Google Cloud Messaging (Android 消息推送技术) （二）
（一） 在上一章，我们提到Android 消息推送的基本流程和需要的几个键值。
这里介绍一下怎样使用Google Cloud Messaging （GCM）。
对于GCM的实现，google 早期使用的接口可以参考这篇文章。文章中已经充分介绍了在老接口下怎样实现GCM。
http://blog.csdn.net/huangjialiang1986/article/details/8056221
下面是对这篇文章代码的部分更改：
Android 客户端的代码为：
https://github.com/yuxiaohui78/Google_Cloud_Messaging/tree/master/GCMClientOnMobile_deprecated_version
模拟第三方服务器的消息发送部分代码：
https://github.com/yuxiaohui78/Google_Cloud_Messaging/tree/master/GCMSendOnPC
（二）由于google已经决定废弃老接口。所以下面我们来介绍一下新接口怎样实现。
新的Api接口需要google service 3.1+ 的支持。
1.在AndroidManifest.xml 中增加支持，允许接收云消息com.google.android.c2dm.permission.RECEIVE
<manifest package="com.example.gcm" ...>
<uses-sdk android:minSdkVersion="8" android:targetSdkVersion="17"/>
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.GET_ACCOUNTS" />
<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" />
<permission android:name="com.example.gcm.permission.C2D_MESSAGE"
android:protectionLevel="signature" />
<uses-permission android:name="com.example.gcm.permission.C2D_MESSAGE" />
<application ...>
<receiver
android:name=".GcmBroadcastReceiver"
android:permission="com.google.android.c2dm.permission.SEND" >
<intent-filter>
<action android:name="com.google.android.c2dm.intent.RECEIVE" />
<category android:name="com.example.gcm" />
</intent-filter>
</receiver>
<service android:name=".GcmIntentService" />
</application>
</manifest>
2.注册设备
/**
* Main UI for the demo app.
*/
public class DemoActivity extends Activity {
public static final String EXTRA_MESSAGE = "message";
public static final String PROPERTY_REG_ID = "registration_id";
private static final String PROPERTY_APP_VERSION = "appVersion";
private final static int PLAY_SERVICES_RESOLUTION_REQUEST = 9000;
/**
* Substitute you own sender ID here. This is the project number you got
* from the API Console, as described in "Getting Started."
*/
String SENDER_ID = "Your-Sender-ID";
/**
* Tag used on log messages.
*/
static final String TAG = "GCMDemo";
TextView mDisplay;
GoogleCloudMessaging gcm;
AtomicInteger msgId = new AtomicInteger();
SharedPreferences prefs;
Context context;
String regid;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mDisplay = (TextView) findViewById(R.id.display);
context = getApplicationContext();
// Check device for Play Services APK. If check succeeds, proceed with
// GCM registration.
if (checkPlayServices()) {
gcm = GoogleCloudMessaging.getInstance(this);
regid = getRegistrationId(context);
if (regid.isEmpty()) {
registerInBackground();
}
} else {
Log.i(TAG, "No valid Google Play Services APK found.");
}
}
...
}
3.进行异步注册
/**
* Registers the application with GCM servers asynchronously.
* <p>
* Stores the registration ID and app versionCode in the application's
* shared preferences.
*/
private void registerInBackground() {
new AsyncTask() {
@Override
protected String doInBackground(Void... params) {
String msg = "";
try {
if (gcm == null) {
gcm = GoogleCloudMessaging.getInstance(context);
}
regid = gcm.register(SENDER_ID);
msg = "Device registered, registration ID=" + regid;
// You should send the registration ID to your server over HTTP,
// so it can use GCM/HTTP or CCS to send messages to your app.
// The request to your server should be authenticated if your app
// is using accounts.
sendRegistrationIdToBackend();
// For this demo: we don't need to send it because the device
// will send upstream messages to a server that echo back the
// message using the 'from' address in the message.
// Persist the regID - no need to register again.
storeRegistrationId(context, regid);
} catch (IOException ex) {
msg = "Error :" + ex.getMessage();
// If there is an error, don't just keep trying to register.
// Require the user to click a button again, or perform
// exponential back-off.
}
return msg;
}
@Override
protected void onPostExecute(String msg) {
mDisplay.append(msg + "\n");
}
}.execute(null, null, null);
...
}
4.接收消息
public class GcmIntentService extends IntentService {
public static final int NOTIFICATION_ID = 1;
private NotificationManager mNotificationManager;
NotificationCompat.Builder builder;
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)) {
// 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(5000);
} catch (InterruptedException e) {
}
}
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.
private void sendNotification(String msg) {
mNotificationManager = (NotificationManager)
this.getSystemService(Context.NOTIFICATION_SERVICE);
PendingIntent contentIntent = PendingIntent.getActivity(this, 0,
new Intent(this, DemoActivity.class), 0);
NotificationCompat.Builder mBuilder =
new NotificationCompat.Builder(this)
.setSmallIcon(R.drawable.ic_stat_gcm)
.setContentTitle("GCM Notification")
.setStyle(new NotificationCompat.BigTextStyle()
.bigText(msg))
.setContentText(msg);
mBuilder.setContentIntent(contentIntent);
mNotificationManager.notify(NOTIFICATION_ID, mBuilder.build());
}
}
可用的代码：
https://github.com/yuxiaohui78/Google_Cloud_Messaging/tree/master/GCMClientOnMobile
使用代码的方法很简单，只需要将DemoActivity.java中的SENDER_ID替换为上一章中的Project Number就可以使用。
下一章，将介绍怎样测试Google Cloud Messaging。
http://developer.android.com/google/gcm/client.html
原始代码：
https://code.google.com/p/gcm/source/checkout