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\"}}"

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
    */
}

根据文件显示，2017年5月17日

当你的应用在后台时，Android 将通知消息定向到系统托盘。用户轻按 通知默认打开应用程序启动器。 这包括同时包含通知和数据有效负载的消息 (以及从Notifications控制台发送的所有消息)。在这些 在情况下，通知被传递到设备的系统托盘，和 数据有效负载是在您的意图的附加部分中交付的 发射器的活动。

所以，你应该同时使用有效负载通知和数据:

{
  "to": "FCM registration ID",
  "notification": {
    "title" : "title",
    "body"  : "body text",
    "icon"  : "ic_notification"
   },
   "data": {
     "someData"  : "This is some data",
     "someData2" : "etc"
   }
}

不需要使用click_action。你应该从LAUNCHER活动中获得额外的意图

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

Java代码应该在MainActivity的onCreate方法上:

Intent intent = getIntent();
if (intent != null && intent.getExtras() != null) {
    Bundle extras = intent.getExtras();
    String someData= extras.getString("someData");
    String someData2 = extras.getString("someData2");
}

您可以从Firebase Notifications Console测试有效负载通知+数据。不要忘记在高级选项部分填写自定义数据字段

我想出了各种方案

当app在前台时， onMessageReceived()方法从FirebaseService调用。因此，服务类中定义的pendingIntent将被调用。

当app在后台时，第一个activity被调用。

现在，如果你使用了一个splashactivity，那么必须记住splashactivity会被调用，否则如果没有splashactivity，那么无论第一个activity是什么，都会被调用。

然后你需要检查firstActivity的getIntent()，看看它是否有任何bundle。如果一切正常，你会看到bundle在那里，值被填充。如果从服务器发送的数据标签中的值是这样的，

"data": {
    "user_name": "arefin sajib",
    "value": "user name notification"
  }

然后在第一个活动中，你会看到， 有一个有效的意图(getIntent()不是null)，有效的捆绑包和在捆绑包内，会有上面提到的以数据为键的整个JSON。

在这种情况下，提取值的代码是这样的，

    if(getIntent()!=null){
            Bundle bundle = getIntent().getExtras();
            if (bundle != null) {
                try {
                   JSONObject object = new JSONObject(bundle.getStringExtra("data"));
String user_name = object.optString("user_name");

                } catch (JSONException e) {
                    e.printStackTrace();
                }


            }
        }

感谢你们所有人的回答。但是我通过发送数据消息而不是发送通知来解决这个问题。 服务器代码

<?php
$url = "https://fcm.googleapis.com/fcm/send";
$token = "C-l6T_a7HouUK****";
$serverKey = "AAAAaOcKS00:********";
define( 'API_ACCESS_KEY', $serverKey );
$registrationIds = array($token);
// prep the bundle

$msg = array

(
 'message'  => 'here is a message. message',
 'title'        => 'This is a title. title',
 'subtitle' => 'This is a subtitle. subtitle',
 'tickerText'   => 'Ticker text here...Ticker text here...Ticker text 
 here',
 'vibrate'  => 1,
 'sound'        => 1,
 'largeIcon'    => 'large_icon',
 'smallIcon'    => 'small_icon'

);

$fields = array

(
  'registration_ids'    => $registrationIds,
  'data'            => $msg

);
$headers = array

(
  'Authorization: key=' . API_ACCESS_KEY,
 'Content-Type: application/json'

);


$ch = curl_init();

curl_setopt( $ch,CURLOPT_URL, 'https://android.googleapis.com/gcm/send' 
);

curl_setopt( $ch,CURLOPT_POST, true );

curl_setopt( $ch,CURLOPT_HTTPHEADER, $headers );

curl_setopt( $ch,CURLOPT_RETURNTRANSFER, true );

curl_setopt( $ch,CURLOPT_SSL_VERIFYPEER, false );

curl_setopt( $ch,CURLOPT_POSTFIELDS, json_encode( $fields ) );

$result = curl_exec($ch );

curl_close( $ch );

echo $result;

?>

并在onmessagerreceived中捕获数据

public class MyFirebaseMessagingService extends FirebaseMessagingService     {

  private static final String TAG = "MyFirebaseMsgService";

@Override
public void onMessageReceived(RemoteMessage remoteMessage) {
    Log.d(TAG, "From: " + remoteMessage.getFrom());

    // Check if message contains a data payload.
    if (remoteMessage.getData().size() > 0) {
        Log.d(TAG, "Message data payload: " + remoteMessage.getData());

      sendNotification(remoteMessage.getData().get("message"));
     }
   // Check if message contains a notification payload.
    else if (remoteMessage.getNotification() != null) {
        Log.d(TAG, "Message Notification Body: " + remoteMessage.getNotification().getBody());
    sendNotification(remoteMessage.getNotification().getBody());
    }


}
   private void sendNotification(String messageBody) {
    Intent intent = new Intent(this, Notify.class).putExtra("msg",messageBody);
    intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
    PendingIntent pendingIntent = PendingIntent.getActivity(this, 0 /* Request code */, intent,
            PendingIntent.FLAG_ONE_SHOT);

    String channelId = "idddd";
    Uri defaultSoundUri= RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
    NotificationCompat.Builder notificationBuilder =
            new NotificationCompat.Builder(MyFirebaseMessagingService.this)
                    .setSmallIcon(R.mipmap.ic_launcher)
                    .setContentTitle("FCM Message")
                    .setContentText(messageBody)
                    .setAutoCancel(true)
                    .setSound(defaultSoundUri)
                    .setContentIntent(pendingIntent);

    NotificationManager notificationManager =
            (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);

    notificationManager.notify(0 /* ID of notification */, notificationBuilder.build());
}
}

2023年1月 对于那些实现了最新的Firebase云消息(FCM)的应用程序，您可能不会被限制在后台或完全关闭的情况下分别为应用程序发送数据和通知以处理数据。正如这里的一些回答所解释的那样，简短的版本是:

在你的启动器活动上，监视启动时的额外内容; 测试您的FCM数据中的唯一键是否在列表中; 如果存在，获取必要的数据并调用您的活动来处理您想要做的处理。

//Firebase
// [START handle_data_extras]
if (getIntent().getExtras() != null) {
    boolean fcmExtraFlag = false;
    for (String key : getIntent().getExtras().keySet()) {
        Object value = getIntent().getExtras().get(key);
        Log.d(TAG, "Key: " + key + " Value: " + value);
        if(key.equalsIgnoreCase("tracerId")){
            //test your known key to be sure it is from fcm
            //this must have come from notification (system) tray
            //this will come whether the app was in the background or completely off
            //generally, this could be in the main activity as it has the intent-filter already set
            fcmExtraFlag = true;
        }
    }
    //pick fcm values if present and notify and/or process accordingly
    //you may add time-lookup to ignore delayed (time-passed) ones; and ignore
    if(fcmExtraFlag){
        String tracerId = (String) getIntent().getExtras().get("tracerId"); 
        //prepare your data as needed
        String tracerData = tracerId+">"+data-one+">"+data-two;
        String msgBody = "This is a test notification; data received: "+tracerId;
        String fcmMessage = msgBody;
        //start your confirmation activity, directly or whichever way
        SidUtils.firebaseStartConfirms(msgBody, tracerData, this);
    }
}
// [END handle_data_extras]

如前所述，如果可能的话，这应该在你的主活动中，以处理你的应用程序实际上关闭的情况-而不仅仅是在后台。这些将通过点击系统托盘上的应用程序通知来触发。