Sending upstream messages

Although we are able to receive the chat group messages, we are not able to interact with the message stream from the application. Additionally, to send and process upstream messages with the GCM platform, an application server that implements the XMPP Connection Server protocol is required to connect to the GCM servers and receive upstream XMPP messages.

To deal with our group messages we built a very basic XMPP server that processes the upstream messages from the device and forwards the message to the topic message.

The basic XMPP Server source code is available from the Packt Publishing website. Grab it from the Packt website, and, before you run it, update the static fields with your SenderID and your ServerKey in the GCMServer.java class file.

private static final String SENDER_ID = "<YOUR_SENDER_ID>"; 
private static final String SERVER_KEY = "<SERVER_KEY>";

The server will connect to the GCM platform, initiate a XMPP session, and process all the...