Android GCM basic implementation

Question

UPDATE: I fixed the problems in the code below so this makes a nice basic working example of how to use GCM

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So, I'm trying to implement Android GCM into my app. Here are the relevant parts I've added to the manifest:

<uses-sdk android:minSdkVersion="8" android:targetSdkVersion="20" />

<permission
    android:name=".permission.C2D_MESSAGE"
    android:protectionLevel="signature" />
<uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" />
<uses-permission android:name=".permission.C2D_MESSAGE" />
<uses-permission android:name="android.permission.WAKE_LOCK"/>
<uses-permission android:name="android.permission.GET_ACCOUNTS"/>

...

<receiver
    android:name="com.google.android.gcm.GCMBroadcastReceiver"
    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.badbob.app.gmctestapp" />
    </intent-filter>
</receiver>

<service android:name=".GCMIntentService" />

I've added the following code to the onCreate of my main activity:

    GCMRegistrar.checkDevice( this );
    GCMRegistrar.checkManifest( this );
    final String regId = GCMRegistrar.getRegistrationId( this );
    if( regId.equals( "" ) ) {
        GCMRegistrar.register( this, GCM_SENDER_ID );
    }
    else {
        Log.v( LOG_TAG, "Already registered" );
    }

I've also created the GCMIntenetService class like so:

public class GCMIntentService extends GCMBaseIntentService {

    private static final String LOG_TAG = "GetAClue::GCMIntentService";

    public GCMIntentService() {
        super( GCM_SENDER_ID );
        // TODO Auto-generated constructor stub
        Log.i( LOG_TAG, "GCMIntentService constructor called" );
    }

    @Override
    protected void onError( Context arg0, String errorId ) {
        // TODO Auto-generated method stub
        Log.i( LOG_TAG, "GCMIntentService onError called: " + errorId );
    }

    @Override
    protected void onMessage( Context arg0, Intent intent ) {
        // TODO Auto-generated method stub
        Log.i( LOG_TAG, "GCMIntentService onMessage called" );
        Log.i( LOG_TAG, "Message is: " + intent.getStringExtra( "message" ) );
    }

    @Override
    protected void onRegistered( Context arg0, String registrationId ) {
        // TODO Auto-generated method stub
        Log.i( LOG_TAG, "GCMIntentService onRegistered called" );
        Log.i( LOG_TAG, "Registration id is: " + registrationId );
    }

    @Override
    protected void onUnregistered( Context arg0, String registrationId ) {
        // TODO Auto-generated method stub
        Log.i( LOG_TAG, "GCMIntentService onUnregistered called" );
        Log.i( LOG_TAG, "Registration id is: " + registrationId );
    }
}

When I run this I get this in LogCat:

07-11 11:28:46.340: V/GCMRegistrar(27435): Registering receiver
07-11 11:28:46.370: D/GCMRegistrar(27435): resetting backoff for com.badbob.app.getacluebeta
07-11 11:28:46.380: V/GCMRegistrar(27435): Registering app com.badbob.app.getacluebeta of senders 128205395388

From what I've gleaned from other posts I should get a registration ID in LogCat but I"m not. Also onRegistered() in GCMIntentService never gets called. So what am I doing wrong?

Answer 1

this is incorrect

protected GCMIntentService( String senderId ) {          super(senderId);} 

As it states in the documentation. you must declare a PUBLIC, NO ARGUMENT constructor for GCMIntentService. Otherwise the GCMIntentService can't be instantiated properly by background intent services.

public GCMIntentService(){ super(senderID);} 

the senderID can be a hard coded constant string because it will no longer change with the new GCM. It's also very important you use the correct senderID. 24 hours is long enough for yours to be active so if my above solution doesn't work you are using the incorrect senderID. Everything else looks great.

The senderID is in the URL of your web browser when you are browsing the Google API access page. Click on GCM and a 12 digit number will be present in the browser URL. That is the correct key to use. NOT your API key. That is used on the App server side.

Answer 2

I also had this ANNOYing bug, til now. The Problem was, that i declared the intentservice inside another package... even if i declared the name in the android manifest and no classnotfound exception had been place... no error at all could be found... so i made sure the intentservice is in the root package.

Answer 3

I think you have some issues in the code.

You should do the registration of your own broadcast receiver in the manifest file and that receiver will trigger the <service android:name=".GCMIntentService" />.

Therefore you must do something like I write below.

• The receiver must be declared like:

  <receiver
      android:name="your.package.name.YourBroadCastReceiver"
      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" />
      </intent-filter>
  

• Your broadcast receiver that will start the service.

  public class YourBroadCastReceiver extends BroadcastReceiver {
  
  @Override
   public final void onReceive(Context context, Intent intent) {
       GCMIntentService .runIntentInService(context, intent);
       setResult(Activity.RESULT_OK, null, null);
   }  
  }
  

I advice you to take a look at the official GCM documentation where you can find a good example.

And... don't forget to enable the Google Cloud Messaging service in the main Google APIs Console page.

Let me know if it helps!