toJSONString() is undefined for the type JSONObject

Question

My code to create a new JSONObject and write to a file:

JSONObject obj = new JSONObject();
obj.put(\"name\", \"abcd\");
obj.put(\"age\", new Integer(100));
J         


        

Answer 1

Simply stringifying the JsonObject will not work. Using json-simple 3.1.0, JsonObject.toString() will not write the object as valid JSON.

Given the JSON Object as:

JsonObject my_obj = new JsonObject();
my_obj.put("a", 1);
my_obj.put("b", "z");
my_obj.put("c", true);

file.write(my_obj.toString());

Will save as

{a=1, b=z, c=true}

Which is not valid JSON.

To fix this, you need to use the Jsoner.

Working Example

import com.github.cliftonlabs.json_simple.JsonObject;
import com.github.cliftonlabs.json_simple.Jsoner;

import java.io.BufferedWriter;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;

public class Example {

    public static void main(String args[]) {
        JsonObject my_obj = new JsonObject();
        my_obj.put("a", 1);
        my_obj.put("b", "z");
        my_obj.put("c", true);

        try {
            BufferedWriter writer = Files.newBufferedWriter(Paths.get("test.json"));
            Jsoner.serialize(my_obj, writer);
            writer.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Which saves as

{"a":1,"b":"z","c":true}

Which is valid JSON.

Answer 2

The method toJSONString() is from json-simple but I guess you are using org.json.

org.json have an alternative to toJSONString(). You can simply use: obj.toString(1).

The difference to the toString() method is, that if you pass "1" as parameter org.json automatically will format and beautify your JSON. So you don't have only one single compressed line of JSON in your file.

Answer 3

I meet the same question, if you want to use toJSONString() you need to import json-simple-1.1.jar library.

Answer 4

The JSONObject class doesn't have a toJSONString() method. Instead it overrides the toString() method to generate json.

To get the json representation of the object, simply use obj.toString().