GCM Client Android Library

A Google Cloud Messaging (GCM) client helper library for Android suitable for common use cases.

Implementing GCM Client

A full GCM implementation requires both implementations of a client and a server. The following sections only cover the steps involved in developing a GCM client.

Step 1: Obtaining an API Key

Follow this guide to create a Google API project, enable the GCM service, and get your sender ID and an API key if you have not done this already.

Step 2: Set Up Google Play Services

You must set up your project to use the Google Play Services SDK, as described in here and here.

Step 3: Check for Google Play Services Availability

As described in here, you should check the device for Google Play Services availbility before accessing Google Play Services features. This check should be done in two places: in the main activity's onCreate() and onResume() methods. For example:

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    
    ...
    
    if (GcmUtils.checkPlayServices()) {
        // If this check succeeds, proceed with normal processing.
        // Otherwise, the client library will automatically prompt
        // the user to install or upgrade Google Play Services.
    }
}

@Override
protected void onResume() {
    super.onResume();
    GcmUtils.checkPlayServices();
}

Step 4: Register for GCM

You app must register with GCM servers before it can receive message. When an app registers, it receives a registration ID, which should then be stored for future use.

To register with GCM, extend GcmRegistrar. In your main activity, call getRegistrationId() to see whether there is an existing registration ID stored in shared preferences.

If the registration ID does not exist, you should call registerInBackground() method to register. This takes place on a background thread.

After registering, onRegister() will be called. You should store the registration ID in a server-side application for future use.

Step 5: Receive messages

To receive GCM messages, extends GcmIntentService. When your app receives messages from GCM servers, onMessageReceived() method will be called with the message payload in the extras.

Step 6: Edit You Application's Manifest

You must edit your AndroidManifest.xml as described in here.

Here is an example manifest:

...
<application ...>
    <receiver
        android:name=".MyGcmBroadcastReceiver"
        android:permission="com.google.android.c2dm.permission.SEND">
        <intent-filter>
            <action android:name="com.google.android.c2dm.intent.RECEIVE" />
            <category android:name="com.example.gcm" />
        </intent-filter>
    </receiver>
    <service android:name=".MyGcmIntentService" />
</application>