001/**
002 *
003 * Copyright 2003-2006 Jive Software.
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.jivesoftware.smackx.filetransfer;
018
019import java.io.InputStream;
020import java.io.OutputStream;
021
022import org.jivesoftware.smack.SmackException;
023import org.jivesoftware.smack.XMPPConnection;
024import org.jivesoftware.smack.XMPPException;
025import org.jivesoftware.smack.XMPPException.XMPPErrorException;
026import org.jivesoftware.smack.packet.IQ;
027import org.jivesoftware.smack.packet.Stanza;
028
029import org.jivesoftware.smackx.bytestreams.ibb.packet.Open;
030import org.jivesoftware.smackx.bytestreams.socks5.packet.Bytestream;
031import org.jivesoftware.smackx.si.packet.StreamInitiation;
032
033import org.jxmpp.jid.Jid;
034
035
036/**
037 * The fault tolerant negotiator takes two stream negotiators, the primary and the secondary
038 * negotiator. If the primary negotiator fails during the stream negotiation process, the second
039 * negotiator is used.
040 */
041public class FaultTolerantNegotiator extends StreamNegotiator {
042
043    private final StreamNegotiator primaryNegotiator;
044    private final StreamNegotiator secondaryNegotiator;
045
046    public FaultTolerantNegotiator(XMPPConnection connection, StreamNegotiator primary,
047            StreamNegotiator secondary) {
048        super(connection);
049        this.primaryNegotiator = primary;
050        this.secondaryNegotiator = secondary;
051    }
052
053    @Override
054    public void newStreamInitiation(Jid from, String streamID) {
055        primaryNegotiator.newStreamInitiation(from, streamID);
056        secondaryNegotiator.newStreamInitiation(from, streamID);
057    }
058
059    @Override
060    InputStream negotiateIncomingStream(Stanza streamInitiation) {
061        throw new UnsupportedOperationException("Negotiation only handled by create incoming " +
062                "stream method.");
063    }
064
065    @Override
066    public InputStream createIncomingStream(final StreamInitiation initiation) throws SmackException, XMPPErrorException, InterruptedException {
067        // This could be either an xep47 ibb 'open' iq or an xep65 streamhost iq
068        IQ initiationSet = initiateIncomingStream(connection(), initiation);
069
070        StreamNegotiator streamNegotiator = determineNegotiator(initiationSet);
071
072        return streamNegotiator.negotiateIncomingStream(initiationSet);
073    }
074
075    private StreamNegotiator determineNegotiator(Stanza streamInitiation) {
076        if (streamInitiation instanceof Bytestream) {
077            return primaryNegotiator;
078        } else if (streamInitiation instanceof Open) {
079            return secondaryNegotiator;
080        } else {
081            throw new IllegalStateException("Unknown stream initiation type");
082        }
083    }
084
085    @Override
086    public OutputStream createOutgoingStream(String streamID, Jid initiator, Jid target)
087                    throws SmackException, XMPPException, InterruptedException {
088        OutputStream stream;
089        try {
090            stream = primaryNegotiator.createOutgoingStream(streamID, initiator, target);
091        }
092        catch (Exception ex) {
093            stream = secondaryNegotiator.createOutgoingStream(streamID, initiator, target);
094        }
095
096        return stream;
097    }
098
099    @Override
100    public String[] getNamespaces() {
101        String[] primary = primaryNegotiator.getNamespaces();
102        String[] secondary = secondaryNegotiator.getNamespaces();
103
104        String[] namespaces = new String[primary.length + secondary.length];
105        System.arraycopy(primary, 0, namespaces, 0, primary.length);
106        System.arraycopy(secondary, 0, namespaces, primary.length, secondary.length);
107
108        return namespaces;
109    }
110
111}