/**
* $RCSfile$
* $Revision$
* $Date$
*
* Copyright 2003-2006 Jive Software.
*
* All rights reserved. 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 org.jivesoftware.smack.PacketCollector;
import org.jivesoftware.smack.SmackConfiguration;
import org.jivesoftware.smack.Connection;
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.XMPPError;
import org.jivesoftware.smackx.Form;
import org.jivesoftware.smackx.FormField;
import org.jivesoftware.smackx.packet.DataForm;
import org.jivesoftware.smackx.packet.StreamInitiation;
import java.io.InputStream;
import java.io.OutputStream;
/**
* After the file transfer negotiation process is completed according to
* JEP-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 {
/**
* Creates the initiation acceptance packet to forward to the stream
* initiator.
*
* @param streamInitiationOffer The offer from the stream initiator to connect for a stream.
* @param namespaces The namespace that relates to the accepted means of transfer.
* @return The response to be forwarded to the initiator.
*/
public StreamInitiation createInitiationAccept(
StreamInitiation streamInitiationOffer, String[] namespaces)
{
StreamInitiation response = new StreamInitiation();
response.setTo(streamInitiationOffer.getFrom());
response.setFrom(streamInitiationOffer.getTo());
response.setType(IQ.Type.RESULT);
response.setPacketID(streamInitiationOffer.getPacketID());
DataForm form = new DataForm(Form.TYPE_SUBMIT);
FormField field = new FormField(
FileTransferNegotiator.STREAM_DATA_FIELD_NAME);
for (String namespace : namespaces) {
field.addValue(namespace);
}
form.addField(field);
response.setFeatureNegotiationForm(form);
return response;
}
public IQ createError(String from, String to, String packetID, XMPPError xmppError) {
IQ iq = FileTransferNegotiator.createIQ(packetID, to, from, IQ.Type.ERROR);
iq.setError(xmppError);
return iq;
}
Packet initiateIncomingStream(Connection connection, StreamInitiation initiation) throws XMPPException {
StreamInitiation response = createInitiationAccept(initiation,
getNamespaces());
// establish collector to await response
PacketCollector collector = connection
.createPacketCollector(getInitiationPacketFilter(initiation.getFrom(), initiation.getSessionID()));
connection.sendPacket(response);
Packet streamMethodInitiation = collector
.nextResult(SmackConfiguration.getPacketReplyTimeout());
collector.cancel();
if (streamMethodInitiation == null) {
throw new XMPPException("No response from file transfer initiator");
}
return streamMethodInitiation;
}
/**
* Returns the packet filter that will return the initiation packet for the appropriate stream
* initiation.
*
* @param from The initiator of the file transfer.
* @param streamID The stream ID related to the transfer.
* @return The <b><i>PacketFilter</b></i> that will return the packet relatable to the stream
* initiation.
*/
public abstract PacketFilter getInitiationPacketFilter(String from, String streamID);
abstract InputStream negotiateIncomingStream(Packet streamInitiation) throws XMPPException,
InterruptedException;
/**
* 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 XMPPException If an error occurs during this process an XMPPException is
* thrown.
* @throws InterruptedException If thread is interrupted.
*/
public abstract InputStream createIncomingStream(StreamInitiation initiation)
throws XMPPException, InterruptedException;
/**
* 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 XMPPException If an error occurs during the negotiation process an
* exception will be thrown.
*/
public abstract OutputStream createOutgoingStream(String streamID,
String initiator, String target) throws XMPPException;
/**
* 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[] getNamespaces();
/**
* Cleanup any and all resources associated with this negotiator.
*/
public abstract void cleanup();
}