SpringBoot中默认的JSON解析方案日期格式化多种解决方案

川长思鸟来 2022-12-23 14:27 362阅读 0赞

# SpringBoot中默认的JSON解析方案 #

## 一、pom依赖 ##

# 在这边我们不需要去导入专门的json解析，因为在spring-boot-stater-web中含有spring-boot-stater-json依赖

<dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>

## 二、User实体 ##

# User实体来做测试返回，在User中加入了date类

/** * @Create_Author msfh * @Create_Date 2020-11-25 14:52:35 * @Description UserTest */
    public class User { 
        private Integer id;
        private String name;
        private Date birthday;
        private String address;
    
        @Override
        public String toString() { 
            return "User{" +
                    "id=" + id +
                    ", name='" + name + '\'' +
                    ", birthday=" + birthday +
                    ", address='" + address + '\'' +
                    '}';
        }
        /**set&get省略**/
    }

## 三、UserController控制器 ##

# 在这边我们就不连接数据库进行测试了，直接去循环添加一下假数据进行返回

/** * @Create_Author msfh * @Create_Date 2020-11-25 14:53:43 * @Description User控制层 */
    @RestController
    public class UserController { 
    
        @GetMapping("user")
        public List<User> getUsers(){ 
            ArrayList<User> users = new ArrayList<>();
            for (int i = 0; i < 10; i++) { 
                User user = new User();
                user.setId(i);
                user.setName("msfh-"+i);
                user.setAddress("msfh-"+i);
                user.setBirthday(new Date());
                users.add(user);
            }
            return users;
        }
    
    }

## 四、第一次测试 ##

# 以下是访问接口放回的结果

[{ "id":0,"name":"msfh-0","birthday":"2020-11-25T07:29:34.711+00:00","address":"msfh-0"},{ "id":1,"name":"msfh-1","birthday":"2020-11-25T07:29:34.711+00:00","address":"msfh-1"},{ "id":2,"name":"msfh-2","birthday":"2020-11-25T07:29:34.711+00:00","address":"msfh-2"},{ "id":3,"name":"msfh-3","birthday":"2020-11-25T07:29:34.711+00:00","address":"msfh-3"},{ "id":4,"name":"msfh-4","birthday":"2020-11-25T07:29:34.711+00:00","address":"msfh-4"},{ "id":5,"name":"msfh-5","birthday":"2020-11-25T07:29:34.711+00:00","address":"msfh-5"},{ "id":6,"name":"msfh-6","birthday":"2020-11-25T07:29:34.711+00:00","address":"msfh-6"},{ "id":7,"name":"msfh-7","birthday":"2020-11-25T07:29:34.711+00:00","address":"msfh-7"},{ "id":8,"name":"msfh-8","birthday":"2020-11-25T07:29:34.711+00:00","address":"msfh-8"},{ "id":9,"name":"msfh-9","birthday":"2020-11-25T07:29:34.711+00:00","address":"msfh-9"}]

# 这里我们可以看到我们的birthday属性的值是没有被格式话的，但是是被正常返回的
    # 因为SpringBoot帮我们配置了JacksonAutoConfiguration，所以我们这边是可以正常返回接口的
    # 根据JacksonAutoConfiguration里的代码我们是可以重写ObjectMapper去完成日期的代码格式化
    # 在我们了解到JacksonAutoConfiguration类时，我们首先了解到的是JacksonHttpMessageConvertersConfiguration
    # 在里面有MappingJackson2HttpMessageConverter，我们去重新定义这个我们也是可以解决的，但是就没有第一种方式比较简便
    # 在WebMvcConfig类中我会放上这两种方式的代码，但会注释第二种方式的代码

## 五、WebMvcConfig工具类 ##

/** * @Create_Author msfh * @Create_Date 2020-11-25 14:58:23 * @Description web控制器 */
    @Configuration
    public class WebMvcConfig { 
    
        //@Bean
        //MappingJackson2HttpMessageConverter mappingJackson2HttpMessageConverter(){ 
        // MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter();
        // ObjectMapper objectMapper = new ObjectMapper();
        // objectMapper.setDateFormat(new SimpleDateFormat("yyyy-MM-dd"));
        // converter.setObjectMapper(objectMapper);
        // return converter;
        //}
        @Bean
        ObjectMapper objectMapper(){ 
            ObjectMapper objectMapper = new ObjectMapper();
            objectMapper.setDateFormat(new SimpleDateFormat("yyyy/MM/dd"));
            return objectMapper;
        }
    
    }

# 重新运行项目我们这次的返回结果如下：

[{ "id":0,"name":"msfh-0","birthday":"2020/11/25","address":"msfh-0"},{ "id":1,"name":"msfh-1","birthday":"2020/11/25","address":"msfh-1"},{ "id":2,"name":"msfh-2","birthday":"2020/11/25","address":"msfh-2"},{ "id":3,"name":"msfh-3","birthday":"2020/11/25","address":"msfh-3"},{ "id":4,"name":"msfh-4","birthday":"2020/11/25","address":"msfh-4"},{ "id":5,"name":"msfh-5","birthday":"2020/11/25","address":"msfh-5"},{ "id":6,"name":"msfh-6","birthday":"2020/11/25","address":"msfh-6"},{ "id":7,"name":"msfh-7","birthday":"2020/11/25","address":"msfh-7"},{ "id":8,"name":"msfh-8","birthday":"2020/11/25","address":"msfh-8"},{ "id":9,"name":"msfh-9","birthday":"2020/11/25","address":"msfh-9"}]

# 这次我们可以看到我们这次的代码被格式化了

## 六、配置properties ##

# 我们通过配置application.properties配置文件也是可以实现日期格式化的

1、application.yml

spring:
      jackson:
        date-format: yyyy-MM-dd

2、application.properties

spring.jackson.date-format=yyyy-MM-dd

# 我们通过多种方式都可以实现日期的格式化
    # 但是追求本源都是修改配置文件，SpringBoot中的思想就是，你有或者你配置了就用你的，你没有或者你没配置那你就用我的