java 对象 json 集合 数组 互转

1、先定义一个类对象

package com.basics;

import com.alibaba.fastjson.JSONObject;

import java.util.List;
import java.util.Map;

/**
 * @author admin
 */
public class students {
    private Integer id;
    private String uname;
    private String hobby;
    private String dream;
    private List<Map<String,String>> info;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getUname() {
        return uname;
    }

    public void setUname(String uname) {
        this.uname = uname;
    }

    public String getHobby() {
        return hobby;
    }

    public void setHobby(String hobby) {
        this.hobby = hobby;
    }

    public String getDream() {
        return dream;
    }

    public void setDream(String dream) {
        this.dream = dream;
    }

    public List<Map<String, String>> getInfo() {
        return info;
    }

    public void setInfo(List<Map<String, String>> info) {
        this.info = info;
    }
    
    @Override
    public String toString(){
        return "{\"id\":\""+ id+ "\",\"uname\":\""+uname+"\",\"hobby\":\""+hobby+"\",\"dream\":\""+dream+"\",\"info\":"+ JSONObject.toJSONString(info) +"}";
    }
}

2、实例对象添加数据和转json

package com.basics;

import net.sf.json.JSONObject;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class objectMap {

    public static void main(String[] args){
        students std = new students();
        std.setId(123456);
        std.setUname("ouba");
        std.setHobby("rap");
        std.setDream("miss");
        List<Map<String,String>> info = new ArrayList<Map<String,String>>();
        Map<String,String> m = new HashMap<String,String>();
        m.put("名字1","欧巴");m.put("name2","哥哥");
        info.add(m);

        std.setInfo(info);

        System.out.println(std.toString());
        //对象转json
//        JSONObject json = JSONObject.parseObject(std.toString());
//        //List<String> line = (List<String>) json.get("info");
//        JSONArray line = (JSONArray) json.get("info");
//        System.out.println(line.get(1));
        JSONObject js = JSONObject.fromObject(std);
        String st = js.toString();
        System.out.println(st);
    }
}

注意，使用JSONObject 需要导入json-lib包，下载地址：链接: https://pan.baidu.com/s/1_TJqAvrth8yO2p-a-N33JA 提取码: q182 复制这段内容后打开百度网盘手机App，操作更方便哦