java json data transfer

The background interface sends data to the Android client through a json object, and uses json to parse the received data.
packages that need to be imported

import net.sf.json.JSONArray;
import net.sf.json.JSONObject;

Send data
in a class on the server side, generate a json string

//声明一个Hash对象并添加数据
Map params =  new HashMap();

params.put("username", username);
params.put("user_json", user);

//声明JSONArray对象并输入JSON字符串
JSONArray array = JSONArray.fromObject(params);
put.println(array.toString());

 List<> list = new ArrayList<>();      
 list.add("姓名",1);
 list.add("年龄",2);      
 JSONArray jsonarray = JSONArray.fromObject(list);

Analytical data

//根据接收到的JSON字符串来解析字符串中所包含的数据和数据对象

//接收到的JSON字符串
String result = "[{\"user_desc\": \"desc\", \"user_json\": {\"user_name\": \"name\", \"user_age\": \"age\"}}]";

//String字符串生成JSON对象
JSONArray resultArray = new JSONArray(result);
JSONObject resultObj = resultArray.optJSONObject(0);

//获取数据对象
JSONObject user = resultObj.getJSONObject("user_json");
String name= user.getString("user_name");