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.