how to create json object in java code example

Example 1: new jsonobject java

String message;
JSONObject json = new JSONObject();
json.put("name", "student");

JSONArray array = new JSONArray();
JSONObject item = new JSONObject();
item.put("information", "test");
item.put("id", 3);
item.put("name", "course1");
array.add(item);

json.put("course", array);

message = json.toString();

// message
// {"course":[{"id":3,"information":"test","name":"course1"}],"name":"student"}

Example 2: creating json object in java

import org.json.simple.JSONObject;

class JsonEncodeDemo {

   public static void main(String[] args) {
	
      JSONObject obj = new JSONObject();

      obj.put("name","foo");
      obj.put("num",new Integer(100));
      obj.put("balance",new Double(1000.21));
      obj.put("is_vip",new Boolean(true));

      StringWriter out = new StringWriter();
      obj.writeJSONString(out);
      
      String jsonText = out.toString();
      System.out.print(jsonText);
   }
}

Example 3: build json object in java

String json = Json.createObjectBuilder()
            .add("key1", "value1")
            .add("key2", "value2")
            .build()
            .toString();