Rework XMPP Error class design

Introduce AbstractError, change 'Conditions' to enums. Because of
AbstractError, it was necessary that PlainStreamElement and
TopLevelStreamElement becomes an interface. Thus the implementation of
TopLevelStreamElement.toString() had to be removed.

This adds

- policy-violation
- unexpected-request

to XMPPError.Condition, and removes the

- payment-required
- remote-server-error
- unexpected-condition
- request-timeout

Conditions

The file transfer code does now no longer throw XMPPErrorExceptions, but
SmackExceptions.

Fixes SMACK-608. Makes it possible to resolves SMACK-386.

smack-jingle-old/src/main/java/org/jivesoftware/smackx/jingleold/JingleSession.java

@@ -33,7 +33,6 @@ import org.jivesoftware.smack.XMPPException;
 import org.jivesoftware.smack.filter.PacketFilter;
 import org.jivesoftware.smack.packet.IQ;
 import org.jivesoftware.smack.packet.Packet;
-import org.jivesoftware.smack.packet.PacketExtension;
 import org.jivesoftware.smack.packet.XMPPError;
 import org.jivesoftware.smackx.jingleold.listeners.JingleListener;
 import org.jivesoftware.smackx.jingleold.listeners.JingleMediaListener;
@@ -1030,9 +1029,8 @@ public class JingleSession extends JingleNegotiator implements MediaReceivedList
     public IQ createJingleError(IQ iq, JingleError jingleError) {
         IQ errorPacket = null;
         if (jingleError != null) {
-            List<PacketExtension> extList = new ArrayList<PacketExtension>();
-            extList.add(jingleError);
-            XMPPError error = new XMPPError(XMPPError.Type.CANCEL, jingleError.toString(), "", extList);
+            // TODO This is wrong according to XEP-166 § 10, but this jingle implementation is deprecated anyways
+            XMPPError error = new XMPPError(XMPPError.Condition.undefined_condition, jingleError);
 
             errorPacket = IQ.createErrorResponse(iq, error);
 

smack-jingle-old/src/main/java/org/jivesoftware/smackx/jingleold/media/MediaNegotiator.java

@@ -113,7 +113,7 @@ public class MediaNegotiator extends JingleNegotiator {
             setNegotiatorState(JingleNegotiatorState.FAILED);
             triggerMediaClosed(getBestCommonAudioPt());
             // This next line seems wrong, and may subvert the normal closing process.
-            throw new JingleException(iq.getError().getMessage());
+            throw new JingleException(iq.getError().getDescriptiveText());
         } else if (iq.getType().equals(IQ.Type.result)) {
             // Process ACKs
             if (isExpectedId(iq.getPacketID())) {

smack-jingle-old/src/main/java/org/jivesoftware/smackx/jingleold/nat/TransportNegotiator.java

@@ -603,7 +603,7 @@ public abstract class TransportNegotiator extends JingleNegotiator {
                 setNegotiatorState(JingleNegotiatorState.FAILED);
                 triggerTransportClosed(null);
                 // This next line seems wrong, and may subvert the normal closing process.
-                throw new JingleException(iq.getError().getMessage());
+                throw new JingleException(iq.getError().getDescriptiveText());
             } else if (iq.getType().equals(IQ.Type.result)) {
                 // Process ACKs
                 if (isExpectedId(iq.getPacketID())) {