java spring boot返回json的写法

package com.example.demo2122;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import java.util.*;
@RestController
public class HelloControl {
    @GetMapping("/hello")
    public Map<Object, Object> hello(@RequestParam(value = "name", defaultValue = "World") String name) {
        List<Map<Object, Object>> list = new ArrayList<Map<Object, Object>>();
        Map<Object, Object> map1 = new HashMap<Object, Object>();
        map1.put("姓名1", "张三");
        map1.put("姓名2", "李四");
        map1.put("姓名3", "王五");
        list.add(map1);

        Map<Object, Object> map=this.commonajax(100,"查询成功",list);


        return map;
    }

    private Map<Object, Object> commonajax(Integer code,String msg,List<Map<Object, Object>> data){
        Map<Object, Object> map = new HashMap<Object, Object>();
        map.put("code", code);
        map.put("msg", "查询成功");
        map.put("data", data);
        return map;
    }
}