JSON

package com.hanqi.test;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;

import org.json.JSONException;

import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;

public class TestJSON {

	public static void main(String[] args) {
		// 测试JSON解析
		//1.从对象(集合)到JSON字符串
		User u1 = new User(999,"admin","123456");
		u1.setBirthday(new Date());//long型数值
		String ju1 = JSONObject.toJSONString(u1);
		
		System.out.println("ju1="+ju1);
		
		
		
		
		//集合
		List<User> lu = new ArrayList<User>();
		lu.add(new User(111,"User1","1111"));
		lu.add(new User(222,"User2","2222"));
		lu.add(new User(333,"User3","3333"));
		lu.add(new User(444,"User4","4444"));
		
		String jlu = JSONArray.toJSONString(lu);
		System.out.println("jlu="+jlu);
		
		
		//官方
		try {
			org.json.JSONArray ja = new org.json.JSONArray(jlu);
		org.json.JSONObject u3 =  ja.getJSONObject(0);
			System.out.println("u3="+u3.getInt("userID"));
			
		} catch (JSONException e1) {
			// TODO 自动生成的 catch 块
			e1.printStackTrace();
		}
		
		
		//2.从JSON字符串到对象或集合
		System.out.println("2.从JSON字符串到对象或集合.................");
		
		User u2 = (User)JSONObject.parseObject(ju1, User.class);
		System.out.println("u2="+u2);
		
		//字符创到 集合
				List<User> lu2 = JSONArray.parseArray(jlu, User.class);
				for(User u : lu2)
				{
					System.out.println(u);
				}
				
		
		
		//官方
		try {
			org.json.JSONObject jo =new org.json.JSONObject(ju1);
			int userid = jo.getInt("userID");
			System.out.println("userid="+userid);
			
			
		} catch (JSONException e) {
			// TODO 自动生成的 catch 块
			e.printStackTrace();
		}
		
	}

}

  

原文地址:https://www.cnblogs.com/liuyanzeng/p/6094845.html