File Transfer. (SMACK-72) (SMACK-122)

git-svn-id: http://svn.igniterealtime.org/svn/repos/smack/trunk@3395 b35dd754-fafc-0310-a699-88a17e54d16e

source/org/jivesoftware/smackx/filetransfer/StreamNegotiator.java

@@ -0,0 +1,105 @@
+/**
+ * 
+ */
+package org.jivesoftware.smackx.filetransfer;
+
+import java.io.InputStream;
+import java.io.OutputStream;
+
+import org.jivesoftware.smack.XMPPException;
+import org.jivesoftware.smack.packet.IQ;
+import org.jivesoftware.smackx.Form;
+import org.jivesoftware.smackx.FormField;
+import org.jivesoftware.smackx.packet.DataForm;
+import org.jivesoftware.smackx.packet.StreamInitiation;
+
+/**
+ * After the file transfer negotiation process is completed according to
+ * JEP-0096, the negotation 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 initatior 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 initator.
+	 */
+	public StreamInitiation createInitiationAccept(
+			StreamInitiation streamInitiationOffer, String namespace) {
+		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);
+		field.addValue(namespace);
+		form.addField(field);
+
+		response.setFeatureNegotiationForm(form);
+		return response;
+	}
+
+    /**
+	 * 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 initatior with the selected means of transfer, then it will handle
+	 * any negotation specific to the particular transfer method. This method
+	 * returns the InputStream, ready to transfer the file.
+	 * 
+	 * @param initiation
+	 *            The initation that triggered this download.
+	 * @return After the negotation 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.
+	 */
+	public abstract InputStream initiateIncomingStream(
+			StreamInitiation initiation) throws XMPPException;
+
+	/**
+	 * 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 reciever 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 initiateOutgoingStream(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 getNamespace();
+
+}