Update Elements in a Jsonobject

How to replace value in json file

You can try this with simple json library(library) . I am separately printed all object for understanding. AS you declare Id object inside two more object, so firstly you have to get this object then get your desire object IDNew. Then put new id value in id field.

import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.Iterator;

import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;

public class Main {

    private static final String filePath = "E:\\project-test\\scloud\\test\\src\\main\\resources\\test";

    public static void main(String[] args) {

        try {
            // read the json file
            FileReader reader = new FileReader(filePath);

            JSONParser jsonParser = new JSONParser();
            JSONObject jsonObject = (JSONObject) jsonParser.parse(reader);

            System.out.println(jsonObject);


            JSONObject addedObj = (JSONObject) jsonObject.get("Added");
            System.out.println("Added is: " + addedObj);

            JSONObject newmemObject =(JSONObject) addedObj.get("newmem");
            System.out.println("newmemObject is: " + newmemObject);

            JSONObject idNewObj =(JSONObject) newmemObject.get("IDNew");
            System.out.println("IdNewObj is: " + idNewObj);

            long id =Long.valueOf((String) idNewObj.get("id"));
            System.out.println(id);


            idNewObj.put("id",809809809);

            System.out.println(jsonObject);

        } catch (FileNotFoundException ex) {
            ex.printStackTrace();
        } catch (IOException ex) {
            ex.printStackTrace();
        } catch (ParseException ex) {
            ex.printStackTrace();
        } catch (NullPointerException ex) {
            ex.printStackTrace();
        }

    }

}

Or for simplicity you can use this

    FileReader reader = new FileReader(filePath);
    JSONParser jsonParser = new JSONParser();
    JSONObject jsonObject = (JSONObject) jsonParser.parse(reader);
    System.out.println(jsonObject);

    JSONObject idObj = (
       (JSONObject) (
             (JSONObject) (
                (JSONObject)
                   jsonObject.get("Added")
             ).get("newmem")
       ).get("IDNew")
    );

    idObj.put("id", 98009809);
    System.out.println("After ID value updated : "+jsonObject);

How to modify values of JsonObject / JsonArray directly?

Strangely, the answer is to keep adding back the property. I was half expecting a setter method. :S

System.out.println("Before: " + obj.get("DebugLogId")); // original "02352"

obj.addProperty("DebugLogId", "YYY");

System.out.println("After: " + obj.get("DebugLogId")); // now "YYY"

Update inner object element in Json using Gson

Updated code slightly and pass parameters as suggested by @Smile answer

keyPath : reqParams/headerId
          someId (if exist in root level)

Code :

public String updateValue(String keyPath, String updateText, String jsonText) {
    String[] keys = keyPath.split("/");
    JsonParser jsonParser = new JsonParser();
    JsonObject jsonObject = (JsonObject) jsonParser.parse(jsonText);
    JsonObject returnVal = jsonObject; // This holds the ref to target json object
    JsonPrimitive jp = new JsonPrimitive(updateText);
    String finalKey = keys[keys.length - 1];
    for (String key : keys) {

    if (jsonObject.get(key) != null && jsonObject.get(key).isJsonObject()) {
        jsonObject = (JsonObject) jsonObject.get(key);
        jsonObject.remove(finalKey);
        jsonObject.add(finalKey, jp);
        return returnVal.toString();
    } else if (jsonObject.get(finalKey) == null) {
        return returnVal.toString();
    }
}

jsonObject.remove(finalKey);
jsonObject.add(finalKey, jp);
return returnVal.toString();

}

How to modify values of JsonObject

How about something like this?

private static void statDup(final JSONObject o) {
    if (o.containsKey("properties")) {
        final JSONArray a = (JSONArray) o.get("properties");
        for (final Object e : a) {
            final JSONObject p = (JSONObject) e;
            p.put(p.get("stat"), p.get("data"));
        }
    } else {
        for (final Object key : o.keySet()) {
            final Object value = o.get(key);
            if (value instanceof JSONArray) {
                for (final Object e : (JSONArray) value) {
                    statDup((JSONObject) e);
                }
            }
        }
    }
}

Update json element in json object

You need to look for the USDT-BTC and change the price:

 for (var i in json.result) {
     var item = json.result[i];

     if (item.MarketName == 'USDT-BTC') {
         item.Price = 17000.00000001;
     }
 }

Other way using map:

 json.result = json.result.map(item => (
     item.MarketName == 'USDT-BTC' ?
         { ...item, price: 17000.00000001} : item );
 )

updating a JSON object in a list of JSON objects

In React you can't update state directly. so by doing

let todos = [...this.state.todos];

It create a copy of the todos property which is in the state and It doesn't reference to the value which is in the state.

let todoId = 2;
let todos = [
    {id: 1, name: "todo 1", done: false},
    {id: 2, name: "todo 1", done: false},
    {id: 3, name: "todo 1", done: false}
]

let todo = todos.find((todo) => todo.id == todoId);


// if I update any attribute of the previous toto variable it will also update it value in the `todos`

todo.name = "updated todo name";

console.log(todos);

    public static JSONObject setProperty(JSONObject js1, String keys, String valueNew) throws JSONException {
    String[] keyMain = keys.split("\\.");
    for (String keym : keyMain) {
        Iterator iterator = js1.keys();
        String key = null;
        while (iterator.hasNext()) {
            key = (String) iterator.next();
            if ((js1.optJSONArray(key) == null) && (js1.optJSONObject(key) == null)) {
                if ((key.equals(keym))) {
                    js1.put(key, valueNew);
                    return js1;
                }
            }
            if (js1.optJSONObject(key) != null) {
                if ((key.equals(keym))) {
                    js1 = js1.getJSONObject(key);
                    break;
                }
            }
            if (js1.optJSONArray(key) != null) {
                JSONArray jArray = js1.getJSONArray(key);
                for (int i = 0; i < jArray.length(); i++) {
                    js1 = jArray.getJSONObject(i);
                }
                break;
            }
        }
    }
    return js1;
}

public static void main(String[] args) throws IOException, JSONException {
    FileInputStream inFile = new FileInputStream("/home/ermek/Internship/labs/java/task/test5.json");
    byte[] str = new byte[inFile.available()];
    inFile.read(str);
    String text = new String(str);
    JSONObject json = new JSONObject(text);
    setProperty(json, "rpc_server_type", "555");
    System.out.println(json.toString(4));

JSONArray users = (JSONArray) JSONValue.parse(json);
JSONObject firstUser = (JSONObject) users.get(0);

JSONArray firstUserGoals = (JSONArray) firstUser.get("Goals");
JSONObject firstUserFirstGoal = (JSONObject) firstUserGoals.get(0);

JSONArray firstUserFirstGoalMilestones = (JSONArray) firstUserFirstGoal.get("milestones");
JSONObject firstUserFirstGoalFirstMilestone = (JSONObject) firstUserFirstGoalMilestones.get(0);

firstUserFirstGoalFirstMilestone.put("milestoneName", "Chapter 0");

JSONObject milestone1 = new JSONObject();
milestone1.put("milestoneName", "Chapter 1");
milestone1.put("Difficulty", "H");
milestone1.put("dueDate", "02/18/2018");
milestone1.put("completed", true);

firstUserFirstGoalMilestones.add(1, milestone1);

String finalJson = users.toJSONString();

Writer writer = new FileWriter(path);
users.writeJSONString(writer);
writer.close();