Add StringUtils.requireNotNullOrEmpty and Objects.requireNonNull

and use this in a few places.

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

@@ -75,6 +75,7 @@ import org.jivesoftware.smack.parsing.UnparsablePacket;
 import org.jivesoftware.smack.provider.PacketExtensionProvider;
 import org.jivesoftware.smack.provider.ProviderManager;
 import org.jivesoftware.smack.util.DNSUtil;
+import org.jivesoftware.smack.util.Objects;
 import org.jivesoftware.smack.util.PacketParserUtils;
 import org.jivesoftware.smack.util.ParserUtils;
 import org.jivesoftware.smack.util.SmackExecutorThreadFactory;
@@ -469,8 +470,8 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
      */
     public synchronized void login(CharSequence username, String password, String resource) throws XMPPException,
                     SmackException, IOException {
-        if (!config.allowNullOrEmptyUsername && StringUtils.isNullOrEmpty(username)) {
+        if (!config.allowNullOrEmptyUsername) {
-            throw new IllegalArgumentException("Username must not be null or empty");
+            StringUtils.requireNotNullOrEmpty(username, "Username must not be null or empty");
         }
         throwNotConnectedExceptionIfAppropriate();
         throwAlreadyLoggedInExceptionIfAppropriate();
@@ -618,9 +619,8 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
 
     @Override
     public void sendPacket(Packet packet) throws NotConnectedException {
-        if (packet == null) {
+        Objects.requireNonNull(packet, "Packet must not be null");
-            throw new IllegalArgumentException("Packet must not be null");
+
-        }
         throwNotConnectedExceptionIfAppropriate();
         switch (fromMode) {
         case OMITTED:
@@ -1419,17 +1419,12 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
     public void sendStanzaWithResponseCallback(Packet stanza, PacketFilter replyFilter,
                     final PacketListener callback, final ExceptionCallback exceptionCallback,
                     long timeout) throws NotConnectedException {
-        if (stanza == null) {
+        Objects.requireNonNull(stanza, "stanza must not be null");
-            throw new IllegalArgumentException("stanza must not be null");
-        }
-        if (replyFilter == null) {
         // While Smack allows to add PacketListeners with a PacketFilter value of 'null', we
         // disallow it here in the async API as it makes no sense
-            throw new IllegalArgumentException("replyFilter must not be null");
+        Objects.requireNonNull(replyFilter, "replyFilter must not be null");
-        }
+        Objects.requireNonNull(callback, "callback must not be null");
-        if (callback == null) {
+
-            throw new IllegalArgumentException("callback must not be null");
-        }
         final PacketListener packetListener = new PacketListener() {
             @Override
             public void processPacket(Packet packet) throws NotConnectedException {

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

@@ -18,14 +18,15 @@ package org.jivesoftware.smack;
 
 import java.lang.ref.WeakReference;
 
+import org.jivesoftware.smack.util.Objects;
+
 public abstract class Manager {
 
     final WeakReference<XMPPConnection> weakConnection;
 
     public Manager(XMPPConnection connection) {
-        if (connection == null) {
+        Objects.requireNonNull(connection, "XMPPConnection must not be null");
-            throw new IllegalArgumentException("XMPPConnection must not be null");
+
-        }
         weakConnection = new WeakReference<XMPPConnection>(connection);
     }
 

smack-core/src/main/java/org/jivesoftware/smack/filter/AndFilter.java

@@ -22,6 +22,7 @@ import java.util.Arrays;
 import java.util.List;
 
 import org.jivesoftware.smack.packet.Packet;
+import org.jivesoftware.smack.util.Objects;
 
 /**
  * Implements the logical AND operation over two or more packet filters.
@@ -50,13 +51,9 @@ public class AndFilter implements PacketFilter {
      * @param filters the filters to add.
      */
     public AndFilter(PacketFilter... filters) {
-        if (filters == null) {
+        Objects.requireNonNull(filters, "Parameter must not be null.");
-            throw new IllegalArgumentException("Parameter must not be null.");
-        }
         for(PacketFilter filter : filters) {
-            if(filter == null) {
+            Objects.requireNonNull(filter, "Parameter must not be null.");
-                throw new IllegalArgumentException("Parameter must not be null.");
-            }
         }
         this.filters = new ArrayList<PacketFilter>(Arrays.asList(filters));
     }
@@ -68,9 +65,7 @@ public class AndFilter implements PacketFilter {
      * @param filter a filter to add to the filter list.
      */
     public void addFilter(PacketFilter filter) {
-        if (filter == null) {
+        Objects.requireNonNull(filter, "Parameter must not be null.");
-            throw new IllegalArgumentException("Parameter must not be null.");
-        }
         filters.add(filter);
     }
 

smack-core/src/main/java/org/jivesoftware/smack/filter/OrFilter.java

@@ -22,6 +22,7 @@ import java.util.Arrays;
 import java.util.List;
 
 import org.jivesoftware.smack.packet.Packet;
+import org.jivesoftware.smack.util.Objects;
 
 /**
  * Implements the logical OR operation over two or more packet filters. In
@@ -50,13 +51,9 @@ public class OrFilter implements PacketFilter {
      * @param filters the filters to add.
      */
     public OrFilter(PacketFilter... filters) {
-        if (filters == null) {
+        Objects.requireNonNull(filters, "Parameter must not be null.");
-            throw new IllegalArgumentException("Parameter must not be null.");
-        }
         for(PacketFilter filter : filters) {
-            if(filter == null) {
+            Objects.requireNonNull(filter, "Parameter must not be null.");
-                throw new IllegalArgumentException("Parameter must not be null.");
-            }
         }
         this.filters = new ArrayList<PacketFilter>(Arrays.asList(filters));
     }
@@ -68,9 +65,7 @@ public class OrFilter implements PacketFilter {
      * @param filter a filter to add to the filter list.
      */
     public void addFilter(PacketFilter filter) {
-        if (filter == null) {
+        Objects.requireNonNull(filter, "Parameter must not be null.");
-            throw new IllegalArgumentException("Parameter must not be null.");
-        }
         filters.add(filter);
     }
 

smack-core/src/main/java/org/jivesoftware/smack/filter/PacketExtensionFilter.java

@@ -40,9 +40,8 @@ public class PacketExtensionFilter implements PacketFilter {
      * @param namespace the XML namespace of the packet extension.
      */
     public PacketExtensionFilter(String elementName, String namespace) {
-        if (StringUtils.isNullOrEmpty(namespace)) {
+        StringUtils.requireNotNullOrEmpty(namespace, "namespace must not be null or empty");
-            throw new IllegalArgumentException("namespace must not be null or empty");
+
-        }
         this.elementName = elementName;
         this.namespace = namespace;
     }

smack-core/src/main/java/org/jivesoftware/smack/filter/PacketIDFilter.java

@@ -44,9 +44,7 @@ public class PacketIDFilter implements PacketFilter {
      * @param packetID the packet ID to filter for.
      */
     public PacketIDFilter(String packetID) {
-        if (StringUtils.isNullOrEmpty(packetID)) {
+        StringUtils.requireNotNullOrEmpty(packetID, "Packet ID must not be null or empty.");
-            throw new IllegalArgumentException("Packet ID must not be null or empty.");
-        }
         this.packetID = packetID;
     }
 

smack-core/src/main/java/org/jivesoftware/smack/filter/ThreadFilter.java

@@ -36,9 +36,7 @@ public class ThreadFilter implements PacketFilter {
      * @param thread the thread value to filter for.
      */
     public ThreadFilter(String thread) {
-        if (StringUtils.isNullOrEmpty(thread)) {
+        StringUtils.requireNotNullOrEmpty(thread, "Thread must not be null or empty.");
-            throw new IllegalArgumentException("Thread must not be null or empty.");
-        }
         this.thread = thread;
     }
 

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

@@ -16,6 +16,8 @@
  */
 package org.jivesoftware.smack.packet;
 
+import org.jivesoftware.smack.util.Objects;
+
 public class ErrorIQ extends SimpleIQ {
 
     public static final String ELEMENT = XMPPError.ERROR;
@@ -29,9 +31,7 @@ public class ErrorIQ extends SimpleIQ {
      */
     public ErrorIQ(XMPPError xmppError) {
         super(ELEMENT, null);
-        if (xmppError == null) {
+        Objects.requireNonNull(xmppError, "XMPPError must not be null");
-            throw new IllegalArgumentException("XMPPError must not be null");
-        }
         setType(IQ.Type.error);
         setError(xmppError);
     }

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

@@ -19,6 +19,7 @@ package org.jivesoftware.smack.packet;
 
 import java.util.Locale;
 
+import org.jivesoftware.smack.util.Objects;
 import org.jivesoftware.smack.util.XmlStringBuilder;
 
 /**
@@ -84,10 +85,7 @@ public abstract class IQ extends Packet {
      * @param type the type of the IQ packet.
      */
     public void setType(Type type) {
-        if (type == null) {
+        this.type = Objects.requireNonNull(type, "type must not be null");
-            throw new IllegalArgumentException("type must not be null");
-        }
-        this.type = type;
     }
 
     /**

smack-core/src/main/java/org/jivesoftware/smack/sasl/packet/SaslStreamElements.java

@@ -21,6 +21,7 @@ import java.util.Map;
 import org.jivesoftware.smack.packet.AbstractError;
 import org.jivesoftware.smack.packet.PlainStreamElement;
 import org.jivesoftware.smack.sasl.SASLError;
+import org.jivesoftware.smack.util.Objects;
 import org.jivesoftware.smack.util.StringUtils;
 import org.jivesoftware.smack.util.XmlStringBuilder;
 
@@ -37,14 +38,9 @@ public class SaslStreamElements {
         private final String authenticationText;
 
         public AuthMechanism(String mechanism, String authenticationText) {
-            if (mechanism == null) {
+            this.mechanism = Objects.requireNonNull(mechanism, "SASL mechanism shouldn't be null.");
-                throw new NullPointerException("SASL mechanism shouldn't be null.");
+            this.authenticationText = StringUtils.requireNotNullOrEmpty(authenticationText,
-            }
+                            "SASL authenticationText must not be null or empty (RFC6120 6.4.2)");
-            if (StringUtils.isNullOrEmpty(authenticationText)) {
-                throw new IllegalArgumentException("SASL authenticationText must not be null or empty (RFC6120 6.4.2)");
-            }
-            this.mechanism = mechanism;
-            this.authenticationText = authenticationText;
         }
 
         @Override

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

@@ -0,0 +1,27 @@
+/**
+ *
+ * Copyright 2015 Florian Schmaus
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smack.util;
+
+public class Objects {
+
+    public static <T> T requireNonNull(T obj, String message) {
+        if (obj == null) {
+            throw new IllegalArgumentException(message);
+        }
+        return obj;
+    }
+}

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

@@ -257,4 +257,11 @@ public class StringUtils {
         }
         return csOne.toString().compareTo(csTwo.toString());
     }
+
+    public static <CS extends CharSequence> CS requireNotNullOrEmpty(CS cs, String message) {
+        if (isNullOrEmpty(cs)) {
+            throw new IllegalArgumentException(message);
+        }
+        return cs;
+    }
 }

smack-core/src/main/java/org/jivesoftware/smack/util/dns/HostAddress.java

@@ -17,6 +17,7 @@
 package org.jivesoftware.smack.util.dns;
 
 import org.jivesoftware.smack.SmackException.ConnectionException;
+import org.jivesoftware.smack.util.Objects;
 
 public class HostAddress {
     private final String fqdn;
@@ -42,8 +43,7 @@ public class HostAddress {
      * @throws IllegalArgumentException If the fqdn is null or port is out of valid range (0 - 65535).
      */
     public HostAddress(String fqdn, int port) {
-        if (fqdn == null)
+        Objects.requireNonNull(fqdn, "FQDN is null");
-            throw new IllegalArgumentException("FQDN is null");
         if (port < 0 || port > 65535)
             throw new IllegalArgumentException(
                     "Port must be a 16-bit unsiged integer (i.e. between 0-65535. Port was: " + port);

smack-core/src/main/java/org/jivesoftware/smack/util/stringencoder/Base64.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright © 2014 Florian Schmaus
+ * Copyright © 2014-2015 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,6 +18,7 @@ package org.jivesoftware.smack.util.stringencoder;
 
 import java.io.UnsupportedEncodingException;
 
+import org.jivesoftware.smack.util.Objects;
 import org.jivesoftware.smack.util.StringUtils;
 
 public class Base64 {
@@ -25,9 +26,7 @@ public class Base64 {
     private static Base64.Encoder base64encoder;
 
     public static void setEncoder(Base64.Encoder encoder) {
-        if (encoder == null) {
+        Objects.requireNonNull(encoder, "encoder must no be null");
-            throw new IllegalArgumentException("encoder must no be null");
-        }
         base64encoder = encoder;
     }
 

smack-core/src/main/java/org/jivesoftware/smack/util/stringencoder/Base64UrlSafeEncoder.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright © 2014 Florian Schmaus
+ * Copyright © 2014-2015 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,14 +16,14 @@
  */
 package org.jivesoftware.smack.util.stringencoder;
 
+import org.jivesoftware.smack.util.Objects;
+
 
 public class Base64UrlSafeEncoder {
     private static StringEncoder base64UrlSafeEncoder;
 
     public static void setEncoder(StringEncoder encoder) {
-        if (encoder == null) {
+        Objects.requireNonNull(encoder, "encoder must no be null");
-            throw new IllegalArgumentException("encoder must no be null");
-        }
         base64UrlSafeEncoder = encoder;
     }
 

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

@@ -316,14 +316,8 @@ public class DiscoverInfo extends IQ implements Cloneable {
          * @param lang the entity's lang.
          */
         public Identity(String category, String type, String name, String lang) {
-            if (StringUtils.isNullOrEmpty(category)) {
+            this.category = StringUtils.requireNotNullOrEmpty(category, "category cannot be null");
-                throw new IllegalArgumentException("category cannot be null");
+            this.type = StringUtils.requireNotNullOrEmpty(type, "type cannot be null");
-            }
-            if (StringUtils.isNullOrEmpty(type)) {
-                throw new IllegalArgumentException("type cannot be null");
-            }
-            this.category = category;
-            this.type = type;
             this.key = XmppStringUtils.generateKey(category, type);
             this.name = name;
             this.lang = lang;
@@ -493,9 +487,7 @@ public class DiscoverInfo extends IQ implements Cloneable {
          * @param variable the feature's variable.
          */
         public Feature(String variable) {
-            if (variable == null)
+            this.variable = StringUtils.requireNotNullOrEmpty(variable, "variable cannot be null");
-                throw new IllegalArgumentException("variable cannot be null");
-            this.variable = variable;
         }
 
         /**

smack-extensions/src/main/java/org/jivesoftware/smackx/iqversion/packet/Version.java

@@ -20,6 +20,7 @@ package org.jivesoftware.smackx.iqversion.packet;
 
 import org.jivesoftware.smack.packet.IQ;
 import org.jivesoftware.smack.packet.Packet;
+import org.jivesoftware.smack.util.StringUtils;
 
 /**
  * A Version IQ packet, which is used by XMPP clients to discover version information
@@ -85,16 +86,9 @@ public class Version extends IQ {
      */
     public Version(String name, String version, String os) {
         super(ELEMENT, NAMESPACE);
-        if (name == null)
-        {
-            throw new IllegalArgumentException("name must not be null");
-        }
-        if (version == null) {
-            throw new IllegalArgumentException("version must not be null");
-        }
         this.setType(IQ.Type.result);
-        this.name = name;
+        this.name = StringUtils.requireNotNullOrEmpty(name, "name must not be null");
-        this.version = version;
+        this.version = StringUtils.requireNotNullOrEmpty(version, "version must not be null");
         this.os = os;
     }
 

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

@@ -274,9 +274,7 @@ public class MultiUserChat {
     private Presence enter(String nickname, String password, DiscussionHistory history,
                     long timeout) throws NotConnectedException, NoResponseException,
                     XMPPErrorException {
-        if (StringUtils.isNullOrEmpty(nickname)) {
+        StringUtils.requireNotNullOrEmpty(nickname, "Nickname must not be null or blank.");
-            throw new IllegalArgumentException("Nickname must not be null or blank.");
-        }
         // We enter a room by sending a presence packet where the "to"
         // field is in the form "roomName@service/nickname"
         Presence joinPresence = new Presence(Presence.Type.available);
@@ -844,9 +842,7 @@ public class MultiUserChat {
      * @throws NotConnectedException 
      */
     public void changeNickname(String nickname) throws NoResponseException, XMPPErrorException, NotConnectedException  {
-        if (StringUtils.isNullOrEmpty(nickname)) {
+        StringUtils.requireNotNullOrEmpty(nickname, "Nickname must not be null or blank.");
-            throw new IllegalArgumentException("Nickname must not be null or blank.");
-        }
         // Check that we already have joined the room before attempting to change the
         // nickname.
         if (!joined) {
@@ -881,9 +877,7 @@ public class MultiUserChat {
      * @throws NotConnectedException 
      */
     public void changeAvailabilityStatus(String status, Presence.Mode mode) throws NotConnectedException {
-        if (StringUtils.isNullOrEmpty(nickname)) {
+        StringUtils.requireNotNullOrEmpty(nickname, "Nickname must not be null or blank.");
-            throw new IllegalArgumentException("Nickname must not be null or blank.");
-        }
         // Check that we already have joined the room before attempting to change the
         // availability status.
         if (!joined) {