Rework WebSocket code

Related to SMACK-835.

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

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2009 Jive Software, 2018-2020 Florian Schmaus.
+ * Copyright 2009 Jive Software, 2018-2021 Florian Schmaus.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -2201,18 +2201,29 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
         return SMACK_REACTOR.schedule(runnable, delay, unit, ScheduledAction.Kind.NonBlocking);
     }
 
-    protected void onStreamOpen(XmlPullParser parser) {
+    /**
-        // We found an opening stream.
+     * Must be called when a XMPP stream open tag is encountered. Sets values like the stream ID and the incoming stream
-        if ("jabber:client".equals(parser.getNamespace(null))) {
+     * XML environment.
-            streamId = parser.getAttributeValue("", "id");
+     * <p>
+     * This method also returns a matching stream close tag. For example if the stream open is {@code <stream …>}, then
+     * {@code </stream>} is returned. But if it is {@code <stream:stream>}, then {@code </stream:stream>} is returned.
+     * Or if it is {@code <foo:stream>}, then {@code </foo:stream>} is returned.
+     * </p>
+     *
+     * @param parser an XML parser that is positioned at the start of the stream open.
+     * @return a String representing the corresponding stream end tag.
+     */
+    protected String onStreamOpen(XmlPullParser parser) {
+        assert StreamOpen.ETHERX_JABBER_STREAMS_NAMESPACE.equals(parser.getNamespace());
+        assert StreamOpen.UNPREFIXED_ELEMENT.equals(parser.getName());
+
+        streamId = parser.getAttributeValue("id");
         incomingStreamXmlEnvironment = XmlEnvironment.from(parser);
 
-            String reportedServerDomainString = parser.getAttributeValue("", "from");
+        String reportedServerDomainString = parser.getAttributeValue("from");
-            if (reportedServerDomainString == null) {
         // RFC 6120 § 4.7.1. makes no explicit statement whether or not 'from' in the stream open from the server
         // in c2s connections is required or not.
-                return;
+        if (reportedServerDomainString != null) {
-            }
             DomainBareJid reportedServerDomain;
             try {
                 reportedServerDomain = JidCreate.domainBareFrom(reportedServerDomainString);
@@ -2226,6 +2237,12 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
                         + "' as reported by server could not be transformed to a valid JID", e);
             }
         }
+
+        String prefix = parser.getPrefix();
+        if (StringUtils.isNotEmpty(prefix)) {
+            return "</" + prefix + ":stream>";
+        }
+        return "</stream>";
     }
 
     protected final void sendStreamOpen() throws NotConnectedException, InterruptedException {
@@ -2233,7 +2250,7 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
         // possible. The 'to' attribute is *always* available. The 'from' attribute if set by the user and no external
         // mechanism is used to determine the local entity (user). And the 'id' attribute is available after the first
         // response from the server (see e.g. RFC 6120 § 9.1.1 Step 2.)
-        CharSequence to = getXMPPServiceDomain();
+        DomainBareJid to = getXMPPServiceDomain();
         CharSequence from = null;
         CharSequence localpart = config.getUsername();
         if (localpart != null) {
@@ -2247,7 +2264,7 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
         updateOutgoingStreamXmlEnvironmentOnStreamOpen(streamOpen);
     }
 
-    protected AbstractStreamOpen getStreamOpen(CharSequence to, CharSequence from, String id, String lang) {
+    protected AbstractStreamOpen getStreamOpen(DomainBareJid to, CharSequence from, String id, String lang) {
         return new StreamOpen(to, from, id, lang);
     }
 

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

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2017-2020 Florian Schmaus
+ * Copyright 2017-2021 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -75,6 +75,10 @@ public abstract class SmackFuture<V, E extends Exception> implements Future<V>,
 
     @Override
     public final synchronized boolean isDone() {
+        return result != null || exception != null || cancelled;
+    }
+
+    public final synchronized boolean wasSuccessful() {
         return result != null;
     }
 
@@ -162,6 +166,10 @@ public abstract class SmackFuture<V, E extends Exception> implements Future<V>,
         return result;
     }
 
+    public E getExceptionIfAvailable() {
+        return exception;
+    }
+
     protected final synchronized void maybeInvokeCallbacks() {
         if (cancelled) {
             return;
@@ -326,6 +334,11 @@ public abstract class SmackFuture<V, E extends Exception> implements Future<V>,
         return future;
     }
 
+    public static boolean await(Collection<? extends SmackFuture<?, ?>> futures, long timeout)
+                    throws InterruptedException {
+        return await(futures, timeout, TimeUnit.MILLISECONDS);
+    }
+
     public static boolean await(Collection<? extends SmackFuture<?, ?>> futures, long timeout, TimeUnit unit) throws InterruptedException {
         CountDownLatch latch = new CountDownLatch(futures.size());
         for (SmackFuture<?, ?> future : futures) {

smack-core/src/main/java/org/jivesoftware/smack/c2s/ModularXmppClientToServerConnection.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2018-2020 Florian Schmaus
+ * Copyright 2018-2021 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -139,13 +139,8 @@ public final class ModularXmppClientToServerConnection extends AbstractXMPPConne
             }
 
             @Override
-            public void setCurrentConnectionExceptionAndNotify(Exception exception) {
+            public String onStreamOpen(XmlPullParser parser) {
-                ModularXmppClientToServerConnection.this.setCurrentConnectionExceptionAndNotify(exception);
+                return ModularXmppClientToServerConnection.this.onStreamOpen(parser);
-            }
-
-            @Override
-            public void onStreamOpen(XmlPullParser parser) {
-                ModularXmppClientToServerConnection.this.onStreamOpen(parser);
             }
 
             @Override
@@ -571,7 +566,7 @@ public final class ModularXmppClientToServerConnection extends AbstractXMPPConne
     }
 
     @Override
-    protected AbstractStreamOpen getStreamOpen(CharSequence to, CharSequence from, String id, String lang) {
+    protected AbstractStreamOpen getStreamOpen(DomainBareJid to, CharSequence from, String id, String lang) {
         StreamOpenAndCloseFactory streamOpenAndCloseFactory = activeTransport.getStreamOpenAndCloseFactory();
         return streamOpenAndCloseFactory.createStreamOpen(to, from, id, lang);
     }
@@ -720,6 +715,11 @@ public final class ModularXmppClientToServerConnection extends AbstractXMPPConne
                 throw SmackException.NoEndpointsDiscoveredException.from(lookupFailures);
             }
 
+            if (!lookupFailures.isEmpty()) {
+                // TODO: Put those non-fatal lookup failures into a sink of the connection so that the user is able to
+                // be aware of them.
+            }
+
             // Even though the outgoing elements queue is unrelated to the lookup remote connection endpoints state, we
             // do start the queue at this point. The transports will need it available, and we use the state's reset()
             // function to close the queue again on failure.
@@ -1110,7 +1110,12 @@ public final class ModularXmppClientToServerConnection extends AbstractXMPPConne
                 XmppClientToServerTransport.Stats stats = entry.getValue();
 
                 StringUtils.appendHeading(appendable, transportClass.getName());
-                appendable.append(stats.toString()).append('\n');
+                if (stats != null) {
+                    appendable.append(stats.toString());
+                } else {
+                    appendable.append("No stats available.");
+                }
+                appendable.append('\n');
             }
 
             for (Map.Entry<String, Object> entry : filtersStats.entrySet()) {

smack-core/src/main/java/org/jivesoftware/smack/c2s/ModularXmppClientToServerConnectionConfiguration.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2019-2020 Florian Schmaus
+ * Copyright 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.
@@ -62,6 +62,10 @@ public final class ModularXmppClientToServerConnectionConfiguration extends Conn
             // configuration, e.g. there is no edge from disconnected to connected.
             throw new IllegalStateException(e);
         }
+
+        for (ModularXmppClientToServerConnectionModuleDescriptor moduleDescriptor : moduleDescriptors) {
+            moduleDescriptor.validateConfiguration(this);
+        }
     }
 
     public void printStateGraphInDotFormat(PrintWriter pw, boolean breakStateName) {

smack-core/src/main/java/org/jivesoftware/smack/c2s/ModularXmppClientToServerConnectionModuleDescriptor.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2019-2020 Florian Schmaus
+ * Copyright 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.
@@ -28,6 +28,9 @@ public abstract class ModularXmppClientToServerConnectionModuleDescriptor {
     protected abstract ModularXmppClientToServerConnectionModule<? extends ModularXmppClientToServerConnectionModuleDescriptor> constructXmppConnectionModule(
                     ModularXmppClientToServerConnectionInternal connectionInternal);
 
+    protected void validateConfiguration(ModularXmppClientToServerConnectionConfiguration configuration) {
+    }
+
     public abstract static class Builder {
         private final ModularXmppClientToServerConnectionConfiguration.Builder connectionConfigurationBuilder;
 

smack-core/src/main/java/org/jivesoftware/smack/c2s/StreamOpenAndCloseFactory.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.
@@ -19,8 +19,12 @@ package org.jivesoftware.smack.c2s;
 import org.jivesoftware.smack.packet.AbstractStreamClose;
 import org.jivesoftware.smack.packet.AbstractStreamOpen;
 
+import org.jxmpp.jid.DomainBareJid;
+
 public interface StreamOpenAndCloseFactory {
-    AbstractStreamOpen createStreamOpen(CharSequence to, CharSequence from, String id, String lang);
+
+    AbstractStreamOpen createStreamOpen(DomainBareJid to, CharSequence from, String id, String lang);
 
     AbstractStreamClose createStreamClose();
+
 }

smack-core/src/main/java/org/jivesoftware/smack/c2s/XmppClientToServerTransport.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2019-2020 Florian Schmaus
+ * Copyright 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.
@@ -37,6 +37,8 @@ public abstract class XmppClientToServerTransport {
 
     protected abstract void loadConnectionEndpoints(LookupConnectionEndpointsSuccess lookupConnectionEndpointsSuccess);
 
+    public abstract boolean hasUseableConnectionEndpoints();
+
     /**
      * Notify the transport that new outgoing data is available. Usually this method does not need to be called
      * explicitly, only if the filters are modified so that they potentially produced new data.

smack-core/src/main/java/org/jivesoftware/smack/c2s/internal/ModularXmppClientToServerConnectionInternal.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.
@@ -16,6 +16,7 @@
  */
 package org.jivesoftware.smack.c2s.internal;
 
+import java.io.IOException;
 import java.nio.channels.ClosedChannelException;
 import java.nio.channels.SelectableChannel;
 import java.nio.channels.SelectionKey;
@@ -39,8 +40,10 @@ import org.jivesoftware.smack.packet.Nonza;
 import org.jivesoftware.smack.packet.TopLevelStreamElement;
 import org.jivesoftware.smack.packet.XmlEnvironment;
 import org.jivesoftware.smack.util.Consumer;
+import org.jivesoftware.smack.util.PacketParserUtils;
 import org.jivesoftware.smack.util.Supplier;
 import org.jivesoftware.smack.xml.XmlPullParser;
+import org.jivesoftware.smack.xml.XmlPullParserException;
 
 public abstract class ModularXmppClientToServerConnectionInternal {
 
@@ -85,9 +88,19 @@ public abstract class ModularXmppClientToServerConnectionInternal {
 
     public abstract void notifyConnectionError(Exception e);
 
-    public abstract void setCurrentConnectionExceptionAndNotify(Exception exception);
+    public final String onStreamOpen(String streamOpen) {
+        XmlPullParser streamOpenParser;
+        try {
+            streamOpenParser = PacketParserUtils.getParserFor(streamOpen);
+        } catch (XmlPullParserException | IOException e) {
+            // Should never happen.
+            throw new AssertionError(e);
+        }
+        String streamClose = onStreamOpen(streamOpenParser);
+        return streamClose;
+    }
 
-    public abstract void onStreamOpen(XmlPullParser parser);
+    public abstract String onStreamOpen(XmlPullParser parser);
 
     public abstract void onStreamClosed();
 

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

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2018-2020 Florian Schmaus
+ * Copyright 2018-2021 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 @@ import java.io.IOException;
 
 import org.jivesoftware.smack.SmackException;
 import org.jivesoftware.smack.XMPPException;
+import org.jivesoftware.smack.c2s.XmppClientToServerTransport;
 import org.jivesoftware.smack.c2s.internal.ModularXmppClientToServerConnectionInternal;
 import org.jivesoftware.smack.c2s.internal.WalkStateGraphContext;
 
@@ -75,4 +76,24 @@ public abstract class State {
         }
     }
 
+    public abstract static class AbstractTransport extends State {
+
+        private final XmppClientToServerTransport transport;
+
+        protected AbstractTransport(XmppClientToServerTransport transport, StateDescriptor stateDescriptor,
+                        ModularXmppClientToServerConnectionInternal connectionInternal) {
+            super(stateDescriptor, connectionInternal);
+            this.transport = transport;
+        }
+
+        @Override
+        public StateTransitionResult.TransitionImpossible isTransitionToPossible(WalkStateGraphContext walkStateGraphContext)
+                        throws SmackException {
+            if (!transport.hasUseableConnectionEndpoints()) {
+                return new StateTransitionResult.TransitionImpossibleBecauseNoEndpointsDiscovered(transport);
+            }
+
+            return super.isTransitionToPossible(walkStateGraphContext);
+        }
+    }
 }

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

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2018-2020 Florian Schmaus
+ * Copyright 2018-2021 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,6 +16,8 @@
  */
 package org.jivesoftware.smack.fsm;
 
+import org.jivesoftware.smack.c2s.XmppClientToServerTransport;
+
 public abstract class StateTransitionResult {
 
     private final String message;
@@ -92,4 +94,10 @@ public abstract class StateTransitionResult {
             super(stateDescriptor.getFullStateName(false) + " is not implemented (yet)");
         }
     }
+
+    public static class TransitionImpossibleBecauseNoEndpointsDiscovered extends TransitionImpossibleReason {
+        public TransitionImpossibleBecauseNoEndpointsDiscovered(XmppClientToServerTransport transport) {
+            super("The transport " + transport + " did not discover any endpoints");
+        }
+    }
 }

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

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2020 Florian Schmaus, Aditya Borikar
+ * Copyright 2020-2021 Florian Schmaus, 2020 Aditya Borikar
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -28,6 +28,7 @@ import org.jivesoftware.smack.util.XmlStringBuilder;
  * be achieved through {@link XMPPConnection#sendNonza(Nonza)}.
  */
 public abstract class AbstractStreamOpen implements Nonza {
+    public static final String ETHERX_JABBER_STREAMS_NAMESPACE = "http://etherx.jabber.org/streams";
     public static final String CLIENT_NAMESPACE = "jabber:client";
     public static final String SERVER_NAMESPACE = "jabber:server";
 

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

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2018 Florian Schmaus
+ * Copyright 2018-2021 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 +20,8 @@ public final class StreamClose extends AbstractStreamClose {
 
     public static final StreamClose INSTANCE = new StreamClose();
 
+    public static final String STRING = "</" + StreamOpen.ELEMENT + ">";
+
     private StreamClose() {
     }
 
@@ -39,4 +41,8 @@ public final class StreamClose extends AbstractStreamClose {
         return StreamOpen.ELEMENT;
     }
 
+    @Override
+    public String toString() {
+        return STRING;
+    }
 }

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

@@ -23,7 +23,9 @@ import org.jivesoftware.smack.util.XmlStringBuilder;
  * The stream open <b>tag</b>.
  */
 public final class StreamOpen extends AbstractStreamOpen {
-    public static final String ELEMENT = "stream:stream";
+    public static final String UNPREFIXED_ELEMENT = "stream";
+
+    public static final String ELEMENT = "stream:" + UNPREFIXED_ELEMENT;
 
     public StreamOpen(CharSequence to) {
        this(to, null, null, null, StreamContentNamespace.client);

smack-java8-full/build.gradle

@@ -12,7 +12,8 @@ dependencies {
 	api project(':smack-openpgp')
 	api project(':smack-resolver-minidns')
 	api project(':smack-resolver-minidns-dox')
-	api project(':smack-websocket')
+	// TODO: Change this to smack-websocket-java11 once it arrives.
+	api project(':smack-websocket-okhttp')
 	api project(':smack-tcp')
 
 	testImplementation(testFixtures(project(":smack-core")))

smack-java8-full/src/main/java/org/jivesoftware/smack/full/WebSocketConnectionTest.java

@@ -0,0 +1,110 @@
+/**
+ *
+ * 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.full;
+
+import java.io.IOException;
+import java.net.URISyntaxException;
+import java.util.Date;
+import java.util.logging.Logger;
+
+import org.jivesoftware.smack.SmackConfiguration;
+import org.jivesoftware.smack.SmackException;
+import org.jivesoftware.smack.XMPPException;
+
+import org.jivesoftware.smack.c2s.ModularXmppClientToServerConnection;
+import org.jivesoftware.smack.c2s.ModularXmppClientToServerConnectionConfiguration;
+import org.jivesoftware.smack.debugger.ConsoleDebugger;
+import org.jivesoftware.smack.packet.Message;
+import org.jivesoftware.smack.websocket.XmppWebSocketTransportModuleDescriptor;
+import org.jivesoftware.smackx.disco.ServiceDiscoveryManager;
+
+import org.jxmpp.util.XmppDateTime;
+
+public class WebSocketConnectionTest {
+
+    static {
+        SmackConfiguration.DEBUG = true;
+    }
+
+    public static void main(String[] args)
+                    throws URISyntaxException, SmackException, IOException, XMPPException, InterruptedException {
+        String jid, password, websocketEndpoint, messageTo = null;
+        if (args.length < 3 || args.length > 4) {
+            throw new IllegalArgumentException();
+        }
+
+        jid = args[0];
+        password = args[1];
+        websocketEndpoint = args[2];
+        if (args.length >= 4) {
+            messageTo = args[3];
+        }
+
+        testWebSocketConnection(jid, password, websocketEndpoint, messageTo);
+    }
+
+    public static void testWebSocketConnection(String jid, String password, String websocketEndpoint)
+                    throws URISyntaxException, SmackException, IOException, XMPPException, InterruptedException {
+        testWebSocketConnection(jid, password, websocketEndpoint, null);
+    }
+
+    public static void testWebSocketConnection(String jid, String password, String websocketEndpoint, String messageTo)
+                    throws URISyntaxException, SmackException, IOException, XMPPException, InterruptedException {
+        ModularXmppClientToServerConnectionConfiguration.Builder builder = ModularXmppClientToServerConnectionConfiguration.builder();
+        builder.removeAllModules()
+               .setXmppAddressAndPassword(jid, password)
+               .setDebuggerFactory(ConsoleDebugger.Factory.INSTANCE)
+               ;
+
+        XmppWebSocketTransportModuleDescriptor.Builder websocketBuilder = XmppWebSocketTransportModuleDescriptor.getBuilder(builder);
+        websocketBuilder.explicitlySetWebSocketEndpointAndDiscovery(websocketEndpoint, false);
+        builder.addModule(websocketBuilder.build());
+
+        ModularXmppClientToServerConnectionConfiguration config = builder.build();
+        ModularXmppClientToServerConnection connection = new ModularXmppClientToServerConnection(config);
+
+        connection.setReplyTimeout(5 * 60 * 1000);
+
+        connection.addConnectionStateMachineListener((event, c) -> {
+            Logger.getAnonymousLogger().info("Connection event: " + event);
+        });
+
+        connection.connect();
+
+        connection.login();
+
+        if (messageTo != null) {
+            Message message = connection.getStanzaFactory().buildMessageStanza()
+                    .to(messageTo)
+                    .setBody("It is alive! " + XmppDateTime.formatXEP0082Date(new Date()))
+                    .build()
+                    ;
+            connection.sendStanza(message);
+        }
+
+        Thread.sleep(1000);
+
+        connection.disconnect();
+
+        ModularXmppClientToServerConnection.Stats connectionStats = connection.getStats();
+        ServiceDiscoveryManager.Stats serviceDiscoveryManagerStats = ServiceDiscoveryManager.getInstanceFor(connection).getStats();
+
+        // CHECKSTYLE:OFF
+        System.out.println("WebSocket successfully finished, yeah!\n" + connectionStats + '\n' + serviceDiscoveryManagerStats);
+        // CHECKSTYLE:ON
+    }
+}

smack-repl/src/main/java/org/igniterealtime/smack/smackrepl/Nio.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2018-2020 Florian Schmaus
+ * Copyright 2018-2021 Florian Schmaus
  *
  * This file is part of smack-repl.
  *
@@ -25,8 +25,6 @@ import java.io.IOException;
 import java.io.OutputStreamWriter;
 import java.io.PrintWriter;
 import java.nio.charset.StandardCharsets;
-import java.util.Date;
-import java.util.logging.Logger;
 
 import org.jivesoftware.smack.ConnectionConfiguration.SecurityMode;
 import org.jivesoftware.smack.SmackException;
@@ -38,18 +36,11 @@ import org.jivesoftware.smack.compression.XMPPInputOutputStream;
 import org.jivesoftware.smack.compression.XMPPInputOutputStream.FlushMethod;
 import org.jivesoftware.smack.debugger.ConsoleDebugger;
 import org.jivesoftware.smack.debugger.SmackDebuggerFactory;
-import org.jivesoftware.smack.packet.Message;
 import org.jivesoftware.smack.sm.StreamManagementModuleDescriptor;
 import org.jivesoftware.smack.tcp.XmppTcpTransportModuleDescriptor;
 
-import org.jivesoftware.smackx.disco.ServiceDiscoveryManager;
-
-import org.jxmpp.util.XmppDateTime;
-
 public class Nio {
 
-    private static final Logger LOGGER = Logger.getLogger(Nio.class.getName());
-
     public static void main(String[] args) throws SmackException, IOException, XMPPException, InterruptedException {
         doNio(args[0], args[1], args[2]);
     }
@@ -111,30 +102,7 @@ public class Nio {
 
         connection.setReplyTimeout(5 * 60 * 1000);
 
-        connection.addConnectionStateMachineListener((event, c) -> {
+        XmppTools.modularConnectionTest(connection, "flo@geekplace.eu");
-            LOGGER.info("Connection event: " + event);
-        });
-
-        connection.connect();
-
-        connection.login();
-
-        Message message = connection.getStanzaFactory().buildMessageStanza()
-                .to("flo@geekplace.eu")
-                .setBody("It is alive! " + XmppDateTime.formatXEP0082Date(new Date()))
-                .build();
-        connection.sendStanza(message);
-
-        Thread.sleep(1000);
-
-        connection.disconnect();
-
-        ModularXmppClientToServerConnection.Stats connectionStats = connection.getStats();
-        ServiceDiscoveryManager.Stats serviceDiscoveryManagerStats = ServiceDiscoveryManager.getInstanceFor(connection).getStats();
-
-        // CHECKSTYLE:OFF
-        System.out.println("NIO successfully finished, yeah!\n" + connectionStats + '\n' + serviceDiscoveryManagerStats);
-        // CHECKSTYLE:ON
     }
 
 }

smack-repl/src/main/java/org/igniterealtime/smack/smackrepl/WebSocketConnection.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2020 Aditya Borikar
+ * Copyright 2021 Florian Schmaus
  *
  * This file is part of smack-repl.
  *
@@ -21,7 +21,6 @@
 package org.igniterealtime.smack.smackrepl;
 
 import java.io.IOException;
-import java.net.URI;
 import java.net.URISyntaxException;
 
 import org.jivesoftware.smack.SmackException;
@@ -29,25 +28,51 @@ import org.jivesoftware.smack.XMPPException;
 
 import org.jivesoftware.smack.c2s.ModularXmppClientToServerConnection;
 import org.jivesoftware.smack.c2s.ModularXmppClientToServerConnectionConfiguration;
+import org.jivesoftware.smack.util.TLSUtils;
 import org.jivesoftware.smack.websocket.XmppWebSocketTransportModuleDescriptor;
 
 public class WebSocketConnection {
 
-    public static void main(String[] args) throws SmackException, IOException, XMPPException, InterruptedException, URISyntaxException {
+    public static void main(String[] args)
-        ModularXmppClientToServerConnectionConfiguration.Builder builder = ModularXmppClientToServerConnectionConfiguration.builder();
+                    throws URISyntaxException, SmackException, IOException, XMPPException, InterruptedException {
-        builder.removeAllModules();
+        String jid, password, websocketEndpoint, messageTo = null;
-        builder.setXmppAddressAndPassword(args[0], args[1]);
+        if (args.length < 3 || args.length > 4) {
+            throw new IllegalArgumentException();
+        }
+
+        jid = args[0];
+        password = args[1];
+        websocketEndpoint = args[2];
+        if (args.length >= 4) {
+            messageTo = args[3];
+        }
+
+        TLSUtils.setDefaultTrustStoreTypeToJksIfRequired();
+
+        testWebSocketConnection(jid, password, websocketEndpoint, messageTo);
+    }
+
+    public static void testWebSocketConnection(String jid, String password, String websocketEndpoint)
+                    throws URISyntaxException, SmackException, IOException, XMPPException, InterruptedException {
+        testWebSocketConnection(jid, password, websocketEndpoint, null);
+    }
+
+    public static void testWebSocketConnection(String jid, String password, String websocketEndpoint, String messageTo)
+                    throws URISyntaxException, SmackException, IOException, XMPPException, InterruptedException {
+        ModularXmppClientToServerConnectionConfiguration.Builder builder = ModularXmppClientToServerConnectionConfiguration.builder();
+        builder.removeAllModules()
+               .setXmppAddressAndPassword(jid, password)
+               ;
 
-        // Set a fallback uri into websocket transport descriptor and add this descriptor into connection builder.
         XmppWebSocketTransportModuleDescriptor.Builder websocketBuilder = XmppWebSocketTransportModuleDescriptor.getBuilder(builder);
-        websocketBuilder.explicitlySetWebSocketEndpointAndDiscovery(new URI(args[2]), false);
+        websocketBuilder.explicitlySetWebSocketEndpointAndDiscovery(websocketEndpoint, false);
         builder.addModule(websocketBuilder.build());
 
         ModularXmppClientToServerConnectionConfiguration config = builder.build();
         ModularXmppClientToServerConnection connection = new ModularXmppClientToServerConnection(config);
 
-        connection.connect();
+        connection.setReplyTimeout(5 * 60 * 1000);
-        connection.login();
+
-        connection.disconnect();
+        XmppTools.modularConnectionTest(connection, messageTo);
     }
 }

smack-repl/src/main/java/org/igniterealtime/smack/smackrepl/XmppTools.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2016 Florian Schmaus
+ * Copyright 2016-2021 Florian Schmaus
  *
  * This file is part of smack-repl.
  *
@@ -23,6 +23,8 @@ package org.igniterealtime.smack.smackrepl;
 import java.io.IOException;
 import java.security.KeyManagementException;
 import java.security.NoSuchAlgorithmException;
+import java.util.Date;
+import java.util.logging.Logger;
 
 import org.jivesoftware.smack.SmackException;
 import org.jivesoftware.smack.SmackException.NoResponseException;
@@ -30,15 +32,19 @@ import org.jivesoftware.smack.SmackException.NotConnectedException;
 import org.jivesoftware.smack.XMPPConnection;
 import org.jivesoftware.smack.XMPPException;
 import org.jivesoftware.smack.XMPPException.XMPPErrorException;
+import org.jivesoftware.smack.c2s.ModularXmppClientToServerConnection;
+import org.jivesoftware.smack.packet.Message;
 import org.jivesoftware.smack.tcp.XMPPTCPConnection;
 import org.jivesoftware.smack.tcp.XMPPTCPConnectionConfiguration;
 import org.jivesoftware.smack.util.TLSUtils;
-
+import org.jivesoftware.smackx.disco.ServiceDiscoveryManager;
 import org.jivesoftware.smackx.iqregister.AccountManager;
 
 import org.jxmpp.jid.DomainBareJid;
 import org.jxmpp.jid.impl.JidCreate;
 import org.jxmpp.jid.parts.Localpart;
+import org.jxmpp.stringprep.XmppStringprepException;
+import org.jxmpp.util.XmppDateTime;
 
 public class XmppTools {
 
@@ -106,4 +112,40 @@ public class XmppTools {
             connection.disconnect();
         }
     }
+
+    public static void modularConnectionTest(ModularXmppClientToServerConnection connection, String messageTo) throws XMPPException, SmackException, IOException, InterruptedException {
+        connection.addConnectionStateMachineListener((event, c) -> {
+            Logger.getAnonymousLogger().info("Connection event: " + event);
+        });
+
+        connection.connect();
+
+        connection.login();
+
+        XmppTools.sendItsAlive(messageTo, connection);
+
+        Thread.sleep(1000);
+
+        connection.disconnect();
+
+        ModularXmppClientToServerConnection.Stats connectionStats = connection.getStats();
+        ServiceDiscoveryManager.Stats serviceDiscoveryManagerStats = ServiceDiscoveryManager.getInstanceFor(connection).getStats();
+
+        // CHECKSTYLE:OFF
+        System.out.println("NIO successfully finished, yeah!\n" + connectionStats + '\n' + serviceDiscoveryManagerStats);
+        // CHECKSTYLE:ON
+    }
+
+    public static void sendItsAlive(String to, XMPPConnection connection)
+                    throws XmppStringprepException, NotConnectedException, InterruptedException {
+        if (to == null) {
+            return;
+        }
+
+        Message message = connection.getStanzaFactory().buildMessageStanza()
+                        .to(to)
+                        .setBody("It is alive! " + XmppDateTime.formatXEP0082Date(new Date()))
+                        .build();
+        connection.sendStanza(message);
+    }
 }

smack-tcp/src/main/java/org/jivesoftware/smack/tcp/XMPPTCPConnection.java

@@ -83,6 +83,7 @@ import org.jivesoftware.smack.packet.Presence;
 import org.jivesoftware.smack.packet.Stanza;
 import org.jivesoftware.smack.packet.StartTls;
 import org.jivesoftware.smack.packet.StreamError;
+import org.jivesoftware.smack.packet.StreamOpen;
 import org.jivesoftware.smack.proxy.ProxyInfo;
 import org.jivesoftware.smack.sasl.packet.SaslNonza;
 import org.jivesoftware.smack.sm.SMUtils;
@@ -961,6 +962,8 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
                     switch (eventType) {
                     case START_ELEMENT:
                         final String name = parser.getName();
+                        final String namespace = parser.getNamespace();
+
                         switch (name) {
                         case Message.ELEMENT:
                         case IQ.IQ_ELEMENT:
@@ -972,7 +975,9 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
                             }
                             break;
                         case "stream":
+                            if (StreamOpen.ETHERX_JABBER_STREAMS_NAMESPACE.equals(namespace)) {
                                 onStreamOpen(parser);
+                            }
                             break;
                         case "error":
                             StreamError streamError = PacketParserUtils.parseStreamError(parser);
@@ -989,7 +994,6 @@ public class XMPPTCPConnection extends AbstractXMPPConnection {
                             openStreamAndResetParser();
                             break;
                         case "failure":
-                            String namespace = parser.getNamespace(null);
                             switch (namespace) {
                             case "urn:ietf:params:xml:ns:xmpp-tls":
                                 // TLS negotiation has failed. The server will close the connection

smack-tcp/src/main/java/org/jivesoftware/smack/tcp/XmppTcpTransportModule.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2019-2020 Florian Schmaus
+ * Copyright 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.
@@ -80,14 +80,12 @@ import org.jivesoftware.smack.tcp.rce.RemoteXmppTcpConnectionEndpoints;
 import org.jivesoftware.smack.tcp.rce.RemoteXmppTcpConnectionEndpoints.Result;
 import org.jivesoftware.smack.tcp.rce.Rfc6120TcpRemoteConnectionEndpoint;
 import org.jivesoftware.smack.util.CollectionUtil;
-import org.jivesoftware.smack.util.PacketParserUtils;
 import org.jivesoftware.smack.util.StringUtils;
 import org.jivesoftware.smack.util.UTF8;
 import org.jivesoftware.smack.util.XmlStringBuilder;
 import org.jivesoftware.smack.util.rce.RemoteConnectionEndpointLookupFailure;
-import org.jivesoftware.smack.xml.XmlPullParser;
-import org.jivesoftware.smack.xml.XmlPullParserException;
 
+import org.jxmpp.jid.DomainBareJid;
 import org.jxmpp.jid.Jid;
 import org.jxmpp.jid.util.JidUtil;
 import org.jxmpp.xml.splitter.Utf8ByteXmppXmlSplitter;
@@ -213,6 +211,8 @@ public class XmppTcpTransportModule extends ModularXmppClientToServerConnectionM
             }
 
             final String prefixXmlns = "xmlns:" + prefix;
+            // TODO: Use the return value of onStreamOpen(), which now returns the
+            // corresponding stream close tag, instead of creating it here.
             final StringBuilder streamClose = new StringBuilder(32);
             final StringBuilder streamOpen = new StringBuilder(256);
 
@@ -253,14 +253,7 @@ public class XmppTcpTransportModule extends ModularXmppClientToServerConnectionM
             this.streamOpen = streamOpen.toString();
             this.streamClose = streamClose.toString();
 
-            XmlPullParser streamOpenParser;
+            connectionInternal.onStreamOpen(this.streamOpen);
-            try {
-                streamOpenParser = PacketParserUtils.getParserFor(this.streamOpen);
-            } catch (XmlPullParserException | IOException e) {
-                // Should never happen.
-                throw new AssertionError(e);
-            }
-            connectionInternal.onStreamOpen(streamOpenParser);
         }
 
         @Override
@@ -586,7 +579,7 @@ public class XmppTcpTransportModule extends ModularXmppClientToServerConnectionM
         public StreamOpenAndCloseFactory getStreamOpenAndCloseFactory() {
             return new StreamOpenAndCloseFactory() {
                 @Override
-                public StreamOpen createStreamOpen(CharSequence to, CharSequence from, String id, String lang) {
+                public StreamOpen createStreamOpen(DomainBareJid to, CharSequence from, String id, String lang) {
                     String xmlLang = connectionInternal.connection.getConfiguration().getXmlLang();
                     StreamOpen streamOpen = new StreamOpen(to, from, id, xmlLang, StreamOpen.StreamContentNamespace.client);
                     return streamOpen;
@@ -603,6 +596,11 @@ public class XmppTcpTransportModule extends ModularXmppClientToServerConnectionM
             discoveredTcpEndpoints = null;
         }
 
+        @Override
+        public boolean hasUseableConnectionEndpoints() {
+            return discoveredTcpEndpoints != null;
+        }
+
         @Override
         protected List<SmackFuture<LookupConnectionEndpointsResult, Exception>> lookupConnectionEndpoints() {
             // Assert that there are no stale discovered endpoints prior performing the lookup.
@@ -750,10 +748,10 @@ public class XmppTcpTransportModule extends ModularXmppClientToServerConnectionM
         return new EstablishingTcpConnectionState(stateDescriptor, connectionInternal);
     }
 
-    final class EstablishingTcpConnectionState extends State {
+    final class EstablishingTcpConnectionState extends State.AbstractTransport {
         private EstablishingTcpConnectionState(EstablishingTcpConnectionStateDescriptor stateDescriptor,
                         ModularXmppClientToServerConnectionInternal connectionInternal) {
-            super(stateDescriptor, connectionInternal);
+            super(tcpNioTransport, stateDescriptor, connectionInternal);
         }
 
         @Override
@@ -777,6 +775,10 @@ public class XmppTcpTransportModule extends ModularXmppClientToServerConnectionM
 
             connectionInternal.setTransport(tcpNioTransport);
 
+            // TODO: It appears this should be done in a generic way. I'd assume we always
+            // have to wait for stream features after the connection was established. If this is true then consider
+            // moving this into State.AbstractTransport. But I am not yet 100% positive that this is the case for every
+            // transport. Hence keep it here for now.
             connectionInternal.newStreamOpenWaitForFeaturesSequence("stream features after initial connection");
 
             return new TcpSocketConnectedResult(remoteAddress);

smack-websocket-okhttp/src/main/java/org/jivesoftware/smack/websocket/okhttp/LoggingInterceptor.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.
@@ -17,7 +17,6 @@
 package org.jivesoftware.smack.websocket.okhttp;
 
 import java.io.IOException;
-import java.nio.charset.Charset;
 import java.util.Iterator;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -27,39 +26,34 @@ import org.jivesoftware.smack.debugger.SmackDebugger;
 import okhttp3.Headers;
 import okhttp3.Response;
 
-import org.jxmpp.xml.splitter.Utf8ByteXmppXmlSplitter;
 import org.jxmpp.xml.splitter.XmlPrettyPrinter;
 import org.jxmpp.xml.splitter.XmppXmlSplitter;
 
 public final class LoggingInterceptor {
-    private static final Logger LOGGER = Logger.getAnonymousLogger();
+    private static final Logger LOGGER = Logger.getLogger(LoggingInterceptor.class.getName());
-    private static final int MAX_ELEMENT_SIZE = 64 * 1024;
-    private final SmackDebugger debugger;
-    private final Utf8ByteXmppXmlSplitter incomingTextSplitter;
-    private final Utf8ByteXmppXmlSplitter outgoingTextSplitter;
 
-    public LoggingInterceptor(SmackDebugger smackDebugger) {
+    private final SmackDebugger debugger;
+    private final XmppXmlSplitter incomingXmlSplitter;
+    private final XmppXmlSplitter outgoingXmlSplitter;
+
+    LoggingInterceptor(SmackDebugger smackDebugger) {
         this.debugger = smackDebugger;
 
         XmlPrettyPrinter incomingTextPrinter = XmlPrettyPrinter.builder()
                                     .setPrettyWriter(sb -> debugger.incomingStreamSink(sb))
                                     .setTabWidth(4)
                                     .build();
-        XmppXmlSplitter incomingXmlSplitter = new XmppXmlSplitter(MAX_ELEMENT_SIZE, null,
+        incomingXmlSplitter = new XmppXmlSplitter(incomingTextPrinter);
-                incomingTextPrinter);
-        incomingTextSplitter = new Utf8ByteXmppXmlSplitter(incomingXmlSplitter);
 
         XmlPrettyPrinter outgoingTextPrinter = XmlPrettyPrinter.builder()
                 .setPrettyWriter(sb -> debugger.outgoingStreamSink(sb))
                 .setTabWidth(4)
                 .build();
-        XmppXmlSplitter outgoingXmlSplitter = new XmppXmlSplitter(MAX_ELEMENT_SIZE, null,
+        outgoingXmlSplitter = new XmppXmlSplitter(outgoingTextPrinter);
-                outgoingTextPrinter);
-        outgoingTextSplitter = new Utf8ByteXmppXmlSplitter(outgoingXmlSplitter);
     }
 
     // Open response received here isn't in the form of an Xml an so, there isn't much to format.
-    public void interceptOpenResponse(Response response) {
+    void interceptOpenResponse(Response response) {
        Headers headers = response.headers();
        Iterator<?> iterator = headers.iterator();
        StringBuilder sb = new StringBuilder();
@@ -70,18 +64,18 @@ public final class LoggingInterceptor {
        debugger.incomingStreamSink(sb);
     }
 
-    public void interceptReceivedText(String text) {
+    void interceptReceivedText(String text) {
         try {
-            incomingTextSplitter.write(text.getBytes(Charset.defaultCharset()));
+            incomingXmlSplitter.write(text);
         } catch (IOException e) {
             // Connections shouldn't be terminated due to exceptions encountered during debugging. hence only log them.
             LOGGER.log(Level.WARNING, "IOException encountered while parsing received text: " + text, e);
         }
     }
 
-    public void interceptSentText(String text) {
+    void interceptSentText(String text) {
         try {
-            outgoingTextSplitter.write(text.getBytes(Charset.defaultCharset()));
+            outgoingXmlSplitter.write(text);
         } catch (IOException e) {
             // Connections shouldn't be terminated due to exceptions encountered during debugging, hence only log them.
             LOGGER.log(Level.WARNING, "IOException encountered while parsing outgoing text: " + text, e);

smack-websocket-okhttp/src/main/java/org/jivesoftware/smack/websocket/okhttp/OkHttpWebSocket.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2020 Aditya Borikar
+ * Copyright 2020 Aditya Borikar, 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.
@@ -16,22 +16,17 @@
  */
 package org.jivesoftware.smack.websocket.okhttp;
 
-import java.io.IOException;
+import java.net.URI;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
 import javax.net.ssl.SSLSession;
 
-import org.jivesoftware.smack.SmackException;
+import org.jivesoftware.smack.SmackFuture;
-import org.jivesoftware.smack.XMPPException;
 import org.jivesoftware.smack.c2s.internal.ModularXmppClientToServerConnectionInternal;
-import org.jivesoftware.smack.packet.TopLevelStreamElement;
-import org.jivesoftware.smack.util.PacketParserUtils;
 import org.jivesoftware.smack.websocket.WebSocketException;
-import org.jivesoftware.smack.websocket.elements.WebSocketOpenElement;
 import org.jivesoftware.smack.websocket.impl.AbstractWebSocket;
 import org.jivesoftware.smack.websocket.rce.WebSocketRemoteConnectionEndpoint;
-import org.jivesoftware.smack.xml.XmlPullParserException;
 
 import okhttp3.OkHttpClient;
 import okhttp3.Request;
@@ -43,50 +38,49 @@ public final class OkHttpWebSocket extends AbstractWebSocket {
 
     private static final Logger LOGGER = Logger.getLogger(OkHttpWebSocket.class.getName());
 
-    private static OkHttpClient okHttpClient = null;
+    private static final OkHttpClient okHttpClient = new OkHttpClient();
+
+    // This is a potential candidate to be placed into AbstractWebSocket, but I keep it here until smack-websocket-java11
+    // arrives.
+    private final SmackFuture.InternalSmackFuture<AbstractWebSocket, Exception> future = new SmackFuture.InternalSmackFuture<>();
 
-    private final ModularXmppClientToServerConnectionInternal connectionInternal;
     private final LoggingInterceptor interceptor;
 
-    private String openStreamHeader;
+    private final WebSocket okHttpWebSocket;
-    private WebSocket currentWebSocket;
-    private WebSocketConnectionPhase phase;
-    private WebSocketRemoteConnectionEndpoint connectedEndpoint;
 
-    public OkHttpWebSocket(ModularXmppClientToServerConnectionInternal connectionInternal) {
+    public OkHttpWebSocket(WebSocketRemoteConnectionEndpoint endpoint,
-        this.connectionInternal = connectionInternal;
+                    ModularXmppClientToServerConnectionInternal connectionInternal) {
+        super(endpoint, connectionInternal);
 
-        if (okHttpClient == null) {
-            // Creates an instance of okHttp client.
-            OkHttpClient.Builder builder = new OkHttpClient.Builder();
-            okHttpClient = builder.build();
-        }
-        // Add some mechanism to enable and disable this interceptor.
         if (connectionInternal.smackDebugger != null) {
             interceptor = new LoggingInterceptor(connectionInternal.smackDebugger);
         } else {
             interceptor = null;
         }
-    }
 
-    @Override
+        final URI uri = endpoint.getUri();
-    public void connect(WebSocketRemoteConnectionEndpoint endpoint) throws InterruptedException, SmackException, XMPPException {
+        final String url = uri.toString();
-        final String currentUri = endpoint.getWebSocketEndpoint().toString();
+
         Request request = new Request.Builder()
-                              .url(currentUri)
+                              .url(url)
                               .header("Sec-WebSocket-Protocol", "xmpp")
                               .build();
 
-        WebSocketListener listener = new WebSocketListener() {
+        okHttpWebSocket = okHttpClient.newWebSocket(request, listener);
+    }
+
+    private final WebSocketListener listener = new WebSocketListener() {
 
         @Override
         public void onOpen(WebSocket webSocket, Response response) {
-                LOGGER.log(Level.FINER, "WebSocket is open");
+            LOGGER.log(Level.FINER, "OkHttp invoked onOpen() for {0}. Response: {1}",
-                phase = WebSocketConnectionPhase.openFrameSent;
+                            new Object[] { webSocket, response });
+
             if (interceptor != null) {
                 interceptor.interceptOpenResponse(response);
             }
-                send(new WebSocketOpenElement(connectionInternal.connection.getXMPPServiceDomain()));
+
+            future.setResult(OkHttpWebSocket.this);
         }
 
         @Override
@@ -94,84 +88,69 @@ public final class OkHttpWebSocket extends AbstractWebSocket {
             if (interceptor != null) {
                 interceptor.interceptReceivedText(text);
             }
-                if (isCloseElement(text)) {
-                    connectionInternal.onStreamClosed();
-                    return;
-                }
 
-                String closingStream = "</stream>";
+            onIncomingWebSocketElement(text);
-                switch (phase) {
-                case openFrameSent:
-                    if (isOpenElement(text)) {
-                        // Converts the <open> element received into <stream> element.
-                        openStreamHeader = getStreamFromOpenElement(text);
-                        phase = WebSocketConnectionPhase.exchangingTopLevelStreamElements;
-
-                        try {
-                            connectionInternal.onStreamOpen(PacketParserUtils.getParserFor(openStreamHeader));
-                        } catch (XmlPullParserException | IOException e) {
-                            LOGGER.log(Level.WARNING, "Exception caught:", e);
-                        }
-                    } else {
-                        LOGGER.log(Level.WARNING, "Unexpected Frame received", text);
-                    }
-                    break;
-                case exchangingTopLevelStreamElements:
-                    connectionInternal.parseAndProcessElement(openStreamHeader + text + closingStream);
-                    break;
-                default:
-                    LOGGER.log(Level.INFO, "Default text: " + text);
-                }
         }
 
         @Override
-            public void onFailure(WebSocket webSocket, Throwable t, Response response) {
+        public void onFailure(WebSocket webSocket, Throwable throwable, Response response) {
-                LOGGER.log(Level.INFO, "Exception caught", t);
+            LOGGER.log(Level.FINER, "OkHttp invoked onFailure() for " + webSocket + ". Response: " + response, throwable);
-                WebSocketException websocketException = new WebSocketException(t);
+            WebSocketException websocketException = new WebSocketException(throwable);
-                if (connectionInternal.connection.isConnected()) {
+
+            // If we are already connected, then we need to notify the connection that it got tear down. Otherwise we
+            // need to notify the thread calling connect() that the connection failed.
+            if (future.wasSuccessful()) {
                 connectionInternal.notifyConnectionError(websocketException);
             } else {
-                    connectionInternal.setCurrentConnectionExceptionAndNotify(websocketException);
+                future.setException(websocketException);
             }
         }
-        };
-
-        // Creates an instance of websocket through okHttpClient.
-        currentWebSocket = okHttpClient.newWebSocket(request, listener);
-
-        // Open a new stream and wait until features are received.
-        connectionInternal.waitForFeaturesReceived("Waiting to receive features");
-
-        connectedEndpoint = endpoint;
-    }
 
         @Override
-    public void send(TopLevelStreamElement element) {
+        public void onClosing(WebSocket webSocket, int code, String reason) {
-        String textToBeSent = element.toXML().toString();
+            LOGGER.log(Level.FINER, "OkHttp invoked onClosing() for " + webSocket + ". Code: " + code + ". Reason: " + reason);
-        if (interceptor != null) {
-            interceptor.interceptSentText(textToBeSent);
         }
-        currentWebSocket.send(textToBeSent);
+
+        @Override
+        public void onClosed(WebSocket webSocket, int code, String reason) {
+            LOGGER.log(Level.FINER, "OkHttp invoked onClosed() for " + webSocket + ". Code: " + code + ". Reason: " + reason);
+        }
+
+    };
+
+    @Override
+    public SmackFuture<AbstractWebSocket, Exception> getFuture() {
+        return future;
+    }
+
+    @Override
+    public void send(String element) {
+        if (interceptor != null) {
+            interceptor.interceptSentText(element);
+        }
+        okHttpWebSocket.send(element);
     }
 
     @Override
     public void disconnect(int code, String message) {
-        currentWebSocket.close(code, message);
+        LOGGER.log(Level.INFO, "WebSocket closing with code: " + code + " and message: " + message);
-        LOGGER.log(Level.INFO, "WebSocket has been closed with message: " + message);
+        okHttpWebSocket.close(code, message);
     }
 
     @Override
     public boolean isConnectionSecure() {
-        return connectedEndpoint.isSecureEndpoint();
+        return endpoint.isSecureEndpoint();
     }
 
     @Override
     public boolean isConnected() {
-        return connectedEndpoint == null ? false : true;
+        // TODO: Do we need this method at all if we create an AbstractWebSocket object for every endpoint?
+        return true;
     }
 
     @Override
     public SSLSession getSSLSession() {
+        // TODO: What shall we do about this method, as it appears that OkHttp does not provide access to the used SSLSession?
         return null;
     }
 }

smack-websocket-okhttp/src/main/java/org/jivesoftware/smack/websocket/okhttp/OkHttpWebSocketFactory.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.
@@ -19,12 +19,13 @@ package org.jivesoftware.smack.websocket.okhttp;
 import org.jivesoftware.smack.c2s.internal.ModularXmppClientToServerConnectionInternal;
 import org.jivesoftware.smack.websocket.impl.AbstractWebSocket;
 import org.jivesoftware.smack.websocket.impl.WebSocketFactory;
+import org.jivesoftware.smack.websocket.rce.WebSocketRemoteConnectionEndpoint;
 
 public class OkHttpWebSocketFactory implements WebSocketFactory {
 
     @Override
-    public AbstractWebSocket create(ModularXmppClientToServerConnectionInternal connectionInternal) {
+    public AbstractWebSocket create(WebSocketRemoteConnectionEndpoint endpoint, ModularXmppClientToServerConnectionInternal connectionInternal) {
-        return new OkHttpWebSocket(connectionInternal);
+        return new OkHttpWebSocket(endpoint, connectionInternal);
     }
 
 }

smack-websocket-okhttp/src/test/java/org/jivesoftware/smack/websocket/okhttp/OkHttpWebSocketFactoryServiceTest.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.
@@ -16,6 +16,8 @@
  */
 package org.jivesoftware.smack.websocket.okhttp;
 
+import java.net.URISyntaxException;
+
 import org.jivesoftware.smack.websocket.test.WebSocketFactoryServiceTestUtil;
 
 import org.junit.jupiter.api.Test;
@@ -23,7 +25,7 @@ import org.junit.jupiter.api.Test;
 public class OkHttpWebSocketFactoryServiceTest {
 
     @Test
-    public void createWebSocketTest() {
+    public void createWebSocketTest() throws URISyntaxException {
         WebSocketFactoryServiceTestUtil.createWebSocketTest(OkHttpWebSocket.class);
     }
 

smack-websocket/src/main/java/org/jivesoftware/smack/websocket/WebSocketConnectionAttemptState.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2020 Aditya Borikar, Florian Schmaus.
+ * Copyright 2020 Aditya Borikar, 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.
@@ -19,22 +19,29 @@ package org.jivesoftware.smack.websocket;
 import java.util.ArrayList;
 import java.util.List;
 
+import org.jivesoftware.smack.ConnectionConfiguration.SecurityMode;
+import org.jivesoftware.smack.SmackFuture;
 import org.jivesoftware.smack.c2s.internal.ModularXmppClientToServerConnectionInternal;
+import org.jivesoftware.smack.fsm.StateTransitionResult;
+import org.jivesoftware.smack.util.StringUtils;
 import org.jivesoftware.smack.websocket.XmppWebSocketTransportModule.EstablishingWebSocketConnectionState;
 import org.jivesoftware.smack.websocket.impl.AbstractWebSocket;
 import org.jivesoftware.smack.websocket.impl.WebSocketFactoryService;
 import org.jivesoftware.smack.websocket.rce.WebSocketRemoteConnectionEndpoint;
+import org.jivesoftware.smack.websocket.rce.WebSocketRemoteConnectionEndpointLookup;
 
 public final class WebSocketConnectionAttemptState {
     private final ModularXmppClientToServerConnectionInternal connectionInternal;
     private final XmppWebSocketTransportModule.XmppWebSocketTransport.DiscoveredWebSocketEndpoints discoveredEndpoints;
 
-    private WebSocketRemoteConnectionEndpoint connectedEndpoint;
+    private AbstractWebSocket webSocket;
 
     WebSocketConnectionAttemptState(ModularXmppClientToServerConnectionInternal connectionInternal,
                     XmppWebSocketTransportModule.XmppWebSocketTransport.DiscoveredWebSocketEndpoints discoveredWebSocketEndpoints,
                     EstablishingWebSocketConnectionState establishingWebSocketConnectionState) {
         assert discoveredWebSocketEndpoints != null;
+        assert !discoveredWebSocketEndpoints.result.isEmpty();
+
         this.connectionInternal = connectionInternal;
         this.discoveredEndpoints = discoveredWebSocketEndpoints;
     }
@@ -44,48 +51,96 @@ public final class WebSocketConnectionAttemptState {
      *
      * @return {@link AbstractWebSocket} with which connection is establised
      * @throws InterruptedException if the calling thread was interrupted
-     * @throws WebSocketException if encounters a websocket exception
      */
-    AbstractWebSocket establishWebSocketConnection() throws InterruptedException, WebSocketException {
+    @SuppressWarnings({"incomplete-switch", "MissingCasesInEnumSwitch"})
-        List<WebSocketRemoteConnectionEndpoint> endpoints = discoveredEndpoints.result.discoveredRemoteConnectionEndpoints;
+    StateTransitionResult.Failure establishWebSocketConnection() throws InterruptedException {
+        final WebSocketRemoteConnectionEndpointLookup.Result endpointLookupResult = discoveredEndpoints.result;
+        final List<Exception> failures = new ArrayList<>(endpointLookupResult.discoveredEndpointCount());
 
-        if (endpoints.isEmpty()) {
+        webSocket = null;
-            throw new WebSocketException(new Throwable("No Endpoints discovered to establish connection"));
-        }
 
-        List<Throwable> connectionFailureList = new ArrayList<>();
+        SecurityMode securityMode = connectionInternal.connection.getConfiguration().getSecurityMode();
-        AbstractWebSocket websocket = WebSocketFactoryService.createWebSocket(connectionInternal);
+        switch (securityMode) {
-
+        case required:
-        // Keep iterating over available endpoints until a connection is establised or all endpoints are tried to create a connection with.
+        case ifpossible:
-        for (WebSocketRemoteConnectionEndpoint endpoint : endpoints) {
+            establishWebSocketConnection(endpointLookupResult.discoveredSecureEndpoints, failures);
-            try {
+            if (webSocket != null) {
-                websocket.connect(endpoint);
+                return null;
-                connectedEndpoint = endpoint;
-                break;
-            } catch (Throwable t) {
-                connectionFailureList.add(t);
-
-                // If the number of entries in connectionFailureList is equal to the number of endpoints,
-                // it means that all endpoints have been tried and have been unsuccessful.
-                if (connectionFailureList.size() == endpoints.size()) {
-                    WebSocketException websocketException = new WebSocketException(connectionFailureList);
-                    throw new WebSocketException(websocketException);
             }
         }
+
+        establishWebSocketConnection(endpointLookupResult.discoveredInsecureEndpoints, failures);
+        if (webSocket != null) {
+            return null;
         }
 
-        assert connectedEndpoint != null;
+        StateTransitionResult.Failure failure = FailedToConnectToAnyWebSocketEndpoint.create(failures);
-
+        return failure;
-        // Return connected websocket when no failure occurs.
-        return websocket;
     }
 
-    /**
+    private void establishWebSocketConnection(List<? extends WebSocketRemoteConnectionEndpoint> webSocketEndpoints,
-     * Returns the connected websocket endpoint.
+                    List<Exception> failures) throws InterruptedException {
-     *
+        final int endpointCount = webSocketEndpoints.size();
-     * @return connected websocket endpoint
+
-     */
+        List<SmackFuture<AbstractWebSocket, Exception>> futures = new ArrayList<>(endpointCount);
-    public WebSocketRemoteConnectionEndpoint getConnectedEndpoint() {
+        {
-        return connectedEndpoint;
+            List<AbstractWebSocket> webSockets = new ArrayList<>(endpointCount);
+            // First only create the AbstractWebSocket instances, in case a constructor throws.
+            for (WebSocketRemoteConnectionEndpoint endpoint : webSocketEndpoints) {
+                AbstractWebSocket webSocket = WebSocketFactoryService.createWebSocket(endpoint, connectionInternal);
+                webSockets.add(webSocket);
+            }
+
+            for (AbstractWebSocket webSocket : webSockets) {
+                SmackFuture<AbstractWebSocket, Exception> future = webSocket.getFuture();
+                futures.add(future);
+            }
+        }
+
+        SmackFuture.await(futures, connectionInternal.connection.getReplyTimeout());
+
+        for (SmackFuture<AbstractWebSocket, Exception> future : futures) {
+            AbstractWebSocket connectedWebSocket = future.getIfAvailable();
+            if (connectedWebSocket == null) {
+                Exception exception = future.getExceptionIfAvailable();
+                assert exception != null;
+                failures.add(exception);
+                continue;
+            }
+
+            if (webSocket == null) {
+                webSocket = connectedWebSocket;
+                // Continue here since we still need to read out the failure exceptions from potential further remaining
+                // futures and close remaining successfully connected ones.
+                continue;
+            }
+
+            connectedWebSocket.disconnect(1000, "Using other connection endpoint at " + webSocket.getEndpoint());
+        }
+    }
+
+    public AbstractWebSocket getConnectedWebSocket() {
+        return webSocket;
+    }
+
+    public static final class FailedToConnectToAnyWebSocketEndpoint extends StateTransitionResult.Failure {
+
+        private final List<Exception> failures;
+
+        private FailedToConnectToAnyWebSocketEndpoint(String failureMessage, List<Exception> failures) {
+            super(failureMessage);
+            this.failures = failures;
+        }
+
+        public List<Exception> getFailures() {
+            return failures;
+        }
+
+        private static FailedToConnectToAnyWebSocketEndpoint create(List<Exception> failures) {
+            StringBuilder sb = new StringBuilder(256);
+            StringUtils.appendTo(failures, sb, e -> sb.append(e.getMessage()));
+            String message = sb.toString();
+            return new FailedToConnectToAnyWebSocketEndpoint(message, failures);
+        }
     }
 }

smack-websocket/src/main/java/org/jivesoftware/smack/websocket/WebSocketException.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2020 Aditya Borikar
+ * 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.
@@ -16,23 +16,11 @@
  */
 package org.jivesoftware.smack.websocket;
 
-import java.util.Collections;
-import java.util.List;
-
 public final class WebSocketException extends Exception {
     private static final long serialVersionUID = 1L;
 
-    private final List<Throwable> throwableList;
-
-    public WebSocketException(List<Throwable> throwableList) {
-        this.throwableList = throwableList;
-    }
-
     public WebSocketException(Throwable throwable) {
-        this.throwableList = Collections.singletonList(throwable);
+        super("WebSocketException: " + throwable.getMessage(), throwable);
     }
 
-    public List<Throwable> getThrowableList() {
-        return throwableList;
-    }
 }

smack-websocket/src/main/java/org/jivesoftware/smack/websocket/XmppWebSocketTransportModule.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2020 Aditya Borikar
+ * Copyright 2020 Aditya Borikar, 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.
@@ -16,20 +16,16 @@
  */
 package org.jivesoftware.smack.websocket;
 
-import java.io.IOException;
-import java.net.URI;
-import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.Queue;
-import java.util.logging.Level;
-import java.util.logging.Logger;
 
 import javax.net.ssl.SSLSession;
 
 import org.jivesoftware.smack.AsyncButOrdered;
-import org.jivesoftware.smack.ConnectionConfiguration.SecurityMode;
 import org.jivesoftware.smack.SmackException;
+import org.jivesoftware.smack.SmackException.NoResponseException;
+import org.jivesoftware.smack.SmackException.NotConnectedException;
 import org.jivesoftware.smack.SmackFuture;
 import org.jivesoftware.smack.SmackFuture.InternalSmackFuture;
 import org.jivesoftware.smack.XMPPException;
@@ -54,13 +50,13 @@ import org.jivesoftware.smack.websocket.XmppWebSocketTransportModule.XmppWebSock
 import org.jivesoftware.smack.websocket.elements.WebSocketCloseElement;
 import org.jivesoftware.smack.websocket.elements.WebSocketOpenElement;
 import org.jivesoftware.smack.websocket.impl.AbstractWebSocket;
+import org.jivesoftware.smack.websocket.rce.InsecureWebSocketRemoteConnectionEndpoint;
+import org.jivesoftware.smack.websocket.rce.SecureWebSocketRemoteConnectionEndpoint;
 import org.jivesoftware.smack.websocket.rce.WebSocketRemoteConnectionEndpoint;
 import org.jivesoftware.smack.websocket.rce.WebSocketRemoteConnectionEndpointLookup;
 import org.jivesoftware.smack.websocket.rce.WebSocketRemoteConnectionEndpointLookup.Result;
 
 import org.jxmpp.jid.DomainBareJid;
-import org.jxmpp.jid.impl.JidCreate;
-import org.jxmpp.stringprep.XmppStringprepException;
 
 /**
  * The websocket transport module that goes with Smack's modular architecture.
@@ -101,31 +97,37 @@ public final class XmppWebSocketTransportModule
         }
     }
 
-    final class EstablishingWebSocketConnectionState extends State {
+    final class EstablishingWebSocketConnectionState extends State.AbstractTransport {
         protected EstablishingWebSocketConnectionState(StateDescriptor stateDescriptor,
                         ModularXmppClientToServerConnectionInternal connectionInternal) {
-            super(stateDescriptor, connectionInternal);
+            super(websocketTransport, stateDescriptor, connectionInternal);
         }
 
         @Override
-        public AttemptResult transitionInto(WalkStateGraphContext walkStateGraphContext)
+        public AttemptResult transitionInto(WalkStateGraphContext walkStateGraphContext) throws InterruptedException,
-                        throws IOException, SmackException, InterruptedException, XMPPException {
+                        NoResponseException, NotConnectedException, SmackException, XMPPException {
             WebSocketConnectionAttemptState connectionAttemptState = new WebSocketConnectionAttemptState(
                             connectionInternal, discoveredWebSocketEndpoints, this);
 
-            try {
+            StateTransitionResult.Failure failure = connectionAttemptState.establishWebSocketConnection();
-                websocket = connectionAttemptState.establishWebSocketConnection();
+            if (failure != null) {
-            } catch (InterruptedException | WebSocketException e) {
-                StateTransitionResult.Failure failure = new StateTransitionResult.FailureCausedByException<Exception>(e);
                 return failure;
             }
 
+            websocket = connectionAttemptState.getConnectedWebSocket();
+
             connectionInternal.setTransport(websocketTransport);
 
-            WebSocketRemoteConnectionEndpoint connectedEndpoint = connectionAttemptState.getConnectedEndpoint();
+            // TODO: It appears this should be done in a generic way. I'd assume we always
+            // have to wait for stream features after the connection was established. But I
+            // am not yet 100% positive that this is the case for every transport. Hence keep it here for now(?).
+            // See also similar comment in XmppTcpTransportModule.
+            // Maybe move this into ConnectedButUnauthenticated state's transitionInto() method? That seems to be the
+            // right place.
+            connectionInternal.newStreamOpenWaitForFeaturesSequence("stream features after initial connection");
 
             // Construct a WebSocketConnectedResult using the connected endpoint.
-            return new WebSocketConnectedResult(connectedEndpoint);
+            return new WebSocketConnectedResult(websocket.getEndpoint());
         }
     }
 
@@ -140,7 +142,7 @@ public final class XmppWebSocketTransportModule
         final WebSocketRemoteConnectionEndpoint connectedEndpoint;
 
         public WebSocketConnectedResult(WebSocketRemoteConnectionEndpoint connectedEndpoint) {
-            super("WebSocket connection establised with endpoint: " + connectedEndpoint.getWebSocketEndpoint());
+            super("WebSocket connection establised with endpoint: " + connectedEndpoint);
             this.connectedEndpoint = connectedEndpoint;
         }
     }
@@ -164,6 +166,12 @@ public final class XmppWebSocketTransportModule
             discoveredWebSocketEndpoints = null;
         }
 
+        @Override
+        public boolean hasUseableConnectionEndpoints() {
+            return discoveredWebSocketEndpoints != null;
+        }
+
+        @SuppressWarnings("incomplete-switch")
         @Override
         protected List<SmackFuture<LookupConnectionEndpointsResult, Exception>> lookupConnectionEndpoints() {
             // Assert that there are no stale discovered endpoints prior performing the lookup.
@@ -172,51 +180,56 @@ public final class XmppWebSocketTransportModule
             InternalSmackFuture<LookupConnectionEndpointsResult, Exception> websocketEndpointsLookupFuture = new InternalSmackFuture<>();
 
             connectionInternal.asyncGo(() -> {
+                Result result = null;
 
-                WebSocketRemoteConnectionEndpoint providedEndpoint = null;
-
-                // Check if there is a websocket endpoint already configured.
-                URI uri = moduleDescriptor.getExplicitlyProvidedUri();
-                if (uri != null) {
-                    providedEndpoint = new WebSocketRemoteConnectionEndpoint(uri);
-                }
-
-                if (!moduleDescriptor.isWebSocketEndpointDiscoveryEnabled()) {
-                    // If discovery is disabled, assert that the provided endpoint isn't null.
-                    assert providedEndpoint != null;
-
-                    SecurityMode mode = connectionInternal.connection.getConfiguration().getSecurityMode();
-                    if ((providedEndpoint.isSecureEndpoint() &&
-                            mode.equals(SecurityMode.disabled))
-                            || (!providedEndpoint.isSecureEndpoint() &&
-                                    mode.equals(SecurityMode.required))) {
-                        throw new IllegalStateException("Explicitly configured uri: " + providedEndpoint.getWebSocketEndpoint().toString()
-                                + " does not comply with the configured security mode: " + mode);
-                    }
-
-                    // Generate Result for explicitly configured endpoint.
-                    Result manualResult = new Result(Arrays.asList(providedEndpoint), null);
-
-                    LookupConnectionEndpointsResult endpointsResult = new DiscoveredWebSocketEndpoints(manualResult);
-
-                    websocketEndpointsLookupFuture.setResult(endpointsResult);
-                } else {
-                    DomainBareJid host = connectionInternal.connection.getXMPPServiceDomain();
                 ModularXmppClientToServerConnectionConfiguration configuration = connectionInternal.connection.getConfiguration();
-                    SecurityMode mode = configuration.getSecurityMode();
+                DomainBareJid host = configuration.getXMPPServiceDomain();
 
+                if (moduleDescriptor.isWebSocketEndpointDiscoveryEnabled()) {
                     // Fetch remote endpoints.
-                    Result xep0156result = WebSocketRemoteConnectionEndpointLookup.lookup(host, mode);
+                    result = WebSocketRemoteConnectionEndpointLookup.lookup(host);
+                }
 
-                    List<WebSocketRemoteConnectionEndpoint> discoveredEndpoints = xep0156result.discoveredRemoteConnectionEndpoints;
+                WebSocketRemoteConnectionEndpoint providedEndpoint = moduleDescriptor.getExplicitlyProvidedEndpoint();
+                if (providedEndpoint != null) {
+                    // If there was not automatic lookup that produced a result, then create a result now.
+                    if (result == null) {
+                        result = new Result();
+                    }
 
-                    // Generate result considering both manual and fetched endpoints.
+                    // We insert the provided endpoint at the beginning of the list, so that it is used first.
-                    Result finalResult = new Result(discoveredEndpoints, xep0156result.getLookupFailures());
+                    final int INSERT_INDEX = 0;
+                    if (providedEndpoint instanceof SecureWebSocketRemoteConnectionEndpoint) {
+                        SecureWebSocketRemoteConnectionEndpoint secureEndpoint = (SecureWebSocketRemoteConnectionEndpoint) providedEndpoint;
+                        result.discoveredSecureEndpoints.add(INSERT_INDEX, secureEndpoint);
+                    } else if (providedEndpoint instanceof InsecureWebSocketRemoteConnectionEndpoint) {
+                        InsecureWebSocketRemoteConnectionEndpoint insecureEndpoint = (InsecureWebSocketRemoteConnectionEndpoint) providedEndpoint;
+                        result.discoveredInsecureEndpoints.add(INSERT_INDEX, insecureEndpoint);
+                    } else {
+                        throw new AssertionError();
+                    }
+                }
 
-                    LookupConnectionEndpointsResult endpointsResult = new DiscoveredWebSocketEndpoints(finalResult);
+                if (moduleDescriptor.isImplicitWebSocketEndpointEnabled()) {
+                    String urlWithoutScheme = "://" + host + ":5443/ws";
+
+                    SecureWebSocketRemoteConnectionEndpoint implicitSecureEndpoint = SecureWebSocketRemoteConnectionEndpoint.from(
+                                    WebSocketRemoteConnectionEndpoint.SECURE_WEB_SOCKET_SCHEME + urlWithoutScheme);
+                    result.discoveredSecureEndpoints.add(implicitSecureEndpoint);
+
+                    InsecureWebSocketRemoteConnectionEndpoint implicitInsecureEndpoint = InsecureWebSocketRemoteConnectionEndpoint.from(
+                                    WebSocketRemoteConnectionEndpoint.INSECURE_WEB_SOCKET_SCHEME + urlWithoutScheme);
+                    result.discoveredInsecureEndpoints.add(implicitInsecureEndpoint);
+                }
+
+                final LookupConnectionEndpointsResult endpointsResult;
+                if (result.isEmpty()) {
+                    endpointsResult = new WebSocketEndpointsDiscoveryFailed(result.lookupFailures);
+                } else {
+                    endpointsResult = new DiscoveredWebSocketEndpoints(result);
+                }
 
                 websocketEndpointsLookupFuture.setResult(endpointsResult);
-                }
             });
 
             return Collections.singletonList(websocketEndpointsLookupFuture);
@@ -238,11 +251,11 @@ public final class XmppWebSocketTransportModule
 
         @Override
         protected void notifyAboutNewOutgoingElements() {
-            Queue<TopLevelStreamElement> outgoingElementsQueue = connectionInternal.outgoingElementsQueue;
+            final Queue<TopLevelStreamElement> outgoingElementsQueue = connectionInternal.outgoingElementsQueue;
             asyncButOrderedOutgoingElementsQueue.performAsyncButOrdered(outgoingElementsQueue, () -> {
-                // Once new outgoingElement is notified, send the top level stream element obtained by polling.
+                for (TopLevelStreamElement topLevelStreamElement; (topLevelStreamElement = outgoingElementsQueue.poll()) != null;) {
-                TopLevelStreamElement topLevelStreamElement = outgoingElementsQueue.poll();
                     websocket.send(topLevelStreamElement);
+                }
             });
         }
 
@@ -268,15 +281,11 @@ public final class XmppWebSocketTransportModule
 
         @Override
         public StreamOpenAndCloseFactory getStreamOpenAndCloseFactory() {
+            // TODO: Create extra class for this?
             return new StreamOpenAndCloseFactory() {
                 @Override
-                public AbstractStreamOpen createStreamOpen(CharSequence to, CharSequence from, String id, String lang) {
+                public AbstractStreamOpen createStreamOpen(DomainBareJid to, CharSequence from, String id, String lang) {
-                    try {
+                    return new WebSocketOpenElement(to);
-                        return new WebSocketOpenElement(JidCreate.domainBareFrom(to));
-                    } catch (XmppStringprepException e) {
-                        Logger.getAnonymousLogger().log(Level.WARNING, "Couldn't create OpenElement", e);
-                        return null;
-                    }
                 }
                 @Override
                 public AbstractStreamClose createStreamClose() {
@@ -295,10 +304,6 @@ public final class XmppWebSocketTransportModule
                 assert result != null;
                 this.result = result;
             }
-
-            public WebSocketRemoteConnectionEndpointLookup.Result getResult() {
-                return result;
-            }
         }
 
         /**
@@ -308,10 +313,13 @@ public final class XmppWebSocketTransportModule
         final class WebSocketEndpointsDiscoveryFailed implements LookupConnectionEndpointsFailed {
             final List<RemoteConnectionEndpointLookupFailure> lookupFailures;
 
-            WebSocketEndpointsDiscoveryFailed(
+            WebSocketEndpointsDiscoveryFailed(RemoteConnectionEndpointLookupFailure lookupFailure) {
-                            WebSocketRemoteConnectionEndpointLookup.Result result) {
+                this(Collections.singletonList(lookupFailure));
-                assert result != null;
+            }
-                lookupFailures = Collections.unmodifiableList(result.lookupFailures);
+
+            WebSocketEndpointsDiscoveryFailed(List<RemoteConnectionEndpointLookupFailure> lookupFailures) {
+                assert lookupFailures != null;
+                this.lookupFailures = Collections.unmodifiableList(lookupFailures);
             }
 
             @Override

smack-websocket/src/main/java/org/jivesoftware/smack/websocket/XmppWebSocketTransportModuleDescriptor.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2020 Aditya Borikar
+ * Copyright 2020 Aditya Borikar, 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 +21,7 @@ import java.net.URISyntaxException;
 import java.util.HashSet;
 import java.util.Set;
 
+import org.jivesoftware.smack.ConnectionConfiguration.SecurityMode;
 import org.jivesoftware.smack.c2s.ModularXmppClientToServerConnection;
 import org.jivesoftware.smack.c2s.ModularXmppClientToServerConnectionConfiguration;
 import org.jivesoftware.smack.c2s.ModularXmppClientToServerConnectionModule;
@@ -29,6 +30,7 @@ import org.jivesoftware.smack.c2s.internal.ModularXmppClientToServerConnectionIn
 import org.jivesoftware.smack.fsm.StateDescriptor;
 import org.jivesoftware.smack.util.Objects;
 import org.jivesoftware.smack.websocket.XmppWebSocketTransportModule.EstablishingWebSocketConnectionStateDescriptor;
+import org.jivesoftware.smack.websocket.rce.WebSocketRemoteConnectionEndpoint;
 
 /**
  * The descriptor class for {@link XmppWebSocketTransportModule}.
@@ -37,12 +39,43 @@ import org.jivesoftware.smack.websocket.XmppWebSocketTransportModule.Establishin
  * use {@link ModularXmppClientToServerConnectionConfiguration.Builder#addModule(ModularXmppClientToServerConnectionModuleDescriptor)}.
  */
 public final class XmppWebSocketTransportModuleDescriptor extends ModularXmppClientToServerConnectionModuleDescriptor {
-    private boolean performWebSocketEndpointDiscovery;
+    private final boolean performWebSocketEndpointDiscovery;
-    private URI uri;
+    private final boolean implicitWebSocketEndpoint;
+    private final URI uri;
+    private final WebSocketRemoteConnectionEndpoint wsRce;
 
     public XmppWebSocketTransportModuleDescriptor(Builder builder) {
         this.performWebSocketEndpointDiscovery = builder.performWebSocketEndpointDiscovery;
+        this.implicitWebSocketEndpoint = builder.implicitWebSocketEndpoint;
+
         this.uri = builder.uri;
+        if (uri != null) {
+            wsRce = WebSocketRemoteConnectionEndpoint.from(uri);
+        } else {
+            wsRce = null;
+        }
+    }
+
+    @Override
+    @SuppressWarnings({"incomplete-switch", "MissingCasesInEnumSwitch"})
+    protected void validateConfiguration(ModularXmppClientToServerConnectionConfiguration configuration) {
+        if (wsRce == null) {
+            return;
+        }
+
+        SecurityMode securityMode = configuration.getSecurityMode();
+        switch (securityMode) {
+        case required:
+            if (!wsRce.isSecureEndpoint()) {
+                throw new IllegalArgumentException("The provided WebSocket endpoint " + wsRce + " is not a secure endpoint, but the connection configuration requires secure endpoints");
+            }
+            break;
+        case disabled:
+            if (wsRce.isSecureEndpoint()) {
+                throw new IllegalArgumentException("The provided WebSocket endpoint " + wsRce + " is a secure endpoint, but the connection configuration has security disabled");
+            }
+            break;
+        }
     }
 
     /**
@@ -53,6 +86,10 @@ public final class XmppWebSocketTransportModuleDescriptor extends ModularXmppCli
         return performWebSocketEndpointDiscovery;
     }
 
+    public boolean isImplicitWebSocketEndpointEnabled() {
+        return implicitWebSocketEndpoint;
+    }
+
     /**
      * Returns explicitly configured websocket endpoint uri.
      * @return uri
@@ -61,6 +98,10 @@ public final class XmppWebSocketTransportModuleDescriptor extends ModularXmppCli
         return uri;
     }
 
+    WebSocketRemoteConnectionEndpoint getExplicitlyProvidedEndpoint() {
+        return wsRce;
+    }
+
     @Override
     protected Set<Class<? extends StateDescriptor>> getStateDescriptors() {
         Set<Class<? extends StateDescriptor>> res = new HashSet<>();
@@ -99,6 +140,7 @@ public final class XmppWebSocketTransportModuleDescriptor extends ModularXmppCli
      */
     public static final class Builder extends ModularXmppClientToServerConnectionModuleDescriptor.Builder {
         private boolean performWebSocketEndpointDiscovery = true;
+        private boolean implicitWebSocketEndpoint = true;
         private URI uri;
 
         private Builder(
@@ -119,15 +161,20 @@ public final class XmppWebSocketTransportModuleDescriptor extends ModularXmppCli
 
         public Builder explicitlySetWebSocketEndpoint(CharSequence endpoint) throws URISyntaxException {
             URI endpointUri = new URI(endpoint.toString());
-            return explicitlySetWebSocketEndpointAndDiscovery(endpointUri, true);
+            return explicitlySetWebSocketEndpoint(endpointUri);
         }
 
-        public Builder explicitlySetWebSocketEndpoint(CharSequence endpoint, boolean performWebSocketEndpointDiscovery)
+        public Builder explicitlySetWebSocketEndpointAndDiscovery(CharSequence endpoint, boolean performWebSocketEndpointDiscovery)
                 throws URISyntaxException {
             URI endpointUri = new URI(endpoint.toString());
             return explicitlySetWebSocketEndpointAndDiscovery(endpointUri, performWebSocketEndpointDiscovery);
         }
 
+        public Builder disableImplicitWebsocketEndpoint() {
+            implicitWebSocketEndpoint = false;
+            return this;
+        }
+
         @Override
         public ModularXmppClientToServerConnectionModuleDescriptor build() {
             return new XmppWebSocketTransportModuleDescriptor(this);

smack-websocket/src/main/java/org/jivesoftware/smack/websocket/impl/AbstractWebSocket.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2020 Aditya Borikar.
+ * Copyright 2020 Aditya Borikar, 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.
@@ -18,40 +18,92 @@ package org.jivesoftware.smack.websocket.impl;
 
 import javax.net.ssl.SSLSession;
 
+import org.jivesoftware.smack.SmackFuture;
+import org.jivesoftware.smack.c2s.internal.ModularXmppClientToServerConnectionInternal;
 import org.jivesoftware.smack.packet.TopLevelStreamElement;
+import org.jivesoftware.smack.packet.XmlEnvironment;
 import org.jivesoftware.smack.websocket.rce.WebSocketRemoteConnectionEndpoint;
 
 public abstract class AbstractWebSocket {
 
-    protected enum WebSocketConnectionPhase {
+    protected final ModularXmppClientToServerConnectionInternal connectionInternal;
-        openFrameSent,
+
-        exchangingTopLevelStreamElements
+    protected final WebSocketRemoteConnectionEndpoint endpoint;
+
+    protected AbstractWebSocket(WebSocketRemoteConnectionEndpoint endpoint,
+                    ModularXmppClientToServerConnectionInternal connectionInternal) {
+        this.endpoint = endpoint;
+        this.connectionInternal = connectionInternal;
     }
 
-    protected static String getStreamFromOpenElement(String openElement) {
+    public final WebSocketRemoteConnectionEndpoint getEndpoint() {
+        return endpoint;
+    }
+
+    private String streamOpen;
+    private String streamClose;
+
+    protected final void onIncomingWebSocketElement(String element) {
+        // TODO: Once smack-websocket-java15 is there, we have to re-evaluate if the async operation here is still
+        // required, or if it should only be performed if OkHTTP is used.
+        if (isOpenElement(element)) {
+            // Transform the XMPP WebSocket <open/> element to a RFC 6120 <stream> open tag.
+            streamOpen = getStreamFromOpenElement(element);
+            streamClose = connectionInternal.onStreamOpen(streamOpen);
+            return;
+        }
+
+        if (isCloseElement(element)) {
+            connectionInternal.onStreamClosed();
+            return;
+        }
+
+        connectionInternal.withSmackDebugger(debugger -> debugger.onIncomingElementCompleted());
+
+        // TODO: Do we need to wrap the element again in the stream open to get the
+        // correct XML scoping (just like the modular TCP connection does)? It appears
+        // that this not really required, as onStreamOpen() will set the incomingStreamEnvironment, which is used for
+        // parsing.
+        String wrappedCompleteElement = streamOpen + element + streamClose;
+        connectionInternal.parseAndProcessElement(wrappedCompleteElement);
+    }
+
+    static String getStreamFromOpenElement(String openElement) {
         String streamElement = openElement.replaceFirst("\\A<open ", "<stream ")
                                           .replace("urn:ietf:params:xml:ns:xmpp-framing", "jabber:client")
                                           .replaceFirst("/>\\s*\\z", ">");
         return streamElement;
     }
 
-    protected static boolean isOpenElement(String text) {
+    // TODO: Make this method less fragile, e.g. by parsing a little bit into the element to ensure that this is an
+    // <open/> element qualified by the correct namespace.
+    static boolean isOpenElement(String text) {
         if (text.startsWith("<open ")) {
             return true;
         }
         return false;
     }
 
-    protected static boolean isCloseElement(String text) {
+    // TODO: Make this method less fragile, e.g. by parsing a little bit into the element to ensure that this is an
+    // <close/> element qualified by the correct namespace. The fragility comes due the fact that the element could,
+    // inter alia, be specified as
+    // <close:close xmlns:close="urn:ietf:params:xml:ns:xmpp-framing"/>
+    static boolean isCloseElement(String text) {
         if (text.startsWith("<close xmlns='urn:ietf:params:xml:ns:xmpp-framing'/>")) {
             return true;
         }
         return false;
     }
 
-    public abstract void connect(WebSocketRemoteConnectionEndpoint endpoint) throws Throwable;
+    public abstract SmackFuture<AbstractWebSocket, Exception> getFuture();
 
-    public abstract void send(TopLevelStreamElement element);
+    public final void send(TopLevelStreamElement element) {
+        XmlEnvironment outgoingStreamXmlEnvironment = connectionInternal.getOutgoingStreamXmlEnvironment();
+        String elementString = element.toXML(outgoingStreamXmlEnvironment).toString();
+        send(elementString);
+    }
+
+    protected abstract void send(String element);
 
     public abstract void disconnect(int code, String message);
 

smack-websocket/src/main/java/org/jivesoftware/smack/websocket/impl/WebSocketFactory.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.
@@ -17,9 +17,11 @@
 package org.jivesoftware.smack.websocket.impl;
 
 import org.jivesoftware.smack.c2s.internal.ModularXmppClientToServerConnectionInternal;
+import org.jivesoftware.smack.websocket.rce.WebSocketRemoteConnectionEndpoint;
 
 public interface WebSocketFactory {
 
-    AbstractWebSocket create(ModularXmppClientToServerConnectionInternal connectionInternal);
+    AbstractWebSocket create(WebSocketRemoteConnectionEndpoint endpoint,
+                    ModularXmppClientToServerConnectionInternal connectionInternal);
 
 }

smack-websocket/src/main/java/org/jivesoftware/smack/websocket/impl/WebSocketFactoryService.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.
@@ -20,12 +20,14 @@ import java.util.Iterator;
 import java.util.ServiceLoader;
 
 import org.jivesoftware.smack.c2s.internal.ModularXmppClientToServerConnectionInternal;
+import org.jivesoftware.smack.websocket.rce.WebSocketRemoteConnectionEndpoint;
 
 public final class WebSocketFactoryService {
 
     private static final ServiceLoader<WebSocketFactory> SERVICE_LOADER = ServiceLoader.load(WebSocketFactory.class);
 
-    public static AbstractWebSocket createWebSocket(ModularXmppClientToServerConnectionInternal connectionInternal) {
+    public static AbstractWebSocket createWebSocket(WebSocketRemoteConnectionEndpoint endpoint,
+                    ModularXmppClientToServerConnectionInternal connectionInternal) {
         assert connectionInternal != null;
 
         Iterator<WebSocketFactory> websocketFactories = SERVICE_LOADER.iterator();
@@ -34,7 +36,7 @@ public final class WebSocketFactoryService {
         }
 
         WebSocketFactory websocketFactory = websocketFactories.next();
-        return websocketFactory.create(connectionInternal);
+        return websocketFactory.create(endpoint, connectionInternal);
     }
 
 }

smack-websocket/src/main/java/org/jivesoftware/smack/websocket/rce/InsecureWebSocketRemoteConnectionEndpoint.java

@@ -0,0 +1,39 @@
+/**
+ *
+ * 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.
+ * 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.websocket.rce;
+
+import java.net.URI;
+
+public class InsecureWebSocketRemoteConnectionEndpoint extends WebSocketRemoteConnectionEndpoint {
+
+    protected InsecureWebSocketRemoteConnectionEndpoint(URI uri) {
+        super(uri);
+    }
+
+    @Override
+    public final boolean isSecureEndpoint() {
+        return false;
+    }
+
+    public static final InsecureWebSocketRemoteConnectionEndpoint from(CharSequence cs) {
+        URI uri = URI.create(cs.toString());
+        if (!uri.getScheme().equals(INSECURE_WEB_SOCKET_SCHEME)) {
+            throw new IllegalArgumentException(uri + " is not a insecure WebSocket");
+        }
+        return new InsecureWebSocketRemoteConnectionEndpoint(uri);
+    }
+}

smack-websocket/src/main/java/org/jivesoftware/smack/websocket/rce/SecureWebSocketRemoteConnectionEndpoint.java

@@ -0,0 +1,39 @@
+/**
+ *
+ * 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.
+ * 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.websocket.rce;
+
+import java.net.URI;
+
+public class SecureWebSocketRemoteConnectionEndpoint extends WebSocketRemoteConnectionEndpoint {
+
+    protected SecureWebSocketRemoteConnectionEndpoint(URI uri) {
+        super(uri);
+    }
+
+    @Override
+    public final boolean isSecureEndpoint() {
+        return true;
+    }
+
+    public static final SecureWebSocketRemoteConnectionEndpoint from(CharSequence cs) {
+        URI uri = URI.create(cs.toString());
+        if (!uri.getScheme().equals(SECURE_WEB_SOCKET_SCHEME)) {
+            throw new IllegalArgumentException(uri + " is not a secure WebSocket");
+        }
+        return new SecureWebSocketRemoteConnectionEndpoint(uri);
+    }
+}

smack-websocket/src/main/java/org/jivesoftware/smack/websocket/rce/WebSocketRemoteConnectionEndpoint.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2020 Aditya Borikar
+ * Copyright 2020-2021 Aditya Borikar, Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,66 +20,100 @@ import java.net.InetAddress;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.net.UnknownHostException;
+import java.util.Arrays;
 import java.util.Collection;
-import java.util.Collections;
+import java.util.List;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
 import org.jivesoftware.smack.datatypes.UInt16;
 import org.jivesoftware.smack.util.rce.RemoteConnectionEndpoint;
 
-public final class WebSocketRemoteConnectionEndpoint implements RemoteConnectionEndpoint {
+public abstract class WebSocketRemoteConnectionEndpoint implements RemoteConnectionEndpoint {
+
+    public static final String INSECURE_WEB_SOCKET_SCHEME = "ws";
+    public static final String SECURE_WEB_SOCKET_SCHEME = INSECURE_WEB_SOCKET_SCHEME + "s";
 
     private static final Logger LOGGER = Logger.getAnonymousLogger();
 
     private final URI uri;
+    private final UInt16 port;
 
-    public WebSocketRemoteConnectionEndpoint(String uri) throws URISyntaxException {
+    protected WebSocketRemoteConnectionEndpoint(URI uri) {
-        this(new URI(uri));
-    }
-
-    public WebSocketRemoteConnectionEndpoint(URI uri) {
         this.uri = uri;
-        String scheme = uri.getScheme();
+        int portInt = uri.getPort();
-        if (!(scheme.equals("ws") || scheme.equals("wss"))) {
+        if (portInt >= 0) {
-            throw new IllegalArgumentException("Only allowed protocols are ws and wss");
+            port = UInt16.from(portInt);
+        } else {
+            port = null;
         }
     }
 
-    public URI getWebSocketEndpoint() {
+    public final URI getUri() {
         return uri;
     }
 
-    public boolean isSecureEndpoint() {
-        if (uri.getScheme().equals("wss")) {
-            return true;
-        }
-        return false;
-    }
-
     @Override
-    public CharSequence getHost() {
+    public final String getHost() {
         return uri.getHost();
     }
 
     @Override
     public UInt16 getPort() {
-        return UInt16.from(uri.getPort());
+        return port;
+    }
+
+    public abstract boolean isSecureEndpoint();
+
+    private List<? extends InetAddress> inetAddresses;
+
+    private void resolveInetAddressesIfRequired() {
+        if (inetAddresses != null) {
+            return;
+        }
+
+        String host = getHost();
+        InetAddress[] addresses;
+        try {
+            addresses = InetAddress.getAllByName(host);
+        } catch (UnknownHostException e) {
+            LOGGER.log(Level.WARNING, "Could not resolve IP addresses of " + host, e);
+            return;
+        }
+        inetAddresses = Arrays.asList(addresses);
     }
 
     @Override
     public Collection<? extends InetAddress> getInetAddresses() {
-        try {
+        resolveInetAddressesIfRequired();
-            InetAddress address = InetAddress.getByName(getHost().toString());
+        return inetAddresses;
-            return Collections.singletonList(address);
-        } catch (UnknownHostException e) {
-            LOGGER.log(Level.INFO, "Unknown Host Exception ", e);
-        }
-        return null;
     }
 
     @Override
     public String getDescription() {
         return null;
     }
+
+    @Override
+    public String toString() {
+        return uri.toString();
+    }
+
+    public static WebSocketRemoteConnectionEndpoint from(CharSequence uriCharSequence) throws URISyntaxException {
+        String uriString = uriCharSequence.toString();
+        URI uri = URI.create(uriString);
+        return from(uri);
+    }
+
+    public static WebSocketRemoteConnectionEndpoint from(URI uri) {
+        String scheme = uri.getScheme();
+        switch (scheme) {
+        case INSECURE_WEB_SOCKET_SCHEME:
+            return new InsecureWebSocketRemoteConnectionEndpoint(uri);
+        case SECURE_WEB_SOCKET_SCHEME:
+            return new SecureWebSocketRemoteConnectionEndpoint(uri);
+        default:
+            throw new IllegalArgumentException("Only allowed protocols are " + INSECURE_WEB_SOCKET_SCHEME + " and " + SECURE_WEB_SOCKET_SCHEME);
+        }
+    }
 }

smack-websocket/src/main/java/org/jivesoftware/smack/websocket/rce/WebSocketRemoteConnectionEndpointLookup.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2020 Aditya Borikar
+ * Copyright 2020 Aditya Borikar, Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,10 +20,9 @@ import java.io.IOException;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.util.ArrayList;
-import java.util.Iterator;
+import java.util.Collections;
 import java.util.List;
 
-import org.jivesoftware.smack.ConnectionConfiguration.SecurityMode;
 import org.jivesoftware.smack.altconnections.HttpLookupMethod;
 import org.jivesoftware.smack.altconnections.HttpLookupMethod.LinkRelation;
 import org.jivesoftware.smack.util.rce.RemoteConnectionEndpointLookupFailure;
@@ -33,9 +32,8 @@ import org.jxmpp.jid.DomainBareJid;
 
 public final class WebSocketRemoteConnectionEndpointLookup {
 
-    public static Result lookup(DomainBareJid domainBareJid, SecurityMode securityMode) {
+    public static Result lookup(DomainBareJid domainBareJid) {
         List<RemoteConnectionEndpointLookupFailure> lookupFailures = new ArrayList<>(1);
-        List<WebSocketRemoteConnectionEndpoint> discoveredRemoteConnectionEndpoints = new ArrayList<>();
 
         List<URI> rcUriList = null;
         try {
@@ -45,67 +43,69 @@ public final class WebSocketRemoteConnectionEndpointLookup {
         } catch (IOException | XmlPullParserException | URISyntaxException e) {
             lookupFailures.add(new RemoteConnectionEndpointLookupFailure.HttpLookupFailure(
                             domainBareJid, e));
-            return new Result(discoveredRemoteConnectionEndpoints, lookupFailures);
+            return new Result(lookupFailures);
         }
 
-        if (rcUriList.isEmpty()) {
+        List<SecureWebSocketRemoteConnectionEndpoint> discoveredSecureEndpoints = new ArrayList<>(rcUriList.size());
-            throw new IllegalStateException("No endpoints were found inside host-meta");
+        List<InsecureWebSocketRemoteConnectionEndpoint> discoveredInsecureEndpoints = new ArrayList<>(rcUriList.size());
-        }
 
-        // Convert rcUriList to List<WebSocketRemoteConnectionEndpoint>
+        for (URI webSocketUri : rcUriList) {
-        Iterator<URI> iterator = rcUriList.iterator();
+            WebSocketRemoteConnectionEndpoint wsRce = WebSocketRemoteConnectionEndpoint.from(webSocketUri);
-        List<WebSocketRemoteConnectionEndpoint> rceList = new ArrayList<>();
+            if (wsRce instanceof SecureWebSocketRemoteConnectionEndpoint) {
-        while (iterator.hasNext()) {
+                SecureWebSocketRemoteConnectionEndpoint secureWsRce = (SecureWebSocketRemoteConnectionEndpoint) wsRce;
-            rceList.add(new WebSocketRemoteConnectionEndpoint(iterator.next()));
+                discoveredSecureEndpoints.add(secureWsRce);
-        }
+            } else if (wsRce instanceof InsecureWebSocketRemoteConnectionEndpoint) {
-
+                InsecureWebSocketRemoteConnectionEndpoint insecureWsRce = (InsecureWebSocketRemoteConnectionEndpoint) wsRce;
-        switch (securityMode) {
+                discoveredInsecureEndpoints.add(insecureWsRce);
-            case ifpossible:
-                // If security mode equals `if-possible`, give priority to secure endpoints over insecure endpoints.
-
-                // Seprate secure and unsecure endpoints.
-                List<WebSocketRemoteConnectionEndpoint> secureEndpointsForSecurityModeIfPossible = new ArrayList<>();
-                List<WebSocketRemoteConnectionEndpoint> insecureEndpointsForSecurityModeIfPossible = new ArrayList<>();
-                for (WebSocketRemoteConnectionEndpoint uri : rceList) {
-                    if (uri.isSecureEndpoint()) {
-                        secureEndpointsForSecurityModeIfPossible.add(uri);
             } else {
-                        insecureEndpointsForSecurityModeIfPossible.add(uri);
+                // WebSocketRemoteConnectionEndpoint.from() must return an instance which type is one of the above.
+                throw new AssertionError();
             }
         }
-                discoveredRemoteConnectionEndpoints = secureEndpointsForSecurityModeIfPossible;
+
-                discoveredRemoteConnectionEndpoints.addAll(insecureEndpointsForSecurityModeIfPossible);
+        return new Result(discoveredSecureEndpoints, discoveredInsecureEndpoints, lookupFailures);
-                break;
-            case required:
-            case disabled:
-                /**
-                 * If, SecurityMode equals to required, accept wss endpoints (secure endpoints) only or,
-                 * if SecurityMode equals to disabled, accept ws endpoints (unsecure endpoints) only.
-                 */
-                for (WebSocketRemoteConnectionEndpoint uri : rceList) {
-                    if ((securityMode.equals(SecurityMode.disabled) && !uri.isSecureEndpoint())
-                                    || (securityMode.equals(SecurityMode.required) && uri.isSecureEndpoint())) {
-                        discoveredRemoteConnectionEndpoints.add(uri);
-                    }
-                }
-                break;
-            default:
-        }
-        return new Result(discoveredRemoteConnectionEndpoints, lookupFailures);
     }
 
     public static final class Result {
-        public final List<WebSocketRemoteConnectionEndpoint> discoveredRemoteConnectionEndpoints;
+        public final List<SecureWebSocketRemoteConnectionEndpoint> discoveredSecureEndpoints;
+        public final List<InsecureWebSocketRemoteConnectionEndpoint> discoveredInsecureEndpoints;
         public final List<RemoteConnectionEndpointLookupFailure> lookupFailures;
 
-        public Result(List<WebSocketRemoteConnectionEndpoint> discoveredRemoteConnectionEndpoints,
+        public Result() {
+            this(Collections.emptyList());
+        }
+
+        public Result(List<RemoteConnectionEndpointLookupFailure> lookupFailures) {
+            // The list of endpoints needs to be mutable, because maybe a user supplied endpoint will be added to it.
+            // Hence we do not use Collections.emptyList() as argument for the discovered endpoints.
+            this(new ArrayList<>(1), new ArrayList<>(1), lookupFailures);
+        }
+
+        public Result(List<SecureWebSocketRemoteConnectionEndpoint> discoveredSecureEndpoints,
+                        List<InsecureWebSocketRemoteConnectionEndpoint> discoveredInsecureEndpoints,
                         List<RemoteConnectionEndpointLookupFailure> lookupFailures) {
-            this.discoveredRemoteConnectionEndpoints = discoveredRemoteConnectionEndpoints;
+            this.discoveredSecureEndpoints = discoveredSecureEndpoints;
+            this.discoveredInsecureEndpoints = discoveredInsecureEndpoints;
             this.lookupFailures = lookupFailures;
         }
 
-        public List<WebSocketRemoteConnectionEndpoint> getDiscoveredRemoteConnectionEndpoints() {
+        public boolean isEmpty() {
-            return discoveredRemoteConnectionEndpoints;
+            return discoveredSecureEndpoints.isEmpty() && discoveredInsecureEndpoints.isEmpty();
+        }
+
+        public int discoveredEndpointCount() {
+            return discoveredSecureEndpoints.size() + discoveredInsecureEndpoints.size();
+        }
+
+        // TODO: Remove the following methods since the fields are already public? Or make the fields private and use
+        // the methods? I tend to remove the methods, as their method name is pretty long. But OTOH the fields reference
+        // mutable datastructes, which is uncommon to be public.
+        public List<SecureWebSocketRemoteConnectionEndpoint> getDiscoveredSecureRemoteConnectionEndpoints() {
+            return discoveredSecureEndpoints;
+        }
+
+        public List<InsecureWebSocketRemoteConnectionEndpoint> getDiscoveredInsecureRemoteConnectionEndpoints() {
+            return discoveredInsecureEndpoints;
         }
 
         public List<RemoteConnectionEndpointLookupFailure> getLookupFailures() {

smack-websocket/src/test/java/org/jivesoftware/smack/websocket/XmppWebSocketTransportModuleTest.java

@@ -17,24 +17,15 @@
 package org.jivesoftware.smack.websocket;
 
 import static org.junit.jupiter.api.Assertions.assertNotNull;
-import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import static org.mockito.Mockito.mock;
 
 import java.net.URI;
 import java.net.URISyntaxException;
-import java.util.ArrayList;
-import java.util.List;
 
 import org.jivesoftware.smack.c2s.ModularXmppClientToServerConnection;
 import org.jivesoftware.smack.c2s.ModularXmppClientToServerConnectionConfiguration;
 import org.jivesoftware.smack.c2s.internal.ModularXmppClientToServerConnectionInternal;
-import org.jivesoftware.smack.util.rce.RemoteConnectionEndpointLookupFailure;
-import org.jivesoftware.smack.util.rce.RemoteConnectionEndpointLookupFailure.HttpLookupFailure;
-import org.jivesoftware.smack.websocket.XmppWebSocketTransportModule.XmppWebSocketTransport.DiscoveredWebSocketEndpoints;
-import org.jivesoftware.smack.websocket.XmppWebSocketTransportModule.XmppWebSocketTransport.WebSocketEndpointsDiscoveryFailed;
-import org.jivesoftware.smack.websocket.rce.WebSocketRemoteConnectionEndpoint;
-import org.jivesoftware.smack.websocket.rce.WebSocketRemoteConnectionEndpointLookup.Result;
 
 import org.junit.jupiter.api.Test;
 import org.jxmpp.stringprep.XmppStringprepException;
@@ -64,42 +55,6 @@ public class XmppWebSocketTransportModuleTest {
         assertNotNull(websocketTransportModuleDescriptor);
     }
 
-    @Test
-    public void websocketEndpointDiscoveryTest() throws URISyntaxException {
-        XmppWebSocketTransportModuleDescriptor websocketTransportModuleDescriptor = getWebSocketDescriptor();
-        ModularXmppClientToServerConnectionInternal connectionInternal = mock(ModularXmppClientToServerConnectionInternal.class);
-
-        XmppWebSocketTransportModule transportModule
-                        = new XmppWebSocketTransportModule(websocketTransportModuleDescriptor, connectionInternal);
-
-        XmppWebSocketTransportModule.XmppWebSocketTransport transport = transportModule.getTransport();
-
-        assertThrows(AssertionError.class, () -> transport.new DiscoveredWebSocketEndpoints(null));
-        assertThrows(AssertionError.class, () -> transport.new WebSocketEndpointsDiscoveryFailed(null));
-
-        WebSocketRemoteConnectionEndpoint endpoint = new WebSocketRemoteConnectionEndpoint("wss://localhost.org:7443/ws/");
-
-        List<WebSocketRemoteConnectionEndpoint> discoveredRemoteConnectionEndpoints = new ArrayList<>();
-        discoveredRemoteConnectionEndpoints.add(endpoint);
-
-        HttpLookupFailure httpLookupFailure = new RemoteConnectionEndpointLookupFailure.HttpLookupFailure(null, null);
-        List<RemoteConnectionEndpointLookupFailure> failureList = new ArrayList<>();
-        failureList.add(httpLookupFailure);
-        Result result = new Result(discoveredRemoteConnectionEndpoints, failureList);
-
-        DiscoveredWebSocketEndpoints discoveredWebSocketEndpoints = transport.new DiscoveredWebSocketEndpoints(result);
-        assertNotNull(discoveredWebSocketEndpoints.getResult());
-
-        WebSocketEndpointsDiscoveryFailed endpointsDiscoveryFailed = transport.new WebSocketEndpointsDiscoveryFailed(result);
-        assertNotNull(endpointsDiscoveryFailed.toString());
-    }
-
-    @Test
-    public void websocketConnectedResultTest() throws URISyntaxException {
-        WebSocketRemoteConnectionEndpoint connectedEndpoint = new WebSocketRemoteConnectionEndpoint("wss://localhost.org:7443/ws/");
-        assertNotNull(new XmppWebSocketTransportModule.WebSocketConnectedResult(connectedEndpoint));
-    }
-
     @Test
     public void lookupConnectionEndpointsTest() throws URISyntaxException {
         XmppWebSocketTransportModuleDescriptor websocketTransportModuleDescriptor = getWebSocketDescriptor();

smack-websocket/src/test/java/org/jivesoftware/smack/websocket/rce/WebSocketRemoteConnectionEndpointTest.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.
@@ -26,20 +26,22 @@ import org.jivesoftware.smack.datatypes.UInt16;
 import org.junit.jupiter.api.Test;
 
 public class WebSocketRemoteConnectionEndpointTest {
+
     @Test
     public void endpointTest() throws URISyntaxException {
         String endpointString = "ws://fooDomain.org:7070/ws/";
-        WebSocketRemoteConnectionEndpoint endpoint = new WebSocketRemoteConnectionEndpoint(endpointString);
+        WebSocketRemoteConnectionEndpoint endpoint = WebSocketRemoteConnectionEndpoint.from(endpointString);
         assertEquals("fooDomain.org", endpoint.getHost());
         assertEquals(UInt16.from(7070), endpoint.getPort());
-        assertEquals(endpointString, endpoint.getWebSocketEndpoint().toString());
+        assertEquals(endpointString, endpoint.getUri().toString());
     }
 
     @Test
     public void faultyEndpointTest() {
         String faultyProtocolString = "wst://fooDomain.org:7070/ws/";
         assertThrows(IllegalArgumentException.class, () -> {
-            new WebSocketRemoteConnectionEndpoint(faultyProtocolString);
+            WebSocketRemoteConnectionEndpoint.from(faultyProtocolString);
         });
     }
+
 }

smack-websocket/src/testFixtures/java/org/jivesoftware/smack/websocket/test/WebSocketFactoryServiceTestUtil.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.
@@ -20,16 +20,21 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
 
 import static org.mockito.Mockito.mock;
 
+import java.net.URISyntaxException;
+
 import org.jivesoftware.smack.c2s.internal.ModularXmppClientToServerConnectionInternal;
 import org.jivesoftware.smack.websocket.impl.AbstractWebSocket;
 import org.jivesoftware.smack.websocket.impl.WebSocketFactoryService;
+import org.jivesoftware.smack.websocket.rce.WebSocketRemoteConnectionEndpoint;
 
 public class WebSocketFactoryServiceTestUtil {
 
-    public static void createWebSocketTest(Class<? extends AbstractWebSocket> expected) {
+    public static void createWebSocketTest(Class<? extends AbstractWebSocket> expected) throws URISyntaxException {
+        WebSocketRemoteConnectionEndpoint endpoint = WebSocketRemoteConnectionEndpoint.from("wss://example.org");
+
         ModularXmppClientToServerConnectionInternal connectionInternal = mock(ModularXmppClientToServerConnectionInternal.class);
 
-        AbstractWebSocket websocket = WebSocketFactoryService.createWebSocket(connectionInternal);
+        AbstractWebSocket websocket = WebSocketFactoryService.createWebSocket(endpoint, connectionInternal);
         assertEquals(expected, websocket.getClass());
     }