A simple Android sample for using Google Cloud Messaging with upstream messaging
Java Groovy
Latest commit 92ef387 Jan 20, 2014 @writtmeyer Added a README.md file
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This is a sample project to showcase Google Cloud Messaging using upstream messaging. The project was originally created for a talk I held at the Dutch Android User Group meeting in Utrecht on January, 16th 2014. If you ever have the possibility to visit a meeting of the Dutch AUG, I stringly recommend to do so. It has been a gorgeous evening!

Libraries used

This demo makes of EventBus, Google Play Services, the Support Library, and ActionBarCompat. Thus you have to add those to your project:

dependencies {
    compile 'com.google.android.gms:play-services:4.0.30'
    compile 'com.android.support:appcompat-v7:+'
    compile 'com.android.support:support-v4:19.0.0'
    compile 'de.greenrobot:eventbus:2.2.0'
    compile 'de.keyboardsurfer.android.widget:crouton:1.8.2'

Most important classes

All important classes are within the com.grokkingandroid.sampleapp.samples.gcm package.

The initial starting acvtivity is GcmDemoActivity.java. Most logic though is contained in GcmDemoFragments.

The BroadcastRecevier GcmBroadcastReceiver just passes the intent through to the IntentService GcmIntentService which handles calls from Google's cloud. The GcmIntentService is also used by the GcmDemoFragment for all upstream calls.

Not all sources of the demo might have appropriate license annotation. Nevertheless: The license for the code used in this demo is the Apache Software License. You can find the license in the LICENSE-2.0.txt file at the root of the project.


To run this project you need a GCM-project number. You can read more about it on the Getting Started page of Google's documentation.

I suggest to put the project number into a separate resource file named gcm_strings.xml. This file is already excluded from the repository by the current .gitignore file.

Keep in mind: For using the newer features of Google Cloud Messaging (upstream messaging / user notifications) you need to apply first. See for example the note at the top of the http://developer.android.com/google/gcm/notifications.html. You can find a current link there as well.

Relevant Blogposts on Grokking Android

Right now I haven't finished the blog post about GCM. It's in the making and should be up pretty soon.

Warning: Generated codebase

Please note: I have created the core of this sample using a custom generator. I'm going to publish many samples when writing blog posts and want to keep my work for those as focused as possible. The generator helps me achieve this even if it means that some code might seem a bit odd. I always refer to the relevant classes at the beginning of the README file.

tl;dr: Do not copy without thinking - should go without saying, but it's better to mention it once more!

Developed by

Wolfram Rittmeyer - You can contact me via:


A big thanks to the organizers of the meetup in Utrecht. It was a great evening with good presentations and interesting conversations in the breaks!

Also thanks to all my readers and blog commenters. Your feedback helps me to stay on track and to go on with projects like this. Without my blog (and thus you) I probably woouln't have been invited in the first place :-)

Special thanks also to the Android crowd on G+. You're an awesome crowd. I have gained many insights by reading posts there, by following links to blog posts or by discussions on G+! And it was great to meet some of you in Utrecht.

And finally: This readme was created using dillinger.io. Thanks for this service.


Copyright 2014 Wolfram Rittmeyer

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at


Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
See the License for the specific language governing permissions and
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