title: unable to interpret message from GCM
body: <p>I'm trying to understand how GCM works. To do so, I copy/paste the code that <a href="http://developer.android.com/" rel="nofollow">http://developer.android.com/</a> proposes in the section "implementing a GCM client".</p>
  
  <p>I don't have a server for now, so it's just a http request that I send from eclipse.</p>
  
  <p>Here is the request:</p>
  
  <pre><code>HttpEntity entity = new ByteArrayEntity(contenu.getBytes("UTF-8"));
      HttpClient client = new DefaultHttpClient();
      HttpPost post = new HttpPost(this.getAdresse());
      post.addHeader("Authorization", "key=AIzaSyANnvuPYJaSIDM7gorqdKh25uvpNA-4rvk");
      post.addHeader("Content-Type", "application/json");
      post.setEntity(entity);
  
      HttpResponse response = client.execute(post);
  </code></pre>
  
  <p>where "contenu" is this String: </p>
  
  <pre><code>{ "data": {
  "message":"hello"
    },
    "registration_ids": ["4", "8", "15", "16", "23", "42"]
  }
  </code></pre>
  
  <p>On my client app, I have this IntentService (found on the developers site):</p>
  
  <pre><code>package com.test.testnotification3;
  
   import com.google.android.gms.gcm.GoogleCloudMessaging;
  import com.test.testnotification3.R;
  
  import core.GcmBroadcastReceiver;
  import android.app.IntentService;
  import android.app.NotificationManager;
  import android.app.PendingIntent;
  import android.content.Context;
  import android.content.Intent;
  import android.os.Bundle;
  import android.os.SystemClock;
  import android.support.v4.app.NotificationCompat;
  import android.util.Log;
  
  public class GcmIntentService extends IntentService {
  public static final int NOTIFICATION_ID = 1;
  private NotificationManager mNotificationManager;
  NotificationCompat.Builder builder;
  static final String TAG = "GCMDemo";
  
  public GcmIntentService() {
      super("GcmIntentService");
  }
  
  @Override
  protected void onHandleIntent(Intent intent) {
      Bundle extras = intent.getExtras();
      GoogleCloudMessaging gcm = GoogleCloudMessaging.getInstance(this);
  
      // The getMessageType() intent parameter must be the intent you received
      // in your BroadcastReceiver.
      String messageType = gcm.getMessageType(intent);
  
  
  
      if (!extras.isEmpty()) {  // has effect of unparcelling Bundle
          /*
           * Filter messages based on message type. Since it is likely that GCM
           * will be extended in the future with new message types, just ignore
           * any message types you're not interested in, or that you don't
           * recognize.
           */
          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)) {
  
  
  
              Log.i(TAG, "Completed work @ " + SystemClock.elapsedRealtime());
              // Post notification of received message.
              sendNotification("Received: " + extras.toString());
              Log.i(TAG, "Received: " + extras.toString());
          }
      }
      // 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.
  public void sendNotification(String msg) {
      mNotificationManager = (NotificationManager)
              this.getSystemService(Context.NOTIFICATION_SERVICE);
  
      PendingIntent contentIntent = PendingIntent.getActivity(this, 0,
              new Intent(this, MainActivity.class), 0);
      long[] pattern = {0,1000};
  
      NotificationCompat.Builder mBuilder =
              new NotificationCompat.Builder(this)
      .setSmallIcon(R.drawable.ic_launcher)
      .setContentTitle("Coucou Matthieu")
      .setStyle(new NotificationCompat.BigTextStyle()
      .bigText(msg))
      .setContentText(msg)
      .setVibrate(pattern);
  
      mBuilder.setContentIntent(contentIntent);
      mNotificationManager.notify(NOTIFICATION_ID, mBuilder.build());
      }
  }
  </code></pre>
  
  <p>And I got this message in my Logcat:</p>
  
  <pre><code>07-06 19:26:15.627: I/GCMDemo(5095): Received: Bundle[{msg=hello,     android.support.content.wakelockid=1, collapse_key=do_not_collapse, from=472226063168}]
  </code></pre>
  
  <p>So my question is: how can I get just the "msg" field ?</p>
  
  <p>Thank you for your answer(s)!</p>