json转Map，json转List＜实体类＞

实例代码：

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import lombok.Data;

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

@Data
public class User {
    /**
     * 序号
     */
    private Integer id;
    /**
     * 用户名
     */
    private String username;
    /**
     * 密码
     */
    private String password;

    public static void main(String[] args) {
        String result = "{\"id\":1,\"username\":\"张三\",\"password\":\"zhangsan\"}";
        String result1 = "[{\"id\":1,\"username\":\"张三\",\"password\":\"zhangsan\"},{\"id\":1,\"username\":\"李四\",\"password\":\"lisi\"}]";
        
        Map<String, Object> resultMap = JSON.parseObject(result);
        System.out.println(resultMap.get("username"));

        List<User> list = JSONObject.parseArray(result1, User.class);
        System.out.println(list.get(0).getUsername());
        System.out.println(list.get(1).getUsername());
    }
}

运行结果：