如何从 android 中的原始有效载荷中提取价值？

Question

I am trying to extract google.sent_time from the following JSON, how do I get that value?
It seems like it's a raw payload, and not straightforward JSON, so wondering if there is a way to extract it?

{
  "notificationID": "677291f5-a784-43df-af2e-0067e9c",
  "title": "test 223",
  "body": "payload",
  "lockScreenVisibility": 1,
  "groupMessage": "",
  "fromProjectNumber": "819539062812",
  "priority": 5,
  "rawPayload": "{\"google.delivered_priority\":\"normal\",\"google.sent_time\":1591849563191,\"google.ttl\":259200,\"google.original_priority\":\"normal\",\"custom\":\"{\\\"i\\\":\\\"677291f5-a784-43df-af2e-0363a4067e9c\\\"}\",\"oth_chnl\":\"\",\"pri\":\"5\",\"vis\":\"1\",\"from\":\"819539062812\",\"alert\":\"payload\",\"title\":\"test 223\",\"grp_msg\":\"\",\"google.message_id\":\"0:1591849563205759%409ebbcaf9fd7ecd\",\"google.c.sender.id\":\"819539062812\",\"notificationId\":-1451117355}"
}

Answer 1

It is JSON, with some characters escaped so it can fit in to a string type field in your main JSON.

You can extract the string value of "rawPayload" field an feed that to whatever JSON parser you are using, or you can use a regex directly on the string to get just the value:

Here is a regex example:

Pattern p = Pattern.compile("google\\.sent_time.*:(\\d+)");
Matcher m = p.matcher(yourInputString);
m.find();
String sentTime = m.group(1);

Answer 2

Get the rawPayload value as string from the original JSON and wrap it around JSONObject again:

public static void main(String[] args) throws Exception {
    String str = "...";     // JSON string here
    
    JSONObject json = new JSONObject(str);
    
    JSONObject payload = new JSONObject(json.getString("rawPayload"));
    System.out.println(payload.toString());
}

Output:

{
   "google.delivered_priority":"normal",
   "google.sent_time":1591849563191,
   "google.ttl":259200,
   "google.original_priority":"normal",
   "custom":"{\"i\":\"677291f5-a784-43df-af2e-0363a4067e9c\"}",
   "oth_chnl":"",
   "pri":"5",
   "vis":"1",
   "from":"819539062812",
   "alert":"payload",
   "title":"test 223",
   "grp_msg":"",
   "google.message_id":"0:1591849563205759%409ebbcaf9fd7ecd",
   "google.c.sender.id":"819539062812",
   "notificationId":-1451117355
}

The org.json library is used for the example.

Answer 3

Use Gson json parser. What it does is map your json data to POJO class. But since you don't care about the other items or you don't wanna use Gson you'll have to have to go:

    JSONObject obj = new 
  JSONObject(YOUR_JSON_DATA);
   JSONObject notiObj = 
  obj.getJSONObject("rawPayload");
  String sentTime =  notiObj.getString("google.sent_time);

Cheers!

Answer 4

rawPayload looks like a valid JSON, you can check this using any online json formatter. You can try this:

val str = "{\"google.delivered_priority\":\"normal\",\"google.sent_time\":1591849563191,\"google.ttl\":259200,\"google.original_priority\":\"normal\",\"custom\":\"{\\\"i\\\":\\\"677291f5-a784-43df-af2e-0363a4067e9c\\\"}\",\"oth_chnl\":\"\",\"pri\":\"5\",\"vis\":\"1\",\"from\":\"819539062812\",\"alert\":\"payload\",\"title\":\"test 223\",\"grp_msg\":\"\",\"google.message_id\":\"0:1591849563205759%409ebbcaf9fd7ecd\",\"google.c.sender.id\":\"819539062812\",\"notificationId\":-1451117355}"

    try {
        val key = "google.sent_time"
        val json = JSONObject(str)
        Log.i(javaClass.simpleName, "key = ${json[key]}")
    } catch (e: Exception) {
        Log.e(javaClass.simpleName, "failed :", e)
    }