Java中的对象与Json字符串互转

Java中的对象与Json字符串互转

• 对象、List、Map转Json字符串：JSONObject.toJSONString（）；

• Json字符串转对象：JSONObject.parseObject(userStr,XXX.class)；

• Json字符串转List：JSONArray.parseArray(arrayStr,XXX.class)；

• Json字符串转Map：JSONObject.parseObject(mapStr,Map.class)；

User类

package com.serialization;

import lombok.Data;
import lombok.ToString;

@Data
@ToString
public class User {
    /**
     * 用户ID
     */
    private String userId;
    /**
     * 用户名称
     */
    private String userName;
    /**
     * 用户年龄
     */
    private Integer age;
}

MainApp类

public class MainApp {
    public static void main(String[] args) {
        User user = new User();
        user.setUserId("1001");
        user.setUserName("YoYo");
        user.setAge(1000);
        //对象转Json字符传
        String userJson=JSONObject.toJSONString(user);
        System.out.println("Object to Json: " + userJson);

        //List转Json字符串
        List<User> list=new ArrayList<>();
        list.add(user);
        String userListJson= JSONObject.toJSONString(list);
        System.out.println("List to Json: "+userListJson);

        //Map转Json字符串
        Map<String,Object> map=new HashMap<>();
        map.put("name","YOYO");
        map.put("type","CAR");
        String mapJson=JSONObject.toJSONString(map);
        System.out.println("Map to Json: "+mapJson);

        String userStr="{"age":1000,"userId":"1001","userName":"YoYo"}";
        //对象Json字符串转对象
        User user1=JSONObject.parseObject(userStr,User.class);
        System.out.println("Json(Object) to Object: "+user1);

        //List Json字符串转List
        String arrayStr="[{"age":1000,"userId":"1001","userName":"YoYo"}]";
        List<User> list1= JSONArray.parseArray(arrayStr,User.class);
        System.out.println("Json(List) to List: "+list1);

        //Map Json字符串转Map
        String mapStr="{"name":"YOYO","type":"CAR"}";
        Map<String,String>map1=JSONObject.parseObject(mapStr,Map.class);
        System.out.println("Json(Map) to List: "+map1);
    }
}

执行结果

Object to Json: {"age":1000,"userId":"1001","userName":"YoYo"}
List to Json: [{"age":1000,"userId":"1001","userName":"YoYo"}]
Map to Json: {"name":"YOYO","type":"CAR"}
Json(Object) to Object: User(userId=1001, userName=YoYo, age=1000)
Json(List) to List: [User(userId=1001, userName=YoYo, age=1000)]
Json(Map) to List: {name=YOYO, type=CAR}