JSON的入门介绍学习

港控/mmm° 2022-12-18 12:56 140阅读 0赞

JSON封装数据的几种方式
    package com.feture.test;
    import com.feture.po.Game;
    import net.sf.json.JSONArray;
    import net.sf.json.JSONObject;
    import net.sf.json.JsonConfig;
    
    import java.util.*;
    
    public class TestJson {
        
        public static void main(String[] args) {
        
            /*
            *   JavaScript Object Notation
            *   JSON
            *   一种轻量级的数据交换格式，2004年诞生，2006年加入
            *   ajax技术体系，用来取代xml封装批量数据，可以在Java服务器端
            *   和Js端同时使用
            *   格式:
            *       1){key1:value1,key2:value2,keyN:valueN}
            *       key:字符串
            *       value:
                *       字符串
                *       八种基本数据类型
                *       null
                *       数组
                *       json
                *
                *   2)[value1,value2,value3,valueN]
                *
                *   value:
                *        字符串
                 *       八种基本数据类型
                 *       null
                 *       数组
                 *       json
                *
    
                封装方式1:可以封装任意数据类型，封装之后呈现第一种
                格式的json
            * */
            String str = "etoak";
            String[] strAr = {
        "济南","青岛","淄博"};
            boolean flag = true;
            int i = 100;
    
            JSONObject jo1 = new JSONObject();
            jo1.put("key1",str);
            jo1.put("key2",strAr);
            jo1.put("key3",flag);
            jo1.put("key4",i);
            //{"key1":"etoak","key2":["济南","青岛","淄博"],"key3":true,"key4":100}
            System.out.println(jo1);
    
            JSONObject jo2 = new JSONObject();
            jo2.put("myGame",new Game(1,"只狼","AVG"));
            //{"myGame":{"name":"只狼","id":1,"type":"AVG"}}
            System.out.println(jo2);
    
            /*
            *   封装方式2:可以封装自定义数据类型和Map
            *   封装之后呈现第一种格式的json
            * */
    
            Map<Integer,String> map = new HashMap<Integer,String>();
            map.put(1,"Javascript");
            map.put(2,"jQuery");
            map.put(3,"VUE");
            map.put(4,"Angular");
            map.put(5,"React");
    
            JSONObject js1 = JSONObject.fromObject(map);
            //{"1":"Javascript","2":"jQuery","3":"VUE","4":"Angular","5":"React"}
            System.out.println(js1);
    
            JSONObject js2 = JSONObject.fromObject(
            new Game(2,"dota自走棋","slg"));
            //{"name":"dota自走棋","id":2,"type":"slg"}
            System.out.println(js2);
    
            //对自定义数据类型中的属性进行有选择的封装
            JsonConfig jc = new JsonConfig();
            //设置不需要封装的字段名
            jc.setExcludes(new String[]{
        "id","type"});
            JSONObject js3 = JSONObject.fromObject(
            new Game(3,"王者荣耀","moba"),jc);
            //{"name":"王者荣耀"}
            System.out.println(js3);
    
            /*
            *   封装方式3:
            *       可以封装List Set 和 数组
            *       封装之后呈现格式2的json
            * */
            List<String> list = new ArrayList<String>();
            list.add("Iphone");
            list.add("Apple Watch");
            list.add("Air Pods");
            list.add("MacBook");
            list.add("Ipad");
            JSONArray ja1 = JSONArray.fromObject(list);
            //["Iphone","Apple Watch","Air Pods","MacBook","Ipad"]
            System.out.println(ja1);
            JSONArray ja2 = JSONArray.fromObject(strAr);
            //["济南","青岛","淄博"]
            System.out.println(ja2);
    
            Set<String> set = new HashSet<String>();
            set.add("Java");
            set.add("C");
            set.add("C++");
            set.add("Php");
            set.add("Swift");
            JSONArray ja3 = JSONArray.fromObject(set);
            //["Java","C++","C","Php","Swift"]
            System.out.println(ja3);
    
        }
    }