因为从Firebase通知UI发送的显示消息只在应用程序处于前台时有效。对于数据消息，需要对FCM进行POST调用

步骤

安装高级休息客户端谷歌Chrome扩展 添加以下头文件 关键字:Content-Type，值:application/json 密钥:授权，值:Key ="您的服务器密钥" 添加正文 如果使用主题: ｛ "to": "/topics/topic_name"， "数据":{ "key1": "value1"， "key2": "value2"， ｝ ｝ 如果使用注册id: ｛ "registration_ids": "[{"id"}，{id1}]"， "数据":{ "key1": "value1"， "key2": "value2"， ｝ ｝

它!。现在像往常一样收听onmessagerreceived回调。

@Override
public void onMessageReceived(RemoteMessage remoteMessage) { 
     Map<String, String> data = remoteMessage.getData();
     String value1 = data.get("key1");
     String value2 = data.get("key2");
}

根据文件

Handle messages in a backgrounded app When your app is in the background, Android directs notification messages to the system tray. A user tap on the notification opens the app launcher by default. This includes messages that contain both notification and data payload. In these cases, the notification is delivered to the device's system tray, and the data payload is delivered in the extras of the intent of your launcher Activity. If you want to open your app and perform a specific action, set click_action in the notification payload and map it to an intent filter in the Activity you want to launch. For example, set click_action to OPEN_ACTIVITY_1 to trigger an intent filter like the following:

 <intent-filter>   <action android:name="OPEN_ACTIVITY_1" />  
 <category android:name="android.intent.category.DEFAULT" />
 </intent-filter>

编辑:

基于这个线程:

不能使用Firebase Console设置click_action有效负载。您可以尝试使用curl命令或自定义http服务器进行测试

curl --header "Authorization: key=<YOUR_KEY_GOES_HERE>" 
     --header Content-Type:"application/json" https://fcm.googleapis.com/fcm/send  
     -d "{\"to\":\"/topics/news\",\"notification\": 
         {\"title\": \"Click Action Message\",\"text\": \"Sample message\",
            \"click_action\":\"OPEN_ACTIVITY_1\"}}"

下面是关于firebase消息的更清晰的概念。我从他们的支援组找到的。

Firebase有三种消息类型:

通知消息:通知消息工作在后台或前台。当app在后台时，通知消息被传递到系统托盘。如果应用程序在前台，消息由onmessagerreceived()或didReceiveRemoteNotification回调处理。这些实质上就是所谓的显示消息。

数据消息:在Android平台上，数据消息可以工作在后台和前台。数据消息将由onMessageReceived()处理。在Android上，数据有效载荷可以在用于启动你的活动的Intent中检索。具体来说，如果你有"click_action":"launch_Activity_1"，你只能通过getIntent()从Activity_1中检索这个意图。

Messages with both notification and data payloads: When in the background, apps receive the notification payload in the notification tray, and only handle the data payload when the user taps on the notification. When in the foreground, your app receives a message object with both payloads available. Secondly, the click_action parameter is often used in notification payload and not in data payload. If used inside data payload, this parameter would be treated as custom key-value pair and therefore you would need to implement custom logic for it to work as intended.

另外，我建议您使用onMessageReceived方法(参见数据消息)来提取数据包。根据您的逻辑，我检查了bundle对象，并没有发现预期的数据内容。这里有一个类似案例的参考，可能会更清楚。

欲了解更多信息，请访问我的这个线程

你要工作onmessagerreceived (RemoteMessage RemoteMessage)在后台只发送数据部分通知部分这:

"data":    "image": "",    "message": "Firebase Push Message Using API", 

"AnotherActivity": "True"， "to": "设备id或设备令牌"

通过这个onMessageRecivied是调用后台和前台不需要处理通知使用通知托盘在你的启动器活动。 处理数据负载使用这个:

  public void onMessageReceived(RemoteMessage remoteMessage)
    if (remoteMessage.getData().size() > 0) 
    Log.d(TAG, "Message data payload: " + remoteMessage.getData());      

要使firebase库在以下情况下调用onmessagerecreceived ()

应用程序在前台 后台应用程序 应用程序已被杀死

你不能把JSON键通知在你的请求到Firebase API，而是使用数据，见下文。

当你的应用程序处于后台或被杀死时，下面的消息将不会调用你的onmessagerreceived()，并且你不能自定义你的通知。

{
   "to": "/topics/journal",
   "notification": {
       "title" : "title",
       "text": "data!",
       "icon": "ic_notification"
    }
}

但是用这个方法就可以了

{
  "to": "/topics/dev_journal",
   "data": {
       "text":"text",
       "title":"",
       "line1":"Journal",
       "line2":"刊物"
   }
} 

基本上，消息是在参数RemoteMessage中与数据对象一起发送的，如Map<String, String>，然后您可以在这里的代码片段中管理onmessagerreceived中的通知

@Override
public void onMessageReceived(RemoteMessage remoteMessage) { 
     Map<String, String> data = remoteMessage.getData();

     //you can get your text message here.
     String text= data.get("text");


     NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this)
        // optional, this is to make beautiful icon
             .setLargeIcon(BitmapFactory.decodeResource(
                                    getResources(), R.mipmap.ic_launcher))  
        .setSmallIcon(smallIcon)  //mandatory
      .......
    /*You can read more on notification here:
    https://developer.android.com/training/notify-user/build-notification.html
    https://www.youtube.com/watch?v=-iog_fmm6mE
    */
}

我通过使用广播消息解决了这个问题。

创建一个Broadcast并从service worker中以Broadcast Message的形式发送有效负载。

然后在应用程序中接收有效负载并按您想要的方式处理它。