json-lib全部相关jar及例子

package com.Jtianlin.jsonTest; import java.util.ArrayList; import java.util.HashMap; import java.util.HashSet; import java.util.List; import java.util.Map; import java.util.Set; import net.sf.json.JSONArray; import net.sf.json.JSONObject; public class BeanToJson { public static void main(String[] args) { //由对象转换成json字符串，用JSONObject User user = new User(); user.setAddress("安徽"); user.setUsername("张三"); JSONObject jsonObject = JSONObject.fromObject(user); System.out.println(jsonObject); //打印结果：{"address":"安徽","username":"张三"} //由list转换成json字符串，用JSONArray List<User> list = new ArrayList<User>(); User user1 = new User(); user1.setAddress("山东"); user1.setUsername("李四"); User user2 = new User(); user2.setAddress("北京"); user2.setUsername("王五"); list.add(user1); list.add(user2); JSONArray jsonArray = JSONArray.fromObject(list); System.out.println(jsonArray); //打印结果：[{"address":"山东","username":"李四"},{"address":"北京","username":"王五"}] //下面方式错误，将list集合转换成json字符串必须使用jsonArray。 // JSONObject jsonObject2 = JSONObject.fromObject(list); // System.out.println(jsonObject2); //由map转换成json字符串，用jsonObject Map<String,User> map = new HashMap<String,User>(); map.put("user1", user1); map.put("user2", user2); JSONObject jsonObjectMap = JSONObject.fromObject(map); System.out.println(jsonObjectMap); //打印结果：{"user2":{"address":"北京","username":"王五"},"user1":{"address":"山东","username":"李四"}} //由set转换成json字符串，需要用JSONArray Set set = new HashSet(); set.add(user1); set.add(user2); JSONArray jsonArraySet = JSONArray.fromObject(set); System.out.println(jsonArraySet); //打印结果：[{"address":"北京","username":"王五"},{"address":"山东","username":"李四"}] } }