JSON

Here's an example that shows how to play around with JSON objects in java. There are a bunch of JSON libraries. This example users json.org.

checkout the code here

package org.megha.blog.example.json;

import org.json.JSONArray;

import org.json.JSONObject;

/**

* Play around with {@code json.org}'s JSON library.

* To run this, you import the library from json.org.

*

* @author megha birmiwal

*/

public class JsonPrinter {

public static void main(String[] args) {

// create a json object from a json string

String responseData = "{'name':'Robert','interests':['Swimming','Music',123],"

+ "'address':{'city': 'Bangalore'}}";

JSONObject jsonObject = new JSONObject(responseData);

// convert back to "pretty-printed" string

System.out.println(jsonObject.toString(4));

// extract values from a json object

String name = jsonObject.getString("name");

System.out.println(name);

JSONArray jsonArray = jsonObject.getJSONArray("interests");

System.out.println(jsonArray.toString(2));

// json array has .length() and .getXXX(index) methods to get elements

// also has a .join() to join values into a string with the // specified separator

String interests = jsonArray.join(" ");

System.out.println(interests);

JSONObject address = jsonObject.getJSONObject("address");

String addressCity = address.getString("city");

System.out.println(addressCity);

// adding entries is trivial. just call put()

address.put("country", "India");

// difference between pretty-printed and condensed outputs

System.out.println(address.toString());

System.out.println(address.toString(2));

// note that it prints address with the added country

System.out.println(jsonObject.toString(4));

}

}