如何将 LocalDate 作为日期类型持久化到 Hibernate [英] How to persist LocalDate into Hibernate as a Date type

问题描述

我想将 LocalDate 作为 Date 类型保存到 Hibernate 中，但即使在 Hibernate 文档中我也找不到它.我试过一次，但它存储为 blob 类型.

I'd like to persist LocalDate into Hibernate as a Date type but I can't find it even in the Hibernate documentation. I've tried once but it is stored as blob type.

这是我的票务实体:

  <?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" 
         "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >
        <hibernate-mapping package="com.clustertech.entity">

   <class name="Ticket"  table="ticket">
    <id name="id" type="int" column="id">
        <generator class="native" />
    </id>
    <property name="date" column="tb_date" type="date"  length="35"/> 
    <property name="topic" column="tb_topic" type="string" length="35"/>
    <property name="subject" column="tb_subject" type="string" length="35"/>
    <property name="status" column="tb_status" type="string" length="35"/>
    <property name="message" column="tb_message" type="string"     length="255"/>

    <many-to-one name="person" column="person_id"/>

      </class>
  </hibernate-mapping>

这是我的班级实体:

public class Ticket implements Comparable<Ticket> {

   private int id;
   private LocalDate date;
   private String topic;
   private String Subject;
   private String message;
   private String status;
   private Person person;
}

它具有作为普通 POJO 类的 getter 和 setter.我在其他网站上看到过一种方法，但他们正在使用注释.我想要类似的东西，但我不使用注释只是普通的 POJO 类和 hbm.xml 文件.我很确定我必须创建另一个类才能将 LocalDate 转换为 Date 但我不知道如何将该类与我的实体连接起来.

It has getters and setters as a normal POJO class. I have seen in other websites one way to do that but they are using anotations. I would like something similar but I am not using anotations just normal POJO class and hbm.xml files. I'm pretty sure I have to create another class in order to convert LocalDate into Date but I don't know how to connect that class with my entity.

推荐答案

你必须创建一个转换器:

You have to create a converter:

@Converter
public class MyConverter implements AttributeConverter<LocalDate, Date> {

    @Override
    public Date convertToDatabaseColumn(LocalDate localDate) {
        if(localDate == null){
            return null;
        }

        return Date.valueOf(localDate);
    }

    @Override
    public LocalDate convertToEntityAttribute(Date date) {
        if(date == null){
            return null;
        }

        return date.toLocalDate();
    }
}

然后在您的 hbm.xml 文件中，您将转换器添加为该属性的类型:

Then in your hbm.xml file you add you converter as a type of that property:

<property name="date" column="tb_date" type="date"/>
<convert converter="com.mypkg.MyConverter" attribute-name="date"/>

这篇关于如何将 LocalDate 作为日期类型持久化到 Hibernate的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！