FastJson

fastjson是阿里巴巴的开源JSON解析库，它可以解析JSON格式的字符串，支持将Java Bean序列化为JSON字符串，也可以从JSON字符串反序列化到JavaBean。

package apitest;

import java.util.HashMap;
import java.util.Map;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.serializer.SerializerFeature;
import com.github.checkpoint.JsonPath;

import test.User;

public class TestTest {
    public static void main(String[] args) {
        //对象转json
        User user =new User(1,"zhangsan","男","生日","地址");
        //SerializerFeature对数据进行一些定制  常用的有格式、空的时候展示、单引号等等
        String jsonString = JSON.toJSONString(user,SerializerFeature.PrettyFormat, 
                SerializerFeature.WriteNullStringAsEmpty, SerializerFeature.UseSingleQuotes);
        System.out.println(jsonString);
        //json转对象 
        User user1 =JSON.parseObject(jsonString,User.class);
        System.out.println(user1);
        //json转对象map
        Map map=JSON.parseObject(jsonString,HashMap.class);
        System.out.println(map);
        //map转json
        String jsonString2=JSON.toJSONString(map);
        System.out.println(jsonString2);

    }

}