Several ways to turn Java JSON string

　　package com.doit8.test.jsontest;

　　import java.util.ArrayList;

　　import java.util.List;

　　import com.alibaba.fastjson.JSON;

　　import com.alibaba.fastjson.JSONArray;

　　import com.alibaba.fastjson.JSONObject;

　　import com.doit8.test.jsontest.pojo.Card;

　　import com.doit8.test.jsontest.pojo.Person;

　　public class App

　　{

　　public static void main (String [] args)

　　{

　　//1.JSON string generated by the object, the object contains an array of objects converted into a string JSON.

　　Person person = new Person ();

　　person.setUsername ( "xiejava");

　　person.setSex ( "man");

　　person.setAge (38);

　　person.setEmail ( "xiejava @ ishareread.com ");

　　Card card1 = new Card ();

　　card1.setCardName ( "bankCard1");

　　card1.setCardCode ( "888888888");

　　card1.setCardValue (99999999);

　　Card card2 = new Card ();

　　card2.setCardName ( "bankCard1");

　　card2.setCardCode ( "999999999");

　　card2.setCardValue (222222222);

　　// array of objects

　　List cards = new ArrayList();

　　cards.add (card1);

　　cards.add (card2);

　　person.setCardList (cards);

　　String json = JSON.toJSON (person).toString ();

　　System.out.println (json);

　　//2.JSON string generated by JSON object

　　JSONObject jObject = new JSONObject ();

　　jObject.put ( "username", "xiejava");

　　jObject.put ( "sex", "man");

　　jObject.put ( "age", 38);

　　jObject.put ( "email", "xiejava @ ishareread.com ");

　　// array of objects packaged by JSONArray

　　JSONArray jArray = new JSONArray ();

　　jArray.addAll (cards);

　　jObject.put ( "cardList", jArray);

　　String json2 = jObject.toJSONString ();

　　System.out.println (json2);

　　// 3.JSON string generated by JSON object

　　JSONObject jObject2 = new JSONObject ();

　　jObject2.put ( "username", "xiejava");

　　jObject2.put ( "sex", "man");

　　jObject2.put ( "age", 38);

　　jObject2.put ( "email", "xiejava @ ishareread.com ");

　　// constructor JSON string

　　String cardjsonStr1 = "{" cardName ":" bankCard1 "," cardCode ":" 888888888 "," cardValue ": 99999999}";

　　String cardjsonStr2 = "{" cardName ":" bankCard2 "," cardCode ":" 999999999 "," cardValue ": 222222222}";

　　JSON.parseObject (cardjsonStr1);

　　JSONArray jArray2 = new JSONArray ();

　　// JSON string converted to JSON object is added to the JSONArray, [note must use JSON.Converting the parseObject () method of the object as JSON, or otherwise the string, the string when transferred into JSON will double quotes.]

　　jArray2.add (JSON.parseObject (cardjsonStr1));

　　jArray2.add (JSON.parseObject (cardjsonStr2));

　　jObject2.put ( "cardList", jArray2);

　　String json3 = jObject2.toJSONString ();

　　System.out.println (json3);

　　}

　　}