Push Notifications

Introduction

Sample App which registers with GCM and receives device token from it 

GCM Service Class

import android.app.Notification;

import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.util.Log;

import com.google.android.gcm.GCMBaseIntentService;

public class GCMIntentService extends GCMBaseIntentService {

    private static String TAG = GCMIntentService.class.getName();
    /**
     * Intent used to display a message in the screen.
     */
    public static final String DISPLAY_MESSAGE_ACTION = "com.google.android.gcm.demo.app.DISPLAY_MESSAGE";

    /**
     * Intent's extra that contains the message to be displayed.
     */
    public static final String EXTRA_MESSAGE = "message";

    public GCMIntentService() {
        super("project no");
    }

    @Override
    protected void onError(Context context, String errorId) {
        Log.i(TAG, "Received message " + errorId);
    }

    @Override
    protected void onMessage(Context context, Intent intent) {
        Log.i(TAG, "Received message");
        // String message = getString(R.string.gcm_message);
        String message = intent.getExtras().getString("message");
        displayMessage(context, message);
        // notifies user
        generateNotification(context, message);
    }

    @Override
    protected void onRegistered(Context context, String registrationId) {
        Log.i(TAG, "Device registered: regId = " + registrationId);
    }

    @Override
    protected void onUnregistered(Context context, String registrationId) {
        // TODO Auto-generated method stub

    }

    private void displayMessage(Context context, String message) {
        Intent intent = new Intent(DISPLAY_MESSAGE_ACTION);
        intent.putExtra(EXTRA_MESSAGE, message);
        context.sendBroadcast(intent);
    }

    /**
     * Issues a notification to inform the user that server has sent a message.
     */
    private static void generateNotification(Context context, String message) {

        int icon = R.drawable.ic_launcher;
        long when = System.currentTimeMillis();
        NotificationManager notificationManager = (NotificationManager)context.getSystemService(Context.NOTIFICATION_SERVICE);
        Notification notification = new Notification(icon, message, when);
        String title = context.getString(R.string.app_name);
        Intent notificationIntent = new Intent(context, TimerScreen.class);
        // set intent so it does not start a new activity
        notificationIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
        PendingIntent intent =PendingIntent.getActivity(context, 0, notificationIntent, 0);
        notification.setLatestEventInfo(context, title, message, intent);
        notification.flags |= Notification.FLAG_AUTO_CANCEL;
        notificationManager.notify(0, notification);

    }
}

BroadCast Receiver

package com.example.responsetest;

import android.app.Activity;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;

public class TimerScreen extends Activity {
    /**
     * Intent's extra that contains the message to be displayed.
     */
    public static final String EXTRA_MESSAGE = "message";

    private final BroadcastReceiver mHandleMessageReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String newMessage = intent.getExtras().getString(EXTRA_MESSAGE);
        }
    };

}

MainActivity

package com.example.responsetest;

import com.google.android.gcm.GCMRegistrar;


import android.os.Bundle;
import android.app.Activity;
import android.util.Log;
import android.view.Menu;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
       
        // Make sure the device has the proper dependencies.
                GCMRegistrar.checkDevice(this);

                // Automatically registers application on startup.
                GCMRegistrar.register(this, "projectno");

                final String regId = GCMRegistrar.getRegistrationId(this);
                Log.d("GCMIntentService", "GCMIntentService " + regId);
               
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

}

Client Jar

GCM Client jar is needed