Firebase onMessageReceived not called when app in background

This is working as intended, notification messages are delivered to your onMessageReceived callback only when your app is in the foreground. If your app is in the background or closed then a notification message is shown in the notification center, and any data from that message is passed to the intent that is launched as a result of the user tapping on the notification.

You can specify a click_action in your JSON to indicate the intent that should be launched when the notification is tapped by the user. The main activity is used if no click_action is specified.

When the intent is launched you can use the

getIntent().getExtras();

to retrieve a Set that would include any data sent along with the notification message.

For more on notification message see docs.

Here is more clear concepts about firebase message. I found it from their support team.

Firebase has three message types:

Notification messages : Notification message works on background or foreground. When app is in background, Notification messages are delivered to the system tray. If the app is in the foreground, messages are handled by onMessageReceived() or didReceiveRemoteNotification callbacks. These are essentially what is referred to as Display messages.

Data messages: On Android platform, data message can work on background and foreground. The data message will be handled by onMessageReceived(). A platform specific note here would be: On Android, the data payload can be retrieved in the Intent used to launch your activity. To elaborate, if you have "click_action":"launch_Activity_1", you can retrieve this intent through getIntent() from only Activity_1.

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.

Also, I recommend you to use onMessageReceived method (see Data message) to extract the data bundle. From your logic, I checked the bundle object and haven't found expected data content. Here is a reference to a similar case which might provide more clarity.

From server side, firebase notification should bellow format:

Server side should send "notification" object. Lacks of "notification" object in my TargetActivity didn't getting message using getIntent().

Correct message format is given bellow:

{
 "data": {
  "body": "here is body",
  "title": "Title"
 },
"notification": {
  "body": "here is body",
  "title": "Title",
  "click_action": "YOUR_ACTION"
 },
 "to": "ffEseX6vwcM:APA91bF8m7wOF MY FCM ID 07j1aPUb"
}

Here is more clear concepts about firebase message. I found it from their support team.

For more info visit my this thread and this thread

this method handleIntent() has been depreciated, so handling a notification can be done as below:

1. Foreground State: The click of the notification will go to the pending Intent's activity which you are providing while creating a notification pro-grammatically as it generally created with data payload of the notification.

2. Background/Killed State - Here, the system itself creates a notification based on notification payload and clicking on that notification will take you to the launcher activity of the application where you can easily fetch Intent data in any of your life-cycle methods.

Remove notification field completely from your server request. Send only data and handle it in onMessageReceived() otherwise your onMessageReceived() will not be triggered when app is in background or killed.

Don't forget to include "priority": "high" field in your notification request. According to the documentation: data messages are sent with a normal priority, thus they will not arrive instantly; it could also be the problem.

Here is what I am sending from server

{
  "data":{
    "id": 1,
    "missedRequests": 5
    "addAnyDataHere": 123
  },
  "to": "fhiT7evmZk8:APA91bFJq7Tkly4BtLRXdYvqHno2vHCRkzpJT8QZy0TlIGs......",
  "priority": "high"
}

So you can receive your data in onMessageReceived(RemoteMessage message) like this....let say I have to get id

Object obj = message.getData().get("id");
        if (obj != null) {
            int id = Integer.valueOf(obj.toString());
        }