How to add gcm messaging to your app

If you tried the gcm playground and it does not work then try gcm quickstart tutorial.

git clone https://github.com/googlesamples/google-services.git

You need to have a google developers account and created an sample empty project using the developers console.

Use the following link to get your configuration file google-services.json

For the package name use: gcm.play.android.samples.com.gcmquickstart

You need to store the Server API Key and Sender ID in a safe location.

Save the google-services.json file into the google-services/android/gcm directory.

cd google-services/android/gcm
./gradlew assemble

Use gradlew assemble to build app
If you use gradle and experience build errors then you might have an older version of gradle installed use instead the gradlew script to get the appropriate version.
gradlew might have problems locating the SDK location make sure to specify ANDROID_HOME
Install the apk located at app/build/outputs/apk

Modify the GcmSender.java file with the API_KEY from previously, file located at gcmsender\src\main\java\gcm\play\android\samples\com\gcmsender use gcmsender to send message

./gradlew run -Pmsg="<message>"
{"message_id":5323982615956046161}

Check your device/emulator for notification or logcat for confirmation of the receipt of the GCM message.

Adding gcm messaging to your app

• Add google dependencies to build.gradle

dependencies {
...
compile 'com.google.android.gms:play-services-gcm:8.4.0'
...
}
apply plugin: 'com.google.gms.google-services'

• Add services to AndroidManifest.xml

    <application
	...
        <receiver
            android:name="com.google.android.gms.gcm.GcmReceiver"
            android:exported="true"
            android:permission="com.google.android.c2dm.permission.SEND" >
            <intent-filter>
                <action android:name="com.google.android.c2dm.intent.RECEIVE" />
                <category android:name="com.mycompany.android.androidproject" />
            </intent-filter>
        </receiver>

        <service
            android:name="com.mycompany.android.androidproject.MyGcmListenerService"
            android:exported="false" >
            <intent-filter>
                <action android:name="com.google.android.c2dm.intent.RECEIVE" />
            </intent-filter>
        </service>
        <service
            android:name="com.mycompany.android.androidproject.MyInstanceIDListenerService"
            android:exported="false">
            <intent-filter>
                <action android:name="com.google.android.gms.iid.InstanceID"/>
            </intent-filter>
        </service>
        <service
            android:name="com.mycompany.android.androidproject.RegistrationIntentService"
            android:exported="false">
        </service>
	...
	</application>

• MainActivity initialize broadcast receiver, register broadcast receiver, check google play services, start register service
• Register Intent Service Register with gcm, obtain instanceid, Subscribe to topic
• GCM Listener Service implement onMessageReceived get message from Bundle, show notification