Improve Roster, RosterEntry and RosterGroup

Use final where possible, add javadoc. Fix duplicate comment in
Roster.

Use createPacketCollectorAndSend(packet).nextResultOrThrow when
possible, and only set the entry name if the IQ set is successful.

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

@@ -944,9 +944,7 @@ public class Roster extends Manager {
             unfiledEntries.remove(entry);
         }
 
-        // Add the user to the new groups
+        // Add the entry/user to the groups
-
-        // Add the entry to the groups
         List<String> newGroupNames = new ArrayList<String>();
         for (String groupName : item.getGroupNames()) {
             // Add the group name to the list.

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

@@ -22,8 +22,10 @@ import java.util.Collection;
 import java.util.Iterator;
 import java.util.List;
 
+import org.jivesoftware.smack.SmackException.NoResponseException;
 import org.jivesoftware.smack.XMPPConnection;
 import org.jivesoftware.smack.SmackException.NotConnectedException;
+import org.jivesoftware.smack.XMPPException.XMPPErrorException;
 import org.jivesoftware.smack.packet.IQ;
 import org.jivesoftware.smack.roster.packet.RosterPacket;
 
@@ -36,7 +38,11 @@ import org.jivesoftware.smack.roster.packet.RosterPacket;
  */
 public class RosterEntry {
 
-    private String user;
+    /**
+     * The JID of the entity/user.
+     */
+    private final String user;
+
     private String name;
     private RosterPacket.ItemType type;
     private RosterPacket.ItemStatus status;
@@ -85,17 +91,22 @@ public class RosterEntry {
      *
      * @param name the name.
      * @throws NotConnectedException 
+     * @throws XMPPErrorException 
+     * @throws NoResponseException 
      */
-    public void setName(String name) throws NotConnectedException {
+    public void setName(String name) throws NotConnectedException, NoResponseException, XMPPErrorException {
         // Do nothing if the name hasn't changed.
         if (name != null && name.equals(this.name)) {
             return;
         }
-        this.name = name;
+
         RosterPacket packet = new RosterPacket();
         packet.setType(IQ.Type.set);
         packet.addRosterItem(toRosterItem(this));
-        connection.sendPacket(packet);
+        connection.createPacketCollectorAndSend(packet).nextResultOrThrow();
+
+        // We have received a result response to the IQ set, the name was successfully changed
+        this.name = name;
     }
 
     /**

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

@@ -40,8 +40,8 @@ import org.jxmpp.util.XmppStringUtils;
  */
 public class RosterGroup {
 
-    private String name;
+    private final String name;
-    private XMPPConnection connection;
+    private final XMPPConnection connection;
     private final Set<RosterEntry> entries;
 
     /**
@@ -73,8 +73,10 @@ public class RosterGroup {
      *
      * @param name the name of the group.
      * @throws NotConnectedException 
+     * @throws XMPPErrorException 
+     * @throws NoResponseException 
      */
-    public void setName(String name) throws NotConnectedException {
+    public void setName(String name) throws NotConnectedException, NoResponseException, XMPPErrorException {
         synchronized (entries) {
             for (RosterEntry entry : entries) {
                 RosterPacket packet = new RosterPacket();
@@ -83,7 +85,7 @@ public class RosterGroup {
                 item.removeGroupName(this.name);
                 item.addGroupName(name);
                 packet.addRosterItem(item);
-                connection.sendPacket(packet);
+                connection.createPacketCollectorAndSend(packet).nextResultOrThrow();
             }
         }
     }