fastjson简单使用

1.依赖

创建maven项目，引入依赖

        <!-- fastjson-->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
        </dependency>

2.简单使用

2.1 简单Java类转json字符串

String UserJson = JSON.toJSONString(user);

2.2 List<Object>转json字符串

        User user1 = new User("zhangsan", "123123");
        User user2 = new User("lisi", "321321");
        List<User> users = new ArrayList<User>();
        users.add(user1);
        users.add(user2);
        String ListUserJson = JSON.toJSONString(users);            

2.3 复杂Java类转json字符串

　　　　　UserGroup userGroup = new UserGroup("userGroup", users);
        String userGroupJson = JSON.toJSONString(userGroup);

2.4 json字符串转Java对象

　　　　　String jsonStr1 = "{'password':'123456','username':'dmego'}";
　　　　　User user = JSON.parseObject(jsonStr1, User.class);

2.5 json字符串转List<Object>对象

　　　　　String jsonStr2 = "[{'password':'123123','username':'zhangsan'},{'password':'321321','username':'lisi'}]";
        List<User> users = JSON.parseArray(jsonStr2, User.class);

2.6 json字符串转复杂Java对象

　　　　　String jsonStr3 = "{'name':'userGroup','users':[{'password':'123123','username':'zhangsan'},{'password':'321321','username':'lisi'}]}";
        UserGroup userGroup = JSON.parseObject(jsonStr3, UserGroup.class);

2.7 map转对象

　　　　　String mapString = JSONObject.toJSONString(map);
        Hospital hospital = JSONObject.parseObject(mapString, Hospital.class);