Json转换工具

我不是女神ヾ 2022-04-12 09:27 504阅读 0赞

jacksonJson是springMvc内置的json处理工具、其中有一个ObjectMapper处理json

User.java

public class User implements Serializable {
    
        private static final long serialVersionUID = 1L;
    
        private Long id;
    
        // 用户名
        private String userName;
    
        // 密码
        private String password;
    
        // 姓名
        private String name;
    
        // 年龄
        private Integer age;
    
        // 性别，1男性，2女性
        private Integer sex;
    
        // 出生日期
        private Date birthday;
    
        // 创建时间
        private Date created;
    
        // 更新时间
        private Date updated;

### 1、对象转Json ###

//对象转json
        @Test
        public void testJson() throws JsonProcessingException {
            ObjectMapper om = new ObjectMapper();
            User user = new User();
            user.setId(20L);
            user.setUserName("ssw");
            String json = om.writeValueAsString(user);
            System.out.println("json = " + json);
        }

![2018120223155360.png][]

### 2、Json转普通对象 ###

//json转对象
        @Test
        public void testJson() throws IOException {
            ObjectMapper om = new ObjectMapper();
            User user = new User();
            user.setId(20L);
            user.setUserName("ssw");
            //序列化
            String json = om.writeValueAsString(user);
    
            //反序列化
            User result = om.readValue(json,new TypeReference<User>(){});
    
            System.out.println("json = " + result);
        }

![20181202233300796.png][]

### 3、Json转集合 ###

//json转集合
        @Test
        public void testJson() throws IOException {
            ObjectMapper om = new ObjectMapper();
            User user = new User();
            user.setId(20L);
            user.setUserName("ssw");
            //序列化
            String jsonList = om.writeValueAsString(Arrays.asList(user,user));
    
            //反序列化
            List<User> result = om.readValue(jsonList,new TypeReference<List<User>>(){});
    
            System.out.println("json = " + result);
        }

![20181202234635347.png][]

![2018120223464767.png][]

### 4、Json转任意复杂类型 ###

//json转复杂类型
        @Test
        public void testJsons2() throws IOException {
            ObjectMapper om = new ObjectMapper();
            User user = new User();
            user.setId(20L);
            user.setUserName("ssw");
    
            Map<String,List<User>> maps = new HashMap<>();
            maps.put("users1",Arrays.asList(user,user,user));
            maps.put("users2",Arrays.asList(user,user,user,user));
            maps.put("users3",Arrays.asList(user,user,user,user,user));
            maps.put("users4",Arrays.asList(user,user));
            //序列化
            String jsonMap = om.writeValueAsString(maps);
            System.out.println("jsonMap = " + jsonMap);
    
            //反序列化
            Map<String,List<User>> userMaps = om.readValue(jsonMap,new TypeReference<Map<String,List<User>>>(){});
            System.out.println("userMaps = " + userMaps);
        }

###  ![20181203002547535.png][] ###

[2018120223155360.png]: /images/20220412/49247fc27783455f9d3b3e330e51cf78.png
[20181202233300796.png]: /images/20220412/b501cc1753b04cb9bd204798275185c9.png
[20181202234635347.png]: /images/20220412/ab60f91f5bb34d5096d5a96fe110e2ac.png
[2018120223464767.png]: /images/20220412/acf7c3bec3504a36a38c720dad4f471e.png
[20181203002547535.png]: /images/20220412/14eef76a1dc34029a26b40ae1761319a.png