/**
* Selects an appropriate stream negotiator after examining the incoming file transfer request.
*
* @param request The related file transfer request.
* @return The file transfer object that handles the transfer
* @throws XMPPException If there are either no stream methods contained in the packet, or there
* is not an appropriate stream method.
*/
public StreamNegotiator selectStreamNegotiator(FileTransferRequest request) throws XMPPException {
final StreamInitiation si = request.getStreamInitiation();
final FormField streamMethodField = getStreamMethodField(si.getFeatureNegotiationForm());
if (streamMethodField == null) {
final String errorMessage = "No stream methods contained in packet.";
final XMPPError error = new XMPPError(XMPPError.Condition.bad_request, errorMessage);
final IQ iqPacket = createIQ(si.getPacketID(), si.getFrom(), si.getTo(), IQ.Type.ERROR);
iqPacket.setError(error);
connection.sendPacket(iqPacket);
throw new XMPPException(errorMessage, error);
}
// select the appropriate protocol
StreamNegotiator selectedStreamNegotiator;
try {
selectedStreamNegotiator = getNegotiator(streamMethodField);
} catch (final XMPPException e) {
final IQ iqPacket = createIQ(si.getPacketID(), si.getFrom(), si.getTo(), IQ.Type.ERROR);
iqPacket.setError(e.getXMPPError());
connection.sendPacket(iqPacket);
throw e;
}
// return the appropriate negotiator
return selectedStreamNegotiator;
}
/**
* Send a request to another user to send them a file. The other user has the option of,
* accepting, rejecting, or not responding to a received file transfer request.
*
* <p>If they accept, the packet will contain the other user's chosen stream type to send the file
* across. The two choices this implementation provides to the other user for file transfer are <a
* href="http://www.jabber.org/jeps/jep-0065.html">SOCKS5 Bytestreams</a>, which is the preferred
* method of transfer, and <a href="http://www.jabber.org/jeps/jep-0047.html">In-Band
* Bytestreams</a>, which is the fallback mechanism.
*
* <p>The other user may choose to decline the file request if they do not desire the file, their
* client does not support JEP-0096, or if there are no acceptable means to transfer the file.
*
* <p>Finally, if the other user does not respond this method will return null after the specified
* timeout.
*
* @param userID The userID of the user to whom the file will be sent.
* @param streamID The unique identifier for this file transfer.
* @param fileName The name of this file. Preferably it should include an extension as it is used
* to determine what type of file it is.
* @param size The size, in bytes, of the file.
* @param desc A description of the file.
* @param responseTimeout The amount of time, in milliseconds, to wait for the remote user to
* respond. If they do not respond in time, this
* @return Returns the stream negotiator selected by the peer.
* @throws XMPPException Thrown if there is an error negotiating the file transfer.
*/
public StreamNegotiator negotiateOutgoingTransfer(
final String userID,
final String streamID,
final String fileName,
final long size,
final String desc,
int responseTimeout)
throws XMPPException {
final StreamInitiation si = new StreamInitiation();
si.setSesssionID(streamID);
si.setMimeType(URLConnection.guessContentTypeFromName(fileName));
final StreamInitiation.File siFile = new StreamInitiation.File(fileName, size);
siFile.setDesc(desc);
si.setFile(siFile);
si.setFeatureNegotiationForm(createDefaultInitiationForm());
si.setFrom(connection.getUser());
si.setTo(userID);
si.setType(IQ.Type.SET);
final PacketCollector collector =
connection.createPacketCollector(new PacketIDFilter(si.getPacketID()));
connection.sendPacket(si);
final Packet siResponse = collector.nextResult(responseTimeout);
collector.cancel();
if (siResponse instanceof IQ) {
final IQ iqResponse = (IQ) siResponse;
if (iqResponse.getType().equals(IQ.Type.RESULT)) {
final StreamInitiation response = (StreamInitiation) siResponse;
return getOutgoingNegotiator(getStreamMethodField(response.getFeatureNegotiationForm()));
} else if (iqResponse.getType().equals(IQ.Type.ERROR)) {
throw new XMPPException(iqResponse.getError());
} else {
throw new XMPPException("File transfer response unreadable");
}
} else {
return null;
}
}