SpringBoot中Jackson日期格式化技巧分享_Java教程

Jackson 日期格式化技巧

使用 Spring Boot 时，需要使用 Jackson 处理一些 Java Time API 类型的 JSON 序列化问题，在处理一些类的字段时，可以通过直接在属性上加注解的方式来指定其格式化样式。但是，昨天同事遇到一个格式化 Map 数据的问题，这样就不能通过加注解来解决格式化样式的问题了。

在网上各种搜索，各种尝试后，终于解决了这个问题，记录一下，以备不时之需。

闲言少叙，直接上代码：

				?

									package com.diguage.demo.config;

									import com.fasterxml.jackson.databind.ObjectMapper;

									import com.fasterxml.jackson.databind.util.StdDateFormat;

									import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;

									import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateDeserializer;

									import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateTimeDeserializer;

									import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateSerializer;

									import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateTimeSerializer;

									import org.springframework.context.annotation.Bean;

									import org.springframework.context.annotation.Configuration;

									import org.springframework.context.annotation.Primary;

									import java.text.DateFormat;

									import java.text.SimpleDateFormat;

									import java.time.LocalDate;

									import java.time.LocalDateTime;

									import static com.fasterxml.jackson.databind.SerializationFeature.*;

									import static java.time.format.DateTimeFormatter.ofPattern;

									/<strong>

									 * 配置类

									 *

									 * @author D瓜哥 · <a href="https://www.diguage.com/" rel="external nofollow"  rel="external nofollow"  target="_blank" >https://www.diguage.com</a>

									 */

									@Configuration

									public class Config {

									    /</strong>

									     * 创建 ObjectMapper 对象，配置日期格式化

									     *

									     * @author D瓜哥 · <a href="https://www.diguage.com/" rel="external nofollow"  rel="external nofollow"  target="_blank" >https://www.diguage.com</a>

									     */

									    @Bean

									    @Primary

									    public ObjectMapper objectMapper() {

									        ObjectMapper mapper = new ObjectMapper();

									        String dateTimepattern = "yyyy-MM-dd HH:mm:ss";

									        String datePattern = "yyyy-MM-dd";

									        DateFormat dateFormat = new SimpleDateFormat(dateTimepattern);

									        mapper.setDateFormat(dateFormat);

									        mapper.configure(WRITE_DATES_AS_TIMESTAMPS, false);

									        mapper.setDateFormat(new StdDateFormat().withColonInTimeZone(true));

									        JavaTimeModule javaTimeModule = new JavaTimeModule();

									        javaTimeModule.addDeserializer(LocalDate.class,

									                new LocalDateDeserializer(ofPattern(datePattern)));

									        javaTimeModule.addSerializer(LocalDate.class,

									                new LocalDateSerializer(ofPattern(datePattern)));

									        javaTimeModule.addDeserializer(LocalDateTime.class,

									                new LocalDateTimeDeserializer(ofPattern(dateTimepattern)));

									        javaTimeModule.addSerializer(LocalDateTime.class,

									                new LocalDateTimeSerializer(ofPattern(dateTimepattern)));

									        mapper.registerModule(javaTimeModule);

									        return mapper;

									    }

									}

后续问题

不知道通过这种方式指定日期格式化样式后，在处理一些打格式化样式注解的字段时，会有什么样的表现？有机会测试一下。

补充：Jackson 统一配置日期转换格式

方式一:配置文件yml中配置

				?

									spring:

									    jackson:

									        default-property-inclusion: ALWAYS

									        time-zone: GMT+8

									        date-format: yyyy-MM-dd HH:mm:ss

这样序列化后，Date类型会被格式化成配置中的格式。

方式二:配置类中配置创建JacksonConfig.java

				?

									@Configuration

									public class JacksonConfig {

									    @Bean

									    @Order(Ordered.HIGHEST_PRECEDENCE)

									    public Jackson2ObjectMapperBuilderCustomizer customJackson() {

									        return new Jackson2ObjectMapperBuilderCustomizer() {

									            @Override

									            public void customize(Jackson2ObjectMapperBuilder builder) {

									                builder.serializerByType(LocalDateTime.class,

									                        new LocalDateTimeSerializer(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));

									                builder.serializerByType(LocalDate.class,

									                        new LocalDateSerializer(DateTimeFormatter.ofPattern("yyyy-MM-dd")));

									                builder.serializerByType(LocalTime.class,

									                        new LocalTimeSerializer(DateTimeFormatter.ofPattern("HH:mm:ss")));

									                builder.deserializerByType(LocalDateTime.class,

									                        new LocalDateTimeDeserializer(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));

									                builder.deserializerByType(LocalDate.class,

									                        new LocalDateDeserializer(DateTimeFormatter.ofPattern("yyyy-MM-dd")));

									                builder.deserializerByType(LocalTime.class,

									                        new LocalTimeDeserializer(DateTimeFormatter.ofPattern("HH:mm:ss")));

									                builder.serializationInclusion(JsonInclude.Include.NON_NULL);

									                builder.failOnUnknownProperties(false);

									                builder.featuresToDisable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);

									            }

									        };

									    }

									}