Spring Boot Java8 LocalDateTime日期序列化与反序列化 解决方案

网上绝大多数的解决方案都是没有用的！不要浪费时间！！！

使用场景

一）、DTO含有LocalDateTime字段时，可以将日期格式化，传输出去

二）、当后端实体对象的LocalDateTime字段需要接收前端传来的日期字符串，如2019-12-01，可以反序列化给日期字段

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LocalDateTime 反序列化器

不需要另外引入什么jsr310依赖，spring-boot-starter-web里面就包含有

<dependency>
    <groupId>com.fasterxml.jackson.datatypegroupId>
    <artifactId>jackson-datatype-jsr310artifactId>
    <version>2.9.10version>
    <scope>compilescope>
dependency>

<dependency>
    <groupId>cn.hutoolgroupId>
    <artifactId>hutool-coreartifactId>
    <version>4.5.2version>
dependency>

import cn.hutool.core.date.DateTime;
import cn.hutool.core.date.DateUtil;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JsonDeserializer;

import java.io.IOException;
import java.time.Instant;
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.util.Date;

/**
 * LocalDateTime 反序列化器
 * 

 * 说明：
 * 1. 借用hutool相关工具类
 *
 * @author MoCha
 * @date 2019/11/30
 */
public class LocalDateTimeDeserializer extends JsonDeserializer<LocalDateTime> {
    @Override
    public LocalDateTime deserialize(JsonParser parser, DeserializationContext context) throws IOException {
        String dateStr = parser.getText();
        DateTime dateTime;
        try {
            dateTime = DateUtil.parse(dateStr);
        } catch (Exception e) {
            dateTime = DateUtil.parseDateTime(dateStr.replaceAll("T", " "));
        }
        Date date = dateTime.toJdkDate();
        Instant instant = date.toInstant();
        ZoneId zoneId = ZoneId.systemDefault();
        return instant.atZone(zoneId).toLocalDateTime();
    }

    @Override
    public Class<?> handledType() {
        // 关键
        return LocalDateTime.class;
    }
}

LocalDateTime 日期适配器

import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateTimeSerializer;
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 java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;

/**
 * LocalDateTime 日期适配器
 *
 * @author MoCha
 * @date 2019/11/30
 */
@Configuration
public class LocalDateTimeConvertConfig {
    @Value("${spring.jackson.date-format:yyyy-MM-dd HH:mm:ss}")
    private String pattern;

    /**
     * 配置LocalDateTime 序列化器与反序列化器
     * 

     * 说明：
     * 1. 下面配置的new LocalDateTimeDeserializer()为我们定制的LocalDateTime反序列化器
     */
    @Bean
    public Jackson2ObjectMapperBuilderCustomizer jackson2ObjectMapperBuilderCustomizer() {
        return builder -> {
            builder.serializerByType(LocalDateTime.class, localDateTimeSerializer());
            builder.deserializerByType(LocalDateTime.class, new LocalDateTimeDeserializer());
        };
    }

    /**
     * LocalDateTime 序列化器
     */
    @Bean
    public LocalDateTimeSerializer localDateTimeSerializer() {
        return new LocalDateTimeSerializer(DateTimeFormatter.ofPattern(pattern));
    }
}