Spring Boot为Jackson配置日期时间格式

package com.tencent.web;

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 lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.autoconfigure.jackson.Jackson2ObjectMapperBuilderCustomizer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.convert.converter.Converter;

import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;

/**
 * 配置日期时间格式转换器.
 *
 * @author tenmao
 */
@Slf4j
@Configuration
public class LocalDateTimeSerializerConfig {
    
    /**
     * 使用这个配置，就可以兼容jackson对Date转换的格式
     */
    @Value("${spring.jackson.date-format}")
    private String pattern;

    /**
     * 定义日期时间格式.
     */
    @Bean
    public DateTimeFormatter dateTimeFormatter() {
        return DateTimeFormatter.ofPattern(pattern);
    }

    /**
     * 从日期时间格式中解析出日期格式，这样就不用再单独配置日期格式了.
     */
    @Bean
    public DateTimeFormatter dateFormatter() {
        int begin = pattern.indexOf("y");
        int end = pattern.lastIndexOf("d");
        String dateFormatter = pattern.substring(begin, end + 1);
        log.info("datetime formatter: {}, date formatter: {}", pattern, dateFormatter);
        return DateTimeFormatter.ofPattern(dateFormatter);
    }

    /**
     * 为Jackson配置LocalDateTime和LocalDate的转换规则(body).
     */
    @Bean
    public Jackson2ObjectMapperBuilderCustomizer jackson2ObjectMapperBuilderCustomizer() {
        return builder -> {
            builder.serializerByType(LocalDateTime.class, new LocalDateTimeSerializer(dateTimeFormatter()));
            builder.deserializerByType(LocalDateTime.class, new LocalDateTimeDeserializer(dateTimeFormatter()));

            builder.serializerByType(LocalDate.class, new LocalDateSerializer(dateFormatter()));
            builder.deserializerByType(LocalDate.class, new LocalDateDeserializer(dateFormatter()));
        };
    }

    /**
     * 为RequestParameter配置日期时间格式转换器.
     */
    @Bean
    public Converter<String, LocalDateTime> localDateTimeConvert() {
        return new Converter<String, LocalDateTime>() {
            @Override
            public LocalDateTime convert(String source) {
                return LocalDateTime.parse(source, dateTimeFormatter());
            }
        };
    }

    /**
     * 为RequestParameter配置日期格式转换器.
     */
    @Bean
    public Converter<String, LocalDate> localDateConvert() {
        return new Converter<String, LocalDate>() {
            @Override
            public LocalDate convert(String source) {
                return LocalDate.parse(source, dateFormatter());
            }
        };
    }
}