StreamNegotiator.java
/**
*
* Copyright 2003-2006 Jive Software.
*
* 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.smackx.filetransfer;
import java.io.InputStream;
import java.io.OutputStream;
import org.jivesoftware.smack.Manager;
import org.jivesoftware.smack.SmackException;
import org.jivesoftware.smack.SmackException.NoResponseException;
import org.jivesoftware.smack.SmackException.NotConnectedException;
import org.jivesoftware.smack.XMPPConnection;
import org.jivesoftware.smack.XMPPException;
import org.jivesoftware.smack.XMPPException.XMPPErrorException;
import org.jivesoftware.smack.packet.IQ;
import org.jivesoftware.smack.packet.Stanza;
import org.jivesoftware.smack.util.EventManger;
import org.jivesoftware.smackx.si.packet.StreamInitiation;
import org.jivesoftware.smackx.xdata.FormField;
import org.jivesoftware.smackx.xdata.ListSingleFormField;
import org.jivesoftware.smackx.xdata.packet.DataForm;
import org.jxmpp.jid.Jid;
/**
* After the file transfer negotiation process is completed according to
* XEP-0096, the negotiation process is passed off to a particular stream
* negotiator. The stream negotiator will then negotiate the chosen stream and
* return the stream to transfer the file.
*
* @author Alexander Wenckus
*/
public abstract class StreamNegotiator extends Manager {
protected StreamNegotiator(XMPPConnection connection) {
super(connection);
}
/**
* A event manager for stream initiation requests send to us.
* <p>
* Those are typical XEP-45 Open or XEP-65 Bytestream IQ requests. The even key is in the format
* "initiationFrom + '\t' + streamId"
* </p>
*/
// TODO This field currently being static is considered a quick hack. Ideally this should take
// the local connection into account, for example by changing the key to
// "localJid + '\t' + initiationFrom + '\t' + streamId" or making the field non-static (but then
// you need to provide access to the InitiationListeners, which could get tricky)
protected static final EventManger<String, IQ, SmackException.NotConnectedException> initationSetEvents = new EventManger<>();
/**
* Creates the initiation acceptance stanza to forward to the stream
* initiator.
*
* @param streamInitiationOffer The offer from the stream initiator to connect for a stream.
* @param namespace The namespace that relates to the accepted means of transfer.
* @return The response to be forwarded to the initiator.
*/
protected static StreamInitiation createInitiationAccept(
StreamInitiation streamInitiationOffer, String namespace) {
StreamInitiation response = new StreamInitiation();
response.setTo(streamInitiationOffer.getFrom());
response.setFrom(streamInitiationOffer.getTo());
response.setType(IQ.Type.result);
response.setStanzaId(streamInitiationOffer.getStanzaId());
DataForm.Builder form = DataForm.builder();
ListSingleFormField.Builder field = FormField.listSingleBuilder(
FileTransferNegotiator.STREAM_DATA_FIELD_NAME);
field.setValue(namespace);
form.addField(field.build());
response.setFeatureNegotiationForm(form.build());
return response;
}
protected final IQ initiateIncomingStream(final XMPPConnection connection, StreamInitiation initiation)
throws NoResponseException, XMPPErrorException, NotConnectedException {
final StreamInitiation response = createInitiationAccept(initiation,
getNamespace());
newStreamInitiation(initiation.getFrom(), initiation.getSessionID());
final String eventKey = initiation.getFrom().toString() + '\t' + initiation.getSessionID();
IQ streamMethodInitiation;
try {
streamMethodInitiation = initationSetEvents.performActionAndWaitForEvent(eventKey, connection.getReplyTimeout(), new EventManger.Callback<NotConnectedException>() {
@Override
public void action() throws NotConnectedException {
try {
connection.sendStanza(response);
}
catch (InterruptedException e) {
// Ignore
}
}
});
}
catch (InterruptedException e) {
// TODO remove this try/catch once merged into 4.2's master branch
throw new IllegalStateException(e);
}
if (streamMethodInitiation == null) {
throw NoResponseException.newWith(connection, "stream initiation");
}
XMPPErrorException.ifHasErrorThenThrow(streamMethodInitiation);
return streamMethodInitiation;
}
/**
* Signal that a new stream initiation arrived. The negotiator may needs to prepare for it.
*
* @param from The initiator of the file transfer.
* @param streamID The stream ID related to the transfer.
*/
protected abstract void newStreamInitiation(Jid from, String streamID);
abstract InputStream negotiateIncomingStream(Stanza streamInitiation) throws XMPPErrorException,
InterruptedException, SmackException;
/**
* This method handles the file stream download negotiation process. The
* appropriate stream negotiator's initiate incoming stream is called after
* an appropriate file transfer method is selected. The manager will respond
* to the initiator with the selected means of transfer, then it will handle
* any negotiation specific to the particular transfer method. This method
* returns the InputStream, ready to transfer the file.
*
* @param initiation The initiation that triggered this download.
* @return After the negotiation process is complete, the InputStream to
* write a file to is returned.
* @throws XMPPErrorException If an error occurs during this process an XMPPException is
* thrown.
* @throws InterruptedException If thread is interrupted.
* @throws SmackException if Smack detected an exceptional situation.
*/
public abstract InputStream createIncomingStream(StreamInitiation initiation)
throws XMPPErrorException, InterruptedException, SmackException;
/**
* This method handles the file upload stream negotiation process. The
* particular stream negotiator is determined during the file transfer
* negotiation process. This method returns the OutputStream to transmit the
* file to the remote user.
*
* @param streamID The streamID that uniquely identifies the file transfer.
* @param initiator The fully-qualified JID of the initiator of the file transfer.
* @param target The fully-qualified JID of the target or receiver of the file
* transfer.
* @return The negotiated stream ready for data.
* @throws SmackException if Smack detected an exceptional situation.
* @throws XMPPException if an XMPP protocol error was received.
* @throws InterruptedException if the calling thread was interrupted.
*/
public abstract OutputStream createOutgoingStream(String streamID,
Jid initiator, Jid target) throws SmackException, XMPPException, InterruptedException;
/**
* Returns the XMPP namespace reserved for this particular type of file
* transfer.
*
* @return Returns the XMPP namespace reserved for this particular type of
* file transfer.
*/
public abstract String getNamespace();
public static void signal(String eventKey, IQ eventValue) {
initationSetEvents.signalEvent(eventKey, eventValue);
}
}