public class GcmIntentService extends IntentService {
  public static int openintent;
  public static final int NOTIFICATION_ID = 1;
  private static final String TAG ="GcmIntentService";

  private static String number_in_your_service="somethingneversend";
  NotificationCompat.Builder builder;

  public GcmIntentService() {
    super("GcmIntentService");
  }

  @Override
  protected void onHandleIntent(Intent intent) {
    Bundle extras = intent.getExtras();
    GoogleCloudMessaging gcm = GoogleCloudMessaging.getInstance(this);
    String messageType = gcm.getMessageType(intent);

    if (!extras.isEmpty()) { // has effect of unparcelling Bundle
      if (GoogleCloudMessaging.MESSAGE_TYPE_SEND_ERROR.equals(messageType)) {
      } else if (GoogleCloudMessaging.MESSAGE_TYPE_DELETED.equals(messageType)) {
        // 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.i(TAG,"Working..." + (i + 1) +"/5 @" + SystemClock.elapsedRealtime());
          try {
            Thread.sleep(100);
          } catch (InterruptedException e) {
          }
        }
        Log.i(TAG,"Completed work @" + SystemClock.elapsedRealtime());
        // Post notification of received message.
        sendNotification(extras);
        Log.i(TAG,"Received:" + extras.toString());
      }
    }
    // Release the wake lock provided by the WakefulBroadcastReceiver.
    GcmBroadcastReceiver.completeWakefulIntent(intent);
  }

  private void sendNotification(Bundle extras) {

    if((extras.getString("server_number")).equals(number_in_your_service)) {

      Intent intent = new Intent(this, Main_Page_G.class);
      intent.putExtra("frame",100);
      intent.putExtra("bundle",extras);
      final PendingIntent contentIntent = PendingIntent.getActivity(this,
            120, intent, PendingIntent.FLAG_UPDATE_CURRENT);
      NotificationManager mNotificationManager;
      NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(
            GcmIntentService.this).setContentTitle("name")
            .setContentText("content")
            .setDefaults(Notification.DEFAULT_SOUND)
            .setContentInfo("Test")
            .setSmallIcon(R.drawable.rehablogo2)
            .setAutoCancel(true);
      mBuilder.setContentIntent(contentIntent);
      mNotificationManager = (NotificationManager) GcmIntentService.this
            .getSystemService(Context.NOTIFICATION_SERVICE);
      mNotificationManager.notify(id, mBuilder.build());
      id=Integer.parseInt(extras.getString("id"));
    }
  }
}

<?php
//Define your GCM server key here
define('API_ACCESS_KEY', 'your server api key');

//Function to send push notification to all
function sendToAll($message)
{
    $db = new DbOperation();
    $tokens = $db->getAllToken();
    $regTokens = array();
    while($row = $tokens->fetch_assoc()){
        array_push($regTokens,$row['token']);
    }
    sendNotification($regTokens,$message);
}


//function to send push notification to an individual
function sendToOne($email,$message){
    $db = new DbOperation();
    $token = $db->getIndividualToken($email);
    sendNotification(array($token),$message);
}


//This function will actually send the notification
function sendNotification($registrationIds, $message)
{
    $msg = array
    (
        'message' => $message,
        'title' => 'Android Push Notification using Google Cloud Messaging',
        'subtitle' => 'www.simplifiedcoding.net',
        'tickerText' => 'Ticker text here...Ticker text here...Ticker text here',
        'vibrate' => 1,
        'sound' => 1,
        'largeIcon' => 'large_icon',
        'smallIcon' => 'small_icon'
    );

    $fields = array
    (
        'registration_ids' => $registrationIds,
        'data' => $msg
    );

    $headers = array
    (
        'Authorization: key=' . API_ACCESS_KEY,
        'Content-Type: application/json'
    );

    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, 'https://android.googleapis.com/gcm/send');
    curl_setopt($ch, CURLOPT_POST, true);
    curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
    curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($fields));
    $result = curl_exec($ch);
    curl_close($ch);

    $res = json_decode($result);

    $flag = $res->success;
    if($flag >= 1){
        header('Location: index.php?success');
    }else{
        header('Location: index.php?failure');
    }
}