JSON转对象，List，Map 转 JSON

1

import net.sf.json.JSONArray;

import net.sf.json.JSONObject;

public static void main(String[] args){
		
		User user = new User();
		user.setKeyid("0");
		user.setUsername("any");
		user.setPassword("123456");
		user.setSex("男");
		
		User user2 = new User();
		user2.setKeyid("1");
		user2.setUsername("any");
		user2.setPassword("123456");
		user2.setSex("男");
		
		//===========List转json==============//
		List<User> list = new ArrayList<User>();
		list.add(user);
		list.add(user2);
		
		JSONArray jobjectAry = JSONArray.fromObject(list);
		System.out.println(jobjectAry.toString());
		
		JSONObject jsonObj = new JSONObject();
		jsonObj.put("data", jobjectAry.toString());
		jsonObj.put("total", list.size());
		System.out.println(jsonObj.toString());
		
		//=============Map转json================//
		Map<String,String> map = new HashMap<String,String>();
		map.put("username", "小王");
		map.put("password", "男");
		
		JSONObject jsonObjMap = JSONObject.fromObject(map);
		System.out.println("Map:"+jsonObjMap.toString());
		
		
		//=============json转对象================//
		//注 map的Key必须写实体类相同
		User stu = (User)JSONObject.toBean(jsonObjMap, User.class);
		System.out.println("user"+stu.getUsername());
		
		//=============jsonArray转对象================//
        JSONArray array = JSONArray.fromObject(jobjectAry.toString());
        List<User> listUser = JSONArray.toList(array, User.class);// 过时方法
        System.out.println(list.get(0).getUsername());
	}