How can we encode a JSON object in Java?

A JSONObject is a subclass of java.util.HashMap where no order is provided. We can also use the strict ordering of elements as well with the help of the JSONValue.toJSONString(map) method i.e. by the implementation of java.util.LinkedHashMap.

We can encode a JSON object in the below two examples.

Example 

import java.util.*;
import org.json.simple.JSONObject;
public class JSONEncodingTest {
   public static void main(String[] args) {
      Map<Object, Object> dataMap = new HashMap<Object, Object>();
      dataMap.put("Name", "Adithya");
      dataMap.put("Age", new Integer(25));
      dataMap.put("Salary", new Double(25000.00));
      dataMap.put("Employee Id", new Integer(115));
      dataMap.put("Company", "TutorialsPoint");
      JSONObject jsonObj = new JSONObject(dataMap);
      System.out.print("Encoding a JSON object: ");
      System.out.print(jsonObj);
   }
}

Output

Encoding a JSON object: {"Salary":25000.0,"Employee id":115,"Company":"TutorialsPoint","Age":25,"Name":"Adithya"}

Example 

import java.io.*;
import org.json.simple.*;
public class JSONEncodingTest1 {
   public static void main(String[] args) throws IOException {
      JSONObject obj = new JSONObject();
      obj.put("Name", "Jai");
      obj.put("Mobile_Number", new Integer(995998480));
      obj.put("Bank_Balance", new Double(50000.00));
      obj.put("Is_A_SelfEmployee", new Boolean(false));
      StringWriter out = new StringWriter();
      obj.writeJSONString(out);
      String jsonText = out.toString();
      System.out.print(jsonText);
   }
}

Output

{"Is_A_SelfEmployee":false,"Bank_Balance":50000.0,"Mobile_Number":995998480,"Name":"Jai"}