How to parse Json data in android for Firebase Clo

问题:

i am using FCM for push messages and handling all incoming push notification in onMessageReceived. Now the issue is with parsing nested json that comes inside this function remoteMessage.getData()

I have following block coming as a push notification in device. content of data payload could be varied here it is dealer later on it can be productInfo

{
  "to": "/topics/DATA",
  "priority": "high",
  "data": {
    "type": 6,
    "dealerInfo": {
      "dealerId": "358",
      "operationCode": 2
    }
  }
}

this how i am parsing it

 if(remoteMessage.getData()!=null){

        JSONObject object = null;
        try {
            object = new JSONObject(remoteMessage.getData());       

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


    }

now i am getting data with blackslashes as remoteMessage.getData() returns Map<String,String> so probably my nested block is being converted in string not sure though.

{
  "wasTapped": false,
  "dealerInfo": "{\"dealerId\":\"358\",\"operationCode\":2}",
  "type": "6"
}

and if i write object = new JSONObject(remoteMessage.getData().toString()); then it got failed with following notification

{
  "to": "regid",
  "priority": "high",
  "notification" : {
      "body": "Message Body",
      "title" : "Call Status",
      "click_action":"FCM_PLUGIN_ACTIVITY"
   },
  "data": {
    "type": 1,
     "callNumber":"ICI17012702",
     "callTempId":"0",
      "body": "Message Body",
      "title" : "Call Status"
  }
}

error i get is

> org.json.JSONException: Unterminated object at character 15 of
> {body=Message Body, type=1, title=Call Status, callNumber=ICI17012702,
> callTempId=0}

回答1:

try this code:

public void onMessageReceived(RemoteMessage remoteMessage)
    {
        Log.e("DATA",remoteMessage.getData().toString());
        try
        {
            Map<String, String> params = remoteMessage.getData();
            JSONObject object = new JSONObject(params);
            Log.e("JSON OBJECT", object.toString());
            String callNumber = object.getString("callNumber");
            //rest of the code
      }
   }

Also make sure your JSON is valid use This

回答2:

Faced this issue when migrating from GCM to FCM.

The following is working for my use case (and OP payload), so perhaps it will work for others.

JsonObject jsonObject = new JsonObject(); // com.google.gson.JsonObject
JsonParser jsonParser = new JsonParser(); // com.google.gson.JsonParser
Map<String, String> map = remoteMessage.getData();
String val;

for (String key : map.keySet()) {
    val = map.get(key);
    try {
        jsonObject.add(key, jsonParser.parse(val));
    } catch (Exception e) {
        jsonObject.addProperty(key, val);
    }
}

// Now you can traverse jsonObject, or use to populate a custom object:
// MyObj o = new Gson().fromJson(jsonObject, MyObj.class)

回答3:

Since dealerInfo is parsed as string and not an object, create a new JSONObject with the string

JSONObject dealerInfo = new JSONObject(object.getString("dealerInfo"));
String dealerId = dealerInfo.getString("dealerId");
String operationCode = dealerInfo.getString("operationCode");

回答4:

I have changed to

JSONObject json = new JSONObject(remoteMessage.getData());

from

JSONObject json = new JSONObject(remoteMessage.getData().toString());

and work fine.

回答5:

I didn't want to add GSON (as I use moshi) to make it working, so I made Kotlin method to form json string from remoteMessage's map, tested this on one example, so don't forget to test this implementation before using:

override fun onMessageReceived(remoteMessage: RemoteMessage?) {
        super.onMessageReceived(remoteMessage)

        var jsonString = "{"

        remoteMessage?.data?.let {
            val iterator = it.iterator()

            while (iterator.hasNext()) {
                val mapEntry = iterator.next()
                jsonString += "\"${mapEntry.key}\": "
                val value = mapEntry.value.replace("\\", "")
                if (isValueWithoutQuotes(value)) {
                    jsonString += value
                } else {
                    jsonString += "\"$value\""
                }

                if (iterator.hasNext()) {
                    jsonString += ", "
                }
            }
        }

        jsonString += "}"


        println(jsonString)
    }

    private fun isValueWithoutQuotes(value: String):Boolean{
       return (value == "true" || value == "false" || value.startsWith("[") || value.startsWith("{") || value == "null" || value.toIntOrNull() != null )
    }

Edit:

Even better approach is to form FCM data like:

notificationType: "here is ur notification type"
notificationData: {
//here goes ur data
}

That way we can retreive both values from map.

remoteMessage?.data?.let {
    it["notificationData"]?.let {
         jsonString = it.replace("\\", "")
    }
}

We got clear json without "playing" around. And we can then use notificationType to convert json to the object that we need (as several notification data types can be passed sometimes)