Getting Started with Android Push Notification : Latest Google Cloud Messaging (GCM) - step by step complete tutorial

GCM is a free service that helps developers send data from servers to their Android applications on Android devices, and upstream messages from the user's device back to the cloud.

1. Create/Register App on Google Cloud

2. Setup Cloud SDK with Development

3. Configure project for GCM

4. Get Device Registration ID

5. Send Push Notifications

6. Receive Push Notifications

7. Handle Further step as per Notification type. 

1. Create and Register Application on Google Cloud

Go to the Google Cloud Console -  https://cloud.google.com/console

Login with your gmail account

# Create New Project

Create New Project

Complet the Mobile number verification for security

# Get SENDER_ID

Once you create Project, you will get landed on google cloud’s dash board

Here you can see SENDER_ID

Note : please note down SENDER_ID it is important to get RegID from GCM

# Enable Google cloud messaging service

From Dashboard go to —> APIs & auth

Switch ON - Google Cloud Messaging for Android option

# Get API key

select API & auth  —> Registered apps

click Register App button

Give the details this way

If you are Sending Push Notification From your Local Web Server

Name - MyCloud App

Platform -  [ Android   : Accessing APIs via a web server ]

Click Register.

If you are Sending Push Notification From your Android App itself

Name - MyCloud App

Platform -  [ Android   : Accessing APIs directly from Android ]

Package Name -

SHA1 fingerprint -

Check here How to Generate SHA key for your app

https://developers.google.com/console/help/new/

Hint : Just search for the string “To find your SHA-1 fingerprint:" and follow the instructions

Click Register.

Once it get registered —> click on Server Key  —> copy API key

Note : please note down API_KEY , it is important for sending PN Message to GCM

Done!!

2. Setup Cloud SDK with Development

Google Cloud Messaging require Google Play Service SDK installed in our Development

# Install Google Play Service SDK

Go to Android SDK manager —> Extras 

Install Google Play Service SDK

Install Google Play Service for Froyo SDK (If your app supports android 2.2)

# Update Android Support Library

Go to Android SDK manager —> Extras

Install or Update Android Support Library 

# Import Google Play Service SDK into our Project

Go to path where Android SDK is installed in your system

copy the library project named “google-play-services_lib” from location

/extras/google/google_play_servies/libproject

and paste where you maintain your lib projects

Now come to project —> Import —>Android —> Existing Android code in Workspace

# Add Google Play Service Lib to build path

Right click on project —> Build Path —> Configure Build Path

Click on Android —> Is Library —> Add —>Apply.

Done!!

3. Configure project for GCM 

# Update AndroidManifest file

For enable GCM in our project we need to add few permission in our manifest file

Go to AndroidManifest.xml and add below code

# Add Permission

<uses-permission android:name="android.permission.INTERNET”/>

<uses-permission android:name="android.permission.GET_ACCOUNTS" />
<uses-permission android:name="android.permission.WAKE_LOCK" />

<uses-permission android:name="android.permission.VIBRATE" />

<uses-permission android:name=“.permission.RECEIVE" />

<uses-permission android:name=“<your_package_name_here>.permission.C2D_MESSAGE" />

<permission android:name=“<your_package_name_here>.permission.C2D_MESSAGE"

        android:protectionLevel="signature" />

# Add GCM Broadcast Receiver declaration

add GCM Broadcast Receiver declaration in your application tag

<application

        <receiver
            android:name=".GcmBroadcastReceiver"

            android:permission="com.google.android.c2dm.permission.SEND" ]]>
            <intent-filter]]>
                <action android:name="com.google.android.c2dm.intent.RECEIVE" />
                <category android:name="" />

            </intent-filter]]>

        </receiver]]>

     

<application/>

# Add GCM Servie declaration

<application

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

<application/>

# Update Proguard Config File

If you are using Proguard in your application then you must configure 

Go to proguard-project.txt File and add below code

———————————————————————

-keep class * extends java.util.ListResourceBundle {

    protected Object[][] getContents();
}

-keep public class com.google.android.gms.common.internal.safeparcel.SafeParcelable {
    public static final *** NULL;
}

-keepnames @com.google.android.gms.common.annotation.KeepName class *
-keepclassmembernames class * {
    @ccom.google.android.gms.common.annotation.KeepName *;
}

-keepnames class * implements android.os.Parcelable {
    public static final ** CREATOR;
}

———————————————————————

4. Get Device Registration ID

Now When device launch the app we need to Get the Registration ID to Send Message

So Go to your Launch/Splash Activity 

#Add Constants and Class Variables

private final static int PLAY_SERVICES_RESOLUTION_REQUEST = 9000;public static final String EXTRA_MESSAGE = "message";public static final String PROPERTY_REG_ID = "registration_id";private static final String PROPERTY_APP_VERSION = "appVersion";private final static String TAG = "LaunchActivity";
    protected String SENDER_ID = "your_sender_id";private GoogleCloudMessaging gcm =null;private String regid = null;

private Context context= null;

# Update OnCreate and OnResume methods

@Override
protected void onCreate(Bundle savedInstanceState)
{

     super.onCreate(savedInstanceState);

     setContentView(R.layout.activity_launch);

     context = getApplicationContext();

         if (checkPlayServices()) 

     {
            gcm = GoogleCloudMessaging.getInstance(this);
            regid = getRegistrationId(context);

            if (regid.isEmpty())
            {
                registerInBackground();
            }
            else
            {
            Log.d(TAG, "No valid Google Play Services APK found.");
            }
      }

 }

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

}

# Implement GCM Required methods (Add below methods in LaunchActivity)

private boolean checkPlayServices() {
        int resultCode = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);
        if (resultCode != ConnectionResult.SUCCESS) {
            if (GooglePlayServicesUtil.isUserRecoverableError(resultCode)) {
                GooglePlayServicesUtil.getErrorDialog(resultCode, this,
                        PLAY_SERVICES_RESOLUTION_REQUEST).show();
            } else {
                Log.d(TAG, "This device is not supported - Google Play Services.");
                finish();
            }
            return false;
        }
        return true;

 }

private String getRegistrationId(Context context) 

{
   final SharedPreferences prefs = getGCMPreferences(context);
   String registrationId = prefs.getString(PROPERTY_REG_ID, "");
   if (registrationId.isEmpty()) {
       Log.d(TAG, "Registration ID not found.");
       return "";
   }
   int registeredVersion = prefs.getInt(PROPERTY_APP_VERSION, Integer.MIN_VALUE);
   int currentVersion = getAppVersion(context);
   if (registeredVersion != currentVersion) {
        Log.d(TAG, "App version changed.");
        return "";
    }
    return registrationId;

}

private SharedPreferences getGCMPreferences(Context context) 

{
    return getSharedPreferences(LaunchActivity.class.getSimpleName(),
                Context.MODE_PRIVATE);

}

private static int getAppVersion(Context context) 

{
     try 

     {
         PackageInfo packageInfo = context.getPackageManager()
                    .getPackageInfo(context.getPackageName(), 0);
            return packageInfo.versionCode;
      } 

      catch (NameNotFoundException e) 

      {
            throw new RuntimeException("Could not get package name: " + e);
      }

}

private void registerInBackground() 

{     new AsyncTask() {
     Override
     protected Object doInBackground(Object... params) 

     {
          String msg = "";
          try 

          {
               if (gcm == null) 

               {
                        gcm = GoogleCloudMessaging.getInstance(context);
               }
               regid = gcm.register(SENDER_ID);               Log.d(TAG, "########################################");
               Log.d(TAG, "Current Device's Registration ID is: "+msg);     
          } 

          catch (IOException ex) 

          {
              msg = "Error :" + ex.getMessage();
          }

          return null;
     }     protected void onPostExecute(Object result) 

     { //to do here };

  }.execute(null, null, null);

}

Note : please store REGISTRATION_KEY, it is important for sending PN Message to GCM

also keep in mine this will be unique for all device, by using this only GCM will send Push Notification.

5. Send Push Notifications

# If you are sending message from your local web server

While launching/login app you need to send REGISTRATION_ID to your web server.

Actually Web server needs below three variable to send Message to GCM

REGISTRATION ID

API Key

Message Text

# If you are sending message from your Android app itself 

here you need to add below code in your activity to send Message 

public void onClick(final View view) 

{
     new AsyncTask() {     @Override
     protected String doInBackground(Void... params) 

     {
          String msg = "";          try {
               Bundle data = new Bundle();
               data.putString("my_message", "Hello World");
               data.putString("my_action",
               "com.google.android.gcm.demo.app.ECHO_NOW");
               String id = Integer.toString(msgId.incrementAndGet());               gcm.send(SENDER_ID + "@gcm.googleapis.com", id, data);
               msg = "Sent message";
           } catch (IOException ex) {
                 msg = "Error :" + ex.getMessage();
           }
           return msg;
     }     @Override
     protected void onPostExecute(String msg) {
          mDisplay.append(msg + "\n");
     }
  }.execute(null, null, null);

}

6. Receive Push Notifications

#Add GCM Broadcast Receiver Class

As we have already declared “GcmBroadcastReceiver.java” in our Manifest file, So lets create this class

update receiver class code this way

public class GcmBroadcastReceiver extends WakefulBroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) 

    {        ComponentName comp = new ComponentName(context.getPackageName(),
                GcmIntentService.class.getName());        startWakefulService(context, (intent.setComponent(comp)));
        setResultCode(Activity.RESULT_OK);
        Toast.makeText(context, “wow!! received new push notification", Toast.LENGTH_LONG).show();
    }

}

#Add GCM Service Class

As we have already declared “GcmBroadcastReceiver.java” in our Manifest file, So lets create this class

update receiver class code this way

public class GcmIntentService extends IntentService
{     public static final int NOTIFICATION_ID = 1;     private NotificationManager mNotificationManager;     private final static String TAG = "GcmIntentService";     public GcmIntentService() {
     super("GcmIntentService");     

     }     @Override
     protected void onHandleIntent(Intent intent) {
          Bundle extras = intent.getExtras();
          Log.d(TAG, "Notification Data Json :" + extras.getString("message"));

          GoogleCloudMessaging gcm = GoogleCloudMessaging.getInstance(this);
          String messageType = gcm.getMessageType(intent);          if (!extras.isEmpty()) {          if (GoogleCloudMessaging.MESSAGE_TYPE_SEND_ERROR
               .equals(messageType)) {
               sendNotification("Send error: " + extras.toString());
          } else if (GoogleCloudMessaging.MESSAGE_TYPE_DELETED
          .equals(messageType)) {
          sendNotification("Deleted messages on server: "
          + extras.toString());          // If it's a regular GCM message, do some work.
          } else if (GoogleCloudMessaging.MESSAGE_TYPE_MESSAGE
          .equals(messageType)) {

          // This loop represents the service doing some work.
          for (int i = 0; i < 5; i++) {
               Log.d(TAG," Working... " + (i + 1) + "/5 @ "

               + SystemClock.elapsedRealtime());               try {
                    Thread.sleep(5000);
               } catch (InterruptedException e) {
               }
             }
             Log.i(TAG, "Completed work @ " + SystemClock.elapsedRealtime());
             sendNotification(extras.getString("message"));
           }
        }        // Release the wake lock provided by the WakefulBroadcastReceiver.
        GcmBroadcastReceiver.completeWakefulIntent(intent);
     }     // Put the message into a notification and post it.
     // This is just one simple example of what you might choose to do with
     // a GCM message.
     private void sendNotification(String msg) {          mNotificationManager = (NotificationManager) this
          .getSystemService(Context.NOTIFICATION_SERVICE);
          PendingIntent contentIntent = PendingIntent.getActivity(this, 0,          new Intent(this, LaunchActivity.class), 0);

          NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(          this)
          .setSmallIcon(R.drawable.icon)
          .setContentTitle("Ocutag Snap")
          .setStyle(new NotificationCompat.BigTextStyle().bigText(msg))
          .setContentText(msg)
          .setDefaults(Notification.DEFAULT_SOUND | Notification.DEFAULT_VIBRATE);

          mBuilder.setContentIntent(contentIntent);          mNotificationManager.notify(NOTIFICATION_ID, mBuilder.build());
     }

}

That’s It We have Done!! no more coding. Just Build the App

If you sending Message from your own Web server tell them to send Message

or else you can send message from your own device.

Run the app. And you should Receive the Push Notification on Your Device with Sound + Vibration alert.

Cheers!! We Did It.

For more info please! Check below references : 

Google Documentation

http://developer.android.com/google/gcm/gs.html

http://developer.android.com/google/gcm/client.html

Google Open Source Code

http://code.google.com/p/gcm/source/checkout