Springboot 全局时间格式化

背景

Springboot 全局时间格式化，前后端日期类型参数格式化。

解决

方式大部分四种

1 @JsonFormat

字段加上 @JsonFormat 注解后，LocalDateTime 和 Date 时间格式化成功。需要在每个字段上添加该注解，不算全局时间格式化。不推荐

import com.fasterxml.jackson.annotation.JsonFormat;

@Data
public class TestDTO{

    @JsonFormat(locale = "zh", timezone = "GMT+8", pattern = "yyyy-MM-dd HH:mm:ss")
    private LocalDateTime createTime;

    @JsonFormat(locale = "zh", timezone = "GMT+8", pattern = "yyyy-MM-dd HH:mm:ss")
    private Date updateTime;
}

2 配置文件配置参数

这种方式只对 Date 类型生效。不推荐

spring:
  jackson:
    date-format: yyyy-MM-dd HH:mm:ss
    time-zone: GMT+8

3 @JsonComponent

自定义Configuration类。
Date、LocalDateTime类型日期均生效
推荐

/**
 * 全局日期格式化 如果某个字段不使用该格式
 * 依旧可以使用 @JsonFormat(locale = "zh", timezone = "GMT+8", pattern = "yyyy-MM-dd") 修改某个字段的格式化信息，且@JsonFormat优先级高于@JsonComponent配置的格式类型
 */
@JsonComponent
@Configuration
public class DateFormatConfig {

    @Value("${spring.jackson.date-format:yyyy-MM-dd HH:mm:ss}")
    private String pattern;

    /**
     * 类型全局时间格式化
     */
    @Bean
    public Jackson2ObjectMapperBuilderCustomizer jackson2ObjectMapperBuilder() {
        return builder -> {
            TimeZone tz = TimeZone.getTimeZone("GMT+8");
            DateFormat df = new SimpleDateFormat(pattern);
            df.setTimeZone(tz);
            builder.failOnEmptyBeans(false)
                    .failOnUnknownProperties(false)
                    .featuresToDisable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS)
                    .dateFormat(df);
        };
    }

    /**
     * 类型全局时间格式化
     */
    @Bean
    public LocalDateTimeSerializer localDateTimeDeserializer() {
        return new LocalDateTimeSerializer(DateTimeFormatter.ofPattern(pattern));
    }

    @Bean
    public Jackson2ObjectMapperBuilderCustomizer jackson2ObjectMapperBuilderCustomizer() {
        return builder -> builder.serializerByType(LocalDateTime.class, localDateTimeDeserializer());
    }
}

4 @Configuration

这种全局配置的实现方式与上边的效果是一样的。
注意：在使用此种配置后，字段手动配置@JsonFormat 注解将不再生效。
不推荐

@Configuration
public class DateFormatConfig2 {

    @Value("${spring.jackson.date-format:yyyy-MM-dd HH:mm:ss}")
    private String pattern;

    public static DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

    @Bean
    @Primary
    public ObjectMapper serializingObjectMapper() {
        ObjectMapper objectMapper = new ObjectMapper();
        JavaTimeModule javaTimeModule = new JavaTimeModule();
        javaTimeModule.addSerializer(LocalDateTime.class, new LocalDateTimeSerializer());
        javaTimeModule.addDeserializer(LocalDateTime.class, new LocalDateTimeDeserializer());
        objectMapper.registerModule(javaTimeModule);
        return objectMapper;
    }

    /**
     * 时间类型装换
     */
    @Component
    public class DateSerializer extends JsonSerializer<Date> {
        @Override
        public void serialize(Date date, JsonGenerator gen, SerializerProvider provider) throws IOException {
            String formattedDate = dateFormat.format(date);
            gen.writeString(formattedDate);
        }
    }

    /**
     * 时间类型装换
     */
    @Component
    public class DateDeserializer extends JsonDeserializer<Date> {

        @Override
        public Date deserialize(JsonParser jsonParser, DeserializationContext deserializationContext) throws IOException {
            try {
                return dateFormat.parse(jsonParser.getValueAsString());
            } catch (ParseException e) {
                throw new RuntimeException("Could not parse date", e);
            }
        }
    }

    /**
     * 时间类型装换
     */
    public class LocalDateTimeSerializer extends JsonSerializer<LocalDateTime> {
        @Override
        public void serialize(LocalDateTime value, JsonGenerator gen, SerializerProvider serializers) throws IOException {
            gen.writeString(value.format(DateTimeFormatter.ofPattern(pattern)));
        }
    }

    /**
     * 时间类型装换
     */
    public class LocalDateTimeDeserializer extends JsonDeserializer<LocalDateTime> {
        @Override
        public LocalDateTime deserialize(JsonParser p, DeserializationContext deserializationContext) throws IOException {
            return LocalDateTime.parse(p.getValueAsString(), DateTimeFormatter.ofPattern(pattern));
        }
    }
}

参考

• https://developer.aliyun.com/article/771395