Implementing Android GCM in a different package other than the main application package

There is something you need to be aware of if you are placing your GCM (Google Cloud Messaging, aka push notifications) service (the one extending from GCMBaseIntentService) in a package other than the main application package. The default implementation of the GCMBroadcastReceiver class, whcih is part of the GCM library assumes that your service is going to be in the main application package. If the service is in a different package though, then it will not be able to be started by the broadcast receiver and if you are debugging your app it will look like your app requests a Registration ID from the Google servers, but then everything dies off and you are not getting a response back.

What you need to do in this case is extend the GCMBroadcastReceiver class and override the getGCMIntentServiceClassName method to return the package name of the service and the service class name. So for example, if your service was called GCMIntentService in package com.mycompany.mainpackage.somepackage, you would return: “com.mycompany.mainpackage.somepackage.GCMIntentService”. Here is an example of the extanded GCMBroadcastReceiver class:

public class GCMMyBoadcastReceiver extends GCMBroadcastReceiver {
	protected String getGCMIntentServiceClassName(Context contest) {
		return "com.mycompany.mainpackage.somepackage.GCMIntentService";
	}
}

Also, do not forget to update your manifest file to make sure that the new extended broadcast receiver is used:

<receiver android:name="com.mycompany.mainpackage.somepackage.GCMMyBoadcastReceiver" android:permission="com.google.android.c2dm.permission.SEND">
    <intent-filter>
        <action android:name="com.google.android.c2dm.intent.RECEIVE" />
	<action android:name="com.google.android.c2dm.intent.REGISTRATION" />
        <category android:name="com.mycompany.mainpackage" />
   </intent-filter>
</receiver>

This little detail wasted a coule of hours of my time trying to figure out what I did wrong. Unfortunatly this detial is not well documented (not even mentioned) in their GCM implementation tutorial.