GCM Server

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In this document

  1. Requirements
  2. Setting Up GCM
  3. Setting Up an HTTP Server
    1. Using a standard web server
    2. Using App Engine for Java

See Also

  1. Getting Started
  2. GCM Client
  3. Cloud Connection Server

This document gives examples of GCM server-side code for HTTP. For an example of an XMPP server (Cloud Connection Server), see Getting Started. Note that a full GCM implementation requires a client-side implementation, in addition to the server. For a complete working example that includes client and server-side code, see Getting Started.

Requirements

For the web server:

  • Ant 1.8 (it might work with earlier versions, but it's not guaranteed).
  • One of the following:
  • A Google account registered to use GCM.
  • The API key for that account.

For the Android application:

  • Emulator (or device) running Android 2.2 with Google APIs.
  • The Google API project number of the account registered to use GCM.

Setting Up GCM

Before proceeding with the server and client setup, it's necessary to register a Google account with the Google API Console, enable Google Cloud Messaging in GCM, and obtain an API key from the Google API Console.

For instructions on how to set up GCM, see Getting Started.

Setting Up an HTTP Server

This section describes the different options for setting up an HTTP server.

Using a standard web server

To set up the server using a standard, servlet-compliant web server:

  1. From the open source site, download the following directories: gcm-server, samples/gcm-demo-server, and samples/gcm-demo-appengine.

  2. In a text editor, edit the samples/gcm-demo-server/WebContent/WEB-INF/classes/api.key and replace the existing text with the API key obtained above.
  3. In a shell window, go to the samples/gcm-demo-server directory.
  4. Generate the server's WAR file by running ant war:
    5. $ ant war

Buildfile:build.xml

init:
   [mkdir] Created dir: build/classes
   [mkdir] Created dir: dist

compile:
   [javac] Compiling 6 source files to build/classes

war:
     [war] Building war: dist/gcm-demo.war

BUILD SUCCESSFUL
Total time: 0 seconds
  5. Deploy the dist/gcm-demo.war to your running server. For instance, if you're using Jetty, copy gcm-demo.war to the webapps directory of the Jetty installation.
  6. Open the server's main page in a browser. The URL depends on the server you're using and your machine's IP address, but it will be something like http://192.168.1.10:8080/gcm-demo/home, where gcm-demo is the application context and /home is the path of the main servlet.

Note: You can get the IP by running ifconfig on Linux or MacOS, or ipconfig on Windows.

You server is now ready.

Using App Engine for Java

To set up the server using a standard App Engine for Java:

  1. Get the files from the open source site, as described above.

  2. In a text editor, edit samples/gcm-demo-appengine/src/com/google/android/gcm/demo/server/ApiKeyInitializer.java and replace the existing text with the API key obtained above.

    Note: The API key value set in that class will be used just once to create a persistent entity on App Engine. If you deploy the application, you can use App Engine's Datastore Viewer to change it later.

  3. In a shell window, go to the samples/gcm-demo-appengine directory.
  4. Start the development App Engine server by ant runserver, using the -Dsdk.dir to indicate the location of the App Engine SDK and -Dserver.host to set your server's hostname or IP address:
    5. $ ant -Dsdk.dir=/opt/google/appengine-java-sdk runserver -Dserver.host=192.168.1.10
Buildfile: gcm-demo-appengine/build.xml

init:
    [mkdir] Created dir: gcm-demo-appengine/dist

copyjars:

compile:

datanucleusenhance:
  [enhance] DataNucleus Enhancer (version 1.1.4) : Enhancement of classes
  [enhance] DataNucleus Enhancer completed with success for 0 classes. Timings : input=28 ms, enhance=0 ms, total=28 ms. Consult the log for full details
  [enhance] DataNucleus Enhancer completed and no classes were enhanced. Consult the log for full details

runserver:
     [java] Jun 15, 2012 8:46:06 PM com.google.apphosting.utils.jetty.JettyLogger info
     [java] INFO: Logging to JettyLogger(null) via com.google.apphosting.utils.jetty.JettyLogger
     [java] Jun 15, 2012 8:46:06 PM com.google.apphosting.utils.config.AppEngineWebXmlReader readAppEngineWebXml
     [java] INFO: Successfully processed gcm-demo-appengine/WebContent/WEB-INF/appengine-web.xml
     [java] Jun 15, 2012 8:46:06 PM com.google.apphosting.utils.config.AbstractConfigXmlReader readConfigXml
     [java] INFO: Successfully processed gcm-demo-appengine/WebContent/WEB-INF/web.xml
     [java] Jun 15, 2012 8:46:09 PM com.google.android.gcm.demo.server.ApiKeyInitializer contextInitialized
     [java] SEVERE: Created fake key. Please go to App Engine admin console, change its value to your API Key (the entity type is 'Settings' and its field to be changed is 'ApiKey'), then restart the server!
     [java] Jun 15, 2012 8:46:09 PM com.google.appengine.tools.development.DevAppServerImpl start
     [java] INFO: The server is running at http://192.168.1.10:8080/
     [java] Jun 15, 2012 8:46:09 PM com.google.appengine.tools.development.DevAppServerImpl start
     [java] INFO: The admin console is running at http://192.168.1.10:8080/_ah/admin
  5. Open the server's main page in a browser. The URL depends on the server you're using and your machine's IP address, but it will be something like http://192.168.1.10:8080/home, where /home is the path of the main servlet.

    6. Note: You can get the IP by running ifconfig on Linux or MacOS, or ipconfig on Windows.

You server is now ready.