErrorException, InterruptedException, MultiUserChatException.MucAlreadyJoinedException, SmackException.NotConnectedException, MultiUserChatException.MissingMucCreationAcknowledgeException, MultiUserChatException.NotAMucServiceException, XmppStringprepException {
-        MultiUserChat.MucCreateConfigFormHandle handle = muc.create(Resourcepart.from(resourceName));
-        if (handle != null) {
-            handle.makeInstant();
-        }
+    static void createMuc(MultiUserChat muc, Resourcepart resourceName) throws
+            SmackException.NoResponseException, XMPPException.XMPPErrorException,
+            InterruptedException, MultiUserChatException.MucAlreadyJoinedException,
+            SmackException.NotConnectedException,
+            MultiUserChatException.MissingMucCreationAcknowledgeException,
+            MultiUserChatException.NotAMucServiceException {
+        muc.create(resourceName).makeInstant();
     }
 
-    static void createModeratedMuc(MultiUserChat muc, String resourceName) throws SmackException.NoResponseException, XMPPException.XMPPErrorException, InterruptedException, MultiUserChatException.MucAlreadyJoinedException, SmackException.NotConnectedException, MultiUserChatException.MissingMucCreationAcknowledgeException, MultiUserChatException.NotAMucServiceException, XmppStringprepException {
-        muc.create(Resourcepart.from(resourceName));
-        Form configForm = muc.getConfigurationForm();
-        FillableForm answerForm = configForm.getFillableForm();
-        answerForm.setAnswer("muc#roomconfig_moderatedroom", true); //TODO Add this to the MucConfigFormManager?
-        muc.sendConfigurationForm(answerForm);
+    static void createMuc(MultiUserChat muc, String nickname) throws
+            XmppStringprepException, MultiUserChatException.MucAlreadyJoinedException,
+            XMPPException.XMPPErrorException, SmackException.NotConnectedException,
+            MultiUserChatException.MissingMucCreationAcknowledgeException,
+            SmackException.NoResponseException, InterruptedException,
+            MultiUserChatException.NotAMucServiceException {
+        createMuc(muc, Resourcepart.from(nickname));
+    }
+
+    static void createMembersOnlyMuc(MultiUserChat muc, Resourcepart resourceName) throws
+            SmackException.NoResponseException, XMPPException.XMPPErrorException,
+            InterruptedException, MultiUserChatException.MucAlreadyJoinedException,
+            SmackException.NotConnectedException,
+            MultiUserChatException.MissingMucCreationAcknowledgeException,
+            MultiUserChatException.MucConfigurationNotSupportedException,
+            MultiUserChatException.NotAMucServiceException {
+        muc.create(resourceName)
+            .getConfigFormManager()
+            .makeMembersOnly()
+            .submitConfigurationForm();
+    }
+
+    static void createModeratedMuc(MultiUserChat muc, Resourcepart resourceName)
+                    throws SmackException.NoResponseException, XMPPException.XMPPErrorException, InterruptedException,
+                    MultiUserChatException.MucAlreadyJoinedException, SmackException.NotConnectedException,
+                    MultiUserChatException.MissingMucCreationAcknowledgeException,
+                    MultiUserChatException.NotAMucServiceException,
+                    MultiUserChatException.MucConfigurationNotSupportedException {
+        muc.create(resourceName)
+            .getConfigFormManager()
+            .makeModerated()
+            .submitConfigurationForm();
+    }
+
+    static void createHiddenMuc(MultiUserChat muc, Resourcepart resourceName)
+                    throws SmackException.NoResponseException, XMPPException.XMPPErrorException, InterruptedException,
+                    MultiUserChatException.MucAlreadyJoinedException, SmackException.NotConnectedException,
+                    MultiUserChatException.MissingMucCreationAcknowledgeException, MultiUserChatException.NotAMucServiceException, XmppStringprepException,
+                    MultiUserChatException.MucConfigurationNotSupportedException {
+        muc.create(resourceName)
+            .getConfigFormManager()
+            .makeHidden()
+            .submitConfigurationForm();
     }
 }