/** * 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; } }