Add support for XEP-0059: Result Set Management

SMACK-581

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

@@ -17,6 +17,7 @@
 
 package org.jivesoftware.smack.packet;
 
+import org.jivesoftware.smack.util.PacketUtil;
 import org.jivesoftware.smack.util.StringUtils;
 import org.jivesoftware.smack.util.XmlStringBuilder;
 
@@ -232,19 +233,11 @@ public abstract class Packet extends TopLevelStreamElement {
      * @param namespace the XML element namespace of the packet extension.
      * @return the extension, or <tt>null</tt> if it doesn't exist.
      */
-    @SuppressWarnings("unchecked")
     public <PE extends PacketExtension> PE getExtension(String elementName, String namespace) {
         if (namespace == null) {
             return null;
         }
-        for (PacketExtension ext : packetExtensions) {
-            if ((elementName == null || elementName.equals(ext.getElementName()))
-                    && namespace.equals(ext.getNamespace()))
-            {
-                return (PE) ext;
-            }
-        }
-        return null;
+        return PacketUtil.packetExtensionfromCollection(packetExtensions, elementName, namespace);
     }
 
     /**

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

@@ -0,0 +1,38 @@
+/**
+ *
+ * Copyright © 2014 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;
+
+import java.util.Collection;
+
+import org.jivesoftware.smack.packet.PacketExtension;
+
+public class PacketUtil {
+
+    @SuppressWarnings("unchecked")
+    public static <PE extends PacketExtension> PE packetExtensionfromCollection(
+                    Collection<PacketExtension> collection, String element,
+                    String namespace) {
+        for (PacketExtension packetExtension : collection) {
+            if ((element == null || packetExtension.getElementName().equals(
+                            element))
+                            && packetExtension.getNamespace().equals(namespace)) {
+                return (PE) packetExtension;
+            }
+        }
+        return null;
+    }
+}

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

@@ -16,6 +16,7 @@
  */
 package org.jivesoftware.smack.util;
 
+import java.io.IOException;
 import java.util.Locale;
 
 import org.xmlpull.v1.XmlPullParser;
@@ -77,6 +78,11 @@ public class ParserUtils {
         }
     }
 
+    public static int getIntegerFromNextText(XmlPullParser parser) throws XmlPullParserException, IOException {
+        String intString = parser.nextText();
+        return Integer.valueOf(intString);
+    }
+
     public static Long getLongAttribute(XmlPullParser parser, String name) {
         String valueString = parser.getAttributeValue("", name);
         if (valueString == null)

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

@@ -86,6 +86,13 @@ public class XmlStringBuilder implements Appendable, CharSequence {
         return this;
     }
 
+    public XmlStringBuilder optIntElement(String name, int value) {
+        if (value >= 0) {
+            element(name, String.valueOf(value));
+        }
+        return this;
+    }
+
     public XmlStringBuilder halfOpenElement(String name) {
         sb.append('<').append(name);
         return this;