截至2016年5月18日，Firebase是谷歌为移动开发者提供的统一平台，包括推送通知。

恐怕你已经找到了两种可能的方法。谷歌是，至少在最初，要实现一个GChat api，你可以使用一个推/拉实现。不幸的是，这个库被Android 1.0砍掉了。

还是……

3)与服务器保持连接，每隔几分钟发送Keep -alive，服务器可以即时推送消息。这就是Gmail，谷歌Talk等的工作原理。

这里我写了几个步骤如何获得RegID和通知从头开始

在谷歌云上创建/注册应用程序 使用开发安装云SDK 为GCM配置项目 获取设备注册ID 发送推送通知 接收推送通知

你可以在下面的URL链接中找到完整的教程

Android推送通知入门:最新的谷歌云 消息传递(GCM) -一步一步完整的教程

代码片段获取注册ID(推送通知的设备令牌)。

为GCM配置项目

---

更新AndroidManifest文件

为了在我们的项目中启用GCM，我们需要在我们的清单文件中添加一些权限 转到AndroidManifest.xml并添加以下代码 添加权限

<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="android.permission.VIBRATE" />

<uses-permission android:name=“.permission.RECEIVE" />
<uses-permission android:name=“<your_package_name_here>.permission.C2D_MESSAGE" />
<permission android:name=“<your_package_name_here>.permission.C2D_MESSAGE"
        android:protectionLevel="signature" />

添加GCM广播接收器声明

在应用程序标签中添加GCM广播接收器声明

<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="" />
            </intent-filter]]>

        </receiver]]>
     
<application/>

添加GCM服务声明

<application
     <service android:name=".GcmIntentService" />
<application/>

---

获取注册ID(用于推送通知的设备令牌)

现在转到启动/启动活动

添加常量和类变量

private final static int PLAY_SERVICES_RESOLUTION_REQUEST = 9000;
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 String TAG = "LaunchActivity";
protected String SENDER_ID = "Your_sender_id";
private GoogleCloudMessaging gcm =null;
private String regid = null;
private Context context= null;

更新OnCreate和OnResume方法

@Override
protected void onCreate(Bundle savedInstanceState)
{
     super.onCreate(savedInstanceState);
     setContentView(R.layout.activity_launch);
     context = getApplicationContext();
         if (checkPlayServices()) 
     {
            gcm = GoogleCloudMessaging.getInstance(this);
            regid = getRegistrationId(context);

            if (regid.isEmpty())
            {
                registerInBackground();
            }
            else
            {
            Log.d(TAG, "No valid Google Play Services APK found.");
            }
      }
 }

@Override protected void onResume()
{
       super.onResume();       checkPlayServices();
}


# Implement GCM Required methods (Add below methods in LaunchActivity)

private boolean checkPlayServices() {
        int resultCode = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);
        if (resultCode != ConnectionResult.SUCCESS) {
            if (GooglePlayServicesUtil.isUserRecoverableError(resultCode)) {
                GooglePlayServicesUtil.getErrorDialog(resultCode, this,
                        PLAY_SERVICES_RESOLUTION_REQUEST).show();
            } else {
                Log.d(TAG, "This device is not supported - Google Play Services.");
                finish();
            }
            return false;
        }
        return true;
 }

private String getRegistrationId(Context context) 
{
   final SharedPreferences prefs = getGCMPreferences(context);
   String registrationId = prefs.getString(PROPERTY_REG_ID, "");
   if (registrationId.isEmpty()) {
       Log.d(TAG, "Registration ID not found.");
       return "";
   }
   int registeredVersion = prefs.getInt(PROPERTY_APP_VERSION, Integer.MIN_VALUE);
   int currentVersion = getAppVersion(context);
   if (registeredVersion != currentVersion) {
        Log.d(TAG, "App version changed.");
        return "";
    }
    return registrationId;
}

private SharedPreferences getGCMPreferences(Context context) 
{
    return getSharedPreferences(LaunchActivity.class.getSimpleName(),
                Context.MODE_PRIVATE);
}

private static int getAppVersion(Context context) 
{
     try 
     {
         PackageInfo packageInfo = context.getPackageManager()
                    .getPackageInfo(context.getPackageName(), 0);
            return packageInfo.versionCode;
      } 
      catch (NameNotFoundException e) 
      {
            throw new RuntimeException("Could not get package name: " + e);
      }
}


private void registerInBackground() 
{     new AsyncTask() {
     Override
     protected Object doInBackground(Object... params) 
     {
          String msg = "";
          try 
          {
               if (gcm == null) 
               {
                        gcm = GoogleCloudMessaging.getInstance(context);
               }
               regid = gcm.register(SENDER_ID);               Log.d(TAG, "########################################");
               Log.d(TAG, "Current Device's Registration ID is: "+msg);     
          } 
          catch (IOException ex) 
          {
              msg = "Error :" + ex.getMessage();
          }
          return null;
     }     protected void onPostExecute(Object result) 
     { //to do here };
  }.execute(null, null, null);
}

---

注意:请存储REGISTRATION_KEY，这对于发送PN消息给GCM很重要 也保持在我的这将是唯一的所有设备，通过使用这个只有GCM将发送推送通知。

接收推送通知

添加GCM广播接收机类

因为我们已经在我们的Manifest文件中声明了“GcmBroadcastReceiver.java”，所以让我们创建这个类 以这种方式更新接收器类代码

public class GcmBroadcastReceiver extends WakefulBroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) 
    {        ComponentName comp = new ComponentName(context.getPackageName(),
                GcmIntentService.class.getName());        startWakefulService(context, (intent.setComponent(comp)));
        setResultCode(Activity.RESULT_OK);
        Toast.makeText(context, “wow!! received new push notification", Toast.LENGTH_LONG).show();
    }
}

添加GCM服务分类

因为我们已经在我们的Manifest文件中声明了“GcmBroadcastReceiver.java”，所以让我们创建这个类 以这种方式更新接收器类代码

public class GcmIntentService extends IntentService
{     public static final int NOTIFICATION_ID = 1;     private NotificationManager mNotificationManager;     private final static String TAG = "GcmIntentService";     public GcmIntentService() {
     super("GcmIntentService");     
     }     @Override
     protected void onHandleIntent(Intent intent) {
          Bundle extras = intent.getExtras();
          Log.d(TAG, "Notification Data Json :" + extras.getString("message"));

          GoogleCloudMessaging gcm = GoogleCloudMessaging.getInstance(this);
          String messageType = gcm.getMessageType(intent);          if (!extras.isEmpty()) {          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.d(TAG," Working... " + (i + 1) + "/5 @ "
               + SystemClock.elapsedRealtime());               try {
                    Thread.sleep(5000);
               } catch (InterruptedException e) {
               }
             }
             Log.i(TAG, "Completed work @ " + SystemClock.elapsedRealtime());
             sendNotification(extras.getString("message"));
           }
        }        // 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, LaunchActivity.class), 0);

          NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(          this)
          .setSmallIcon(R.drawable.icon)
          .setContentTitle("Ocutag Snap")
          .setStyle(new NotificationCompat.BigTextStyle().bigText(msg))
          .setContentText(msg)
          .setDefaults(Notification.DEFAULT_SOUND | Notification.DEFAULT_VIBRATE);

          mBuilder.setContentIntent(contentIntent);          mNotificationManager.notify(NOTIFICATION_ID, mBuilder.build());
     }
}

谷歌的官方答案是Android云到设备消息框架(已弃用)谷歌云消息(已弃用)Firebase云消息

它将适用于Android >= 2.2(在有Play Store的手机上)。

Firebase Cloud Messaging (FCM)是GCM的新版本。FCM是一种跨平台消息传递解决方案，允许您安全地免费发送消息。继承GCM的中央基础设施，在Android, iOS, Web (javascript)， Unity和c++上可靠地传递消息。

截至2018年4月10日，谷歌已不批准GCM。GCM服务器和客户端api已弃用，将于2019年4月11日移除。谷歌建议将GCM应用程序迁移到Firebase Cloud Messaging (FCM)， FCM继承了可靠且可扩展的GCM基础设施。

资源