1.String 转 Json

@Test
public void test(){String str = "{\"age\":\"24\",\"name\":\"hekliu\"}";  JSONObject jsonObject = JSONObject.parseObject(str);System.out.println("json对象是：" + jsonObject);Object object = jsonObject.get("name");System.out.println("name值是：" + object);
}

运行结果：json对象是：{"name":"hekliu","age":"24"} name值是：hekliu

2.Json 转 String

@Test
public void test(){String str = "{\"age\":\"24\",\"name\":\"hekliu\"}";JSONObject jsonObject = JSONObject.parseObject(str);//json对象转字符串String jsonString = jsonObject.toJSONString();System.out.println("json字符串是：" + jsonString);
}

运行结果：json字符串是：{"name":"hekliu","age":"24"}

3.String 转 Map

@Test
public void test(){String str = "{\"age\":\"24\",\"name\":\"hekliu\"}";JSONObject jsonObject = JSONObject.parseObject(str);//json对象转MapMap<String, Object> map = (Map<String, Object>)jsonObject;System.out.println("map对象是：" + map);Object object = map.get("age");System.out.println("age的值是" + object);
}

运行结果：map对象是：{"name":"hekliu","age":"24"}age的值是24

4.Map 转 String

@Test
public void test(){Map<String,Object> map = new HashMap<>();map.put("age", 24);map.put("name", "hekliu");String jsonString = JSON.toJSONString(map);System.out.println("json字符串是：" + jsonString);
}

运行结果：json字符串是：{"name":"hekliu","age":24}

5.Map 转 Json

@Test
public void test(){Map<String,Object> map = new HashMap<>();map.put("age", 24);map.put("name", "hekliu");JSONObject json = new JSONObject(map);System.out.println("Json对象是：" + json);
}

运行结果：Json对象是：{"name":"hekliu","age":24}

6.Json 转 Map

     见示例3

7.对象与字符串之间的互转

//将对象转换成为字符串
String str = JSON.toJSONString(infoDo);
//字符串转换成为对象
InfoDo infoDo = JSON.parseObject(strInfoDo, InfoDo.class);

8.对象集合与字符串之间的互转

//将对象集合转换成为字符串
String users = JSON.toJSONString(users);
//将字符串转换成为对象集合
List<User> userList = JSON.parseArray(userStr, User.class);