how to create a json from java object code example

Example 1: build json object in java

String jsonString = new JSONObject()
                  .put("JSON1", "Hello World!")
                  .put("JSON2", "Hello my World!")
                  .put("JSON3", new JSONObject().put("key1", "value1"))
                  .toString();

System.out.println(jsonString);

Example 2: build json object in java

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