GCM Demo

Hello All,

Android has replacing C2DM (Cloude to Device Messaging) service with GCM (Google Cloude Messaging). Recently Google introduced Google Drive which is based on Cloude computing and now GCM which shows future is Cloude computing. With this GCM your application can receive only from specified servers message that is the flow of c2dm and gcm are exactly same other than you can let google know from which server application will receive message. Also in c2dm we required a developers gmail id to register for c2dm now we don’t need gmail id to send for authentication but instead you need to create a project on Google which has a id which we will send as “sender id”.

I am providing you all the steps by following these you can implement GCM in your projects..
1) Goto https://code.google.com/apis/console and create a project same name as your application you will see the browser link has changed as https://code.google.com/apis/console/#project:4815162342 it contains your project id (4815162342 in this example) copy that we reuired that in your applciation as sender id.
2) In the main Google APIs Console page, select Services. Turn the Google Cloud Messaging toggle to ON. In the Terms of Service page, accept the terms.
3) In the main Google APIs Console page, select API Access. Now you can see there is API key if you use that key your application can receive messages from any server & if you want to restrict servers you can generate new server key using button there as “Create new server key…”. Once you clicked this button it will show you anthore view where you need to give server ip address from which you applciation will receive message.

Now you have sender id & api key so lets move to your application & lets make changes in to authenticate & receive message from server.

1) Copy the gcm.jar file from the SDK’s gcm-client/dist directory to your application classpath. As external jar.
2) now your manifest files will look like

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
 package="com.androidmyway.demo.gcmdemo"
 android:versionCode="1"
 android:versionName="1.0" >

<!-- GCM requires Android SDK version 2.2 (API level 8) or above. -->
 <!-- The targetSdkVersion is optional, but it's always a good practice
 to target higher versions. -->
 <uses-sdk
 android:minSdkVersion="8"
 android:targetSdkVersion="15" />

<!-- GCM connects to Google Services. -->
 <uses-permission android:name="android.permission.INTERNET" />
 <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
 <uses-permission android:name="android.permission.READ_PHONE_STATE" />

<!-- GCM requires a Google account. -->
 <uses-permission android:name="android.permission.GET_ACCOUNTS" />

<!-- Keeps the processor from sleeping when a message is received. -->
 <uses-permission android:name="android.permission.WAKE_LOCK" />

<!--
 Creates a custom permission so only this app can receive its messages.

NOTE: the permission *must* be called PACKAGE.permission.C2D_MESSAGE,
 where PACKAGE is the application's package name.
 -->
 <permission
 android:name="com.androidmyway.demo.gcmdemo.permission.C2D_MESSAGE"
 android:protectionLevel="signature" />
 <uses-permission
 android:name="com.androidmyway.demo.gcmdemo.permission.C2D_MESSAGE" />

<!-- This app has permission to register and receive data message. -->
 <uses-permission
 android:name="com.google.android.c2dm.permission.RECEIVE" />
 <!-- Keeps the device on vibrating mode when a message is received. -->
 <uses-permission android:name="android.permission.VIBRATE" />

 <application
 android:icon="@drawable/ic_launcher"
 android:label="@string/app_name"
 android:theme="@android:style/Theme.Black.NoTitleBar" >
 <activity
 android:name=".MainActivity"
 >
 <intent-filter>
 <action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />
 </intent-filter>
 </activity>

 <!--
 BroadcastReceiver that will receive intents from GCM
 services and handle them to the custom IntentService.

The com.google.android.c2dm.permission.SEND permission is necessary
 so only GCM services can send data messages for the app.
 -->
 <receiver
 android:name="com.google.android.gcm.GCMBroadcastReceiver"
 android:permission="com.google.android.c2dm.permission.SEND" >
 <intent-filter>
 <!-- Receives the actual messages. -->
 <action android:name="com.google.android.c2dm.intent.RECEIVE" />
 <!-- Receives the registration id. -->
 <action android:name="com.google.android.c2dm.intent.REGISTRATION" />
 <category android:name="com.androidmyway.demo.gcmdemo" />
 </intent-filter>
 </receiver>

 <!--
 Application-specific subclass of GCMBaseIntentService that will
 handle received messages.

By default, it must be named .GCMIntentService, unless the
 application uses a custom BroadcastReceiver that redefines its name.
 -->
 <service android:name=".GCMIntentService" />

 </application>

</manifest>

3) now you need to create GCMIntentService as follows

package com.androidmyway.demo.gcmdemo;

import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.os.PowerManager;
import android.os.PowerManager.WakeLock;
import android.util.Log;

import com.google.android.gcm.GCMBaseIntentService;

public class GCMIntentService extends GCMBaseIntentService{

public GCMIntentService(){
 super(Utils.GCMSenderId);
 }

@Override
 protected void onError(Context context, String regId) {
 // TODO Auto-generated method stub
 Log.e("", "error registration id : "+regId);
 }

@Override
 protected void onMessage(Context context, Intent intent) {
 // TODO Auto-generated method stub
 handleMessage(context, intent);
 }

@Override
 protected void onRegistered(Context context, String regId) {
 // TODO Auto-generated method stub
// Log.e("", "registration id : "+regId);
 handleRegistration(context, regId);
 }

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

 }

@SuppressWarnings({ "deprecation", "static-access" })
 private void handleMessage(Context context, Intent intent) {
 // TODO Auto-generated method stub
 Utils.notiMsg = intent.getStringExtra("msg");
 Utils.notiTitle = intent.getStringExtra("title");
 Utils.notiType = intent.getStringExtra("type");
 Utils.notiUrl = intent.getStringExtra("url");

 int icon = R.drawable.ic_launcher; // icon from resources
 CharSequence tickerText = Utils.notiTitle;//intent.getStringExtra("me"); // ticker-text

 long when = System.currentTimeMillis(); // notification time
 CharSequence contentTitle = ""+Utils.notiMsg; //intent.getStringExtra("me"); // message title

NotificationManager notificationManager =
 (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
 Notification notification = new Notification(icon, tickerText, when);
 Intent notificationIntent = new Intent(context, MainActivity.class);
 PendingIntent pendingIntent = PendingIntent.getActivity(context, 0, notificationIntent, 0);

notification.setLatestEventInfo(context, contentTitle, "", pendingIntent);
 notification.flags|=notification.FLAG_INSISTENT|notification.FLAG_AUTO_CANCEL;
 notification.defaults |= Notification.DEFAULT_SOUND|Notification.DEFAULT_LIGHTS;
 notification.vibrate=new long[] {100L, 100L, 200L, 500L};
 notificationManager.notify(1, notification);
 Utils.notificationReceived=true;
 PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
 WakeLock wl = pm.newWakeLock(PowerManager.FULL_WAKE_LOCK | PowerManager.ACQUIRE_CAUSES_WAKEUP, "TAG");
 wl.acquire();

 }

 private void handleRegistration(Context context, String regId) {
 // TODO Auto-generated method stub
 Utils.registrationId = regId;
 Log.e("", "registration id : "+regId);

 }
}

4) now I am creating a class which keeps all static variables I am using throughout the application which has sender id messge recived from server and also a special boolean varible which will tell our application that is there a notification recivied or not. Which will look like below.

package com.androidmyway.demo.gcmdemo;

import android.app.Application;

public class Utils extends Application{

public static String GCMSenderId = "Your sender ID";
 public static boolean notificationReceived;
 public static String notiTitle="",notiType="",notiMsg="",notiUrl="",registrationId = "";

}

5)Now your activity which will send “senderID” to server. Generally I register device in splash acitivity but as I am creating a demo so I have only one activity. You can write this code in activity which shows a splash screen to user or activity which comes after this splash activity. Code will be like this

package com.androidmyway.demo.gcmdemo;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.os.PowerManager;
import android.os.PowerManager.WakeLock;
import android.util.Log;

import com.google.android.gcm.GCMRegistrar;

public class MainActivity extends Activity {

@Override
 public void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 GCMRegistrar.checkDevice(this);

 // Make sure the device has the proper dependencies.
 GCMRegistrar.checkDevice(this);
 // Make sure the manifest was properly set - comment out this line
 // while developing the app, then uncomment it when it's ready.
 GCMRegistrar.checkManifest(this);

 final String regId = GCMRegistrar.getRegistrationId(this);

 if (regId.equals("")) {
 GCMRegistrar.register(this, Utils.GCMSenderId);
 } else {
 Log.v("", "Already registered: "+regId);
 }

 /**
 We set this varible true when we recive notification
 (this code must be in activity which not showing your applciaiton splash screen).
 */
 if (Utils.notificationReceived) {
 onNotification();
 }
 }

 @Override
 protected void onDestroy() {
 GCMRegistrar.onDestroy(this);
 super.onDestroy();
 }

 public void onNotification(){
 Utils.notificationReceived=false;
 PowerManager pm = (PowerManager) getSystemService(POWER_SERVICE);
 WakeLock wl = pm.newWakeLock(PowerManager.ACQUIRE_CAUSES_WAKEUP, "TAG");
 wl.acquire();

AlertDialog.Builder mAlert=new AlertDialog.Builder(this);
 mAlert.setCancelable(true);

mAlert.setTitle(Utils.notiTitle);
 mAlert.setMessage(Utils.notiMsg);
 mAlert.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
 public void onClick(DialogInterface dialog, int which) {
 // TODO Auto-generated method stub
 dialog.dismiss();
 }
 });
 mAlert.setNegativeButton("No", new DialogInterface.OnClickListener() {
 public void onClick(DialogInterface dialog, int which) {
 // TODO Auto-generated method stub
 dialog.dismiss();
 }
 });

 mAlert.show();
 }

}

You need to make changes in onNotification() method which will show alertbox.

Now your client sode is ready but still you required server side which will be like below. Now I am using curl functionality from php which is used to comunicate between http, shttp, etc… This code will required your device registration id, api key, message title, message body. this code will look like
Serverside code

<?php
 $url = 'https://android.googleapis.com/gcm/send';
 $serverApiKey = "Your Api key";
 $reg = "Device registration id";

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

 $data = array(
 'registration_ids' => array($reg)
 , 'data' => array(
 'type' => 'New'
 , 'title' => 'GCM'
 , 'msg' => 'Here we completed GCM demo.'
 , 'url' => 'https://androidmyway.wordpress.com'
 )
 );

 $ch = curl_init();
 curl_setopt($ch, CURLOPT_URL, $url);
 if ($headers)
 curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
 curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
 curl_setopt($ch, CURLOPT_POST, true);
 curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
 curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($data));

 $response = curl_exec($ch);

curl_close($ch);
 print ($response);

?>

Note:—
1) In above code you can see there is a data array which has few key value pairs you can customize them as you want currently they are just as I want.
If you get any error then you need to activate curl in php settings.
2) Here as we are required device resigstration id to which we need to send message you need to make changes in “handleRegistration” in “GCMIntentService” so that you can send device registation id to your server which will save them to send messages.
3) you can send messages to multiple devices just need to mentions all registration ids in a array seperated by comma.
If any help needed please let me know & if any process I written wrong please inform me.

For more help check  http://developer.android.com/guide/google/gcm/gs.html

Thank You

Added code on GitHub
https://github.com/sandipmjadhav/GCMDemo