Hibernate的基于主键的one-to-one

一 示例

基于主键一对一(Person - IdCard)

IdCard的映射文件

<id name="id">    <generator class="foreign">    <param name="property">person</param>    </generator><id><one-to-one name="person" constrained="true"/>

[没有constraned true将不会生成外键约束]

Person映射文件

<one-to-one name="idCard" />

二 图解

三 代码

1 IdCard

package com.hsp.domain;import java.util.Date;public class IdCard implements java.io.Serializable {        private static final long serialVersionUID = 1L;        private Integer id;        private Date validateDte;        private Person person;        public Integer getId() {                return id;        }        public void setId(Integer id) {                this.id = id;        }        public Date getValidateDte() {                return validateDte;        }        public void setValidateDte(Date validateDte) {                this.validateDte = validateDte;        }        public Person getPerson() {                return person;        }        public void setPerson(Person person) {                this.person = person;        }}

2 Person

package com.hsp.domain;public class Person implements java.io.Serializable {        private static final long serialVersionUID = 1L;        private Integer id;        private String name;        private IdCard idCard;        public Integer getId() {                return id;        }        public void setId(Integer id) {                this.id = id;        }        public String getName() {                return name;        }        public void setName(String name) {                this.name = name;        }        public IdCard getIdCard() {                return idCard;        }        public void setIdCard(IdCard idCard) {                this.idCard = idCard;        }}

3 IdCard.hbm.xml

<?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.hsp.domain"><class name="IdCard" table="idCard"><!-- 因为我们这里讲的是基于主键的one-to-one, 所以我们使用外键策略 --> <id name="id" type="java.lang.Integer"><generator class="foreign"><param name="property">person</param></generator></id><property name="validateDte" type="java.util.Date"><column name="validateDte"/></property><!-- 这里配置IdCard和person属性是一对一的关系 --><one-to-one name="person" constrained="true"/></class></hibernate-mapping>

4 Person.hbm.xml

<?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.hsp.domain"><class name="Person" table="person"><id name="id" type="java.lang.Integer"><!-- 这里我们手动分配id --><generator class="assigned"/></id><property name="name" type="java.lang.String"><column name="name" length="128"/></property><!-- 这里配置person和idcard属性是一对一的关系 --><one-to-one name="idCard"/></class></hibernate-mapping>

四 测试代码

package com.hsp.view;import java.util.Date;import java.util.HashSet;import java.util.Set;import org.hibernate.Hibernate;import org.hibernate.Session;import org.hibernate.Transaction;import com.hsp.domain.IdCard;import com.hsp.domain.Person;import com.hsp.util.HibernateUtil;public class TestMain {    /**     * @param args     */    public static void main(String[] args) {        //添加一组Person/idcard        Session s=null;        Transaction tx=null;        try {            //我们使用基础模板来讲解.            s=HibernateUtil.getCurrentSession();            tx=s.beginTransaction();            Person p1=new Person();            p1.setId(1234);            p1.setName("顺平");            IdCard idCard=new IdCard();            idCard.setId(1900);            idCard.setValidateDte(new Date());            idCard.setPerson(p1);//表示idCard对象是属于p1这个对象.            s.save(p1);//先保存人            s.save(idCard);            tx.commit();        } catch (Exception e) {            e.printStackTrace();            if(tx!=null){                tx.rollback();            }        }finally{            if(s!=null && s.isOpen()){                s.close();            }        }        }}

五 测试结果

生成两张表的结构如下：

CREATE TABLE `idcard` (  `id` int(11) NOT NULL,  `validateDte` datetime DEFAULT NULL,  PRIMARY KEY (`id`),  KEY `FKB8CDF6CB2A59F864` (`id`),  CONSTRAINT `FKB8CDF6CB2A59F864` FOREIGN KEY (`id`) REFERENCES `person` (`id`)) ENGINE=InnoDB DEFAULT CHARSET=utf8;CREATE TABLE `person` (  `id` int(11) NOT NULL,  `name` varchar(128) DEFAULT NULL,  PRIMARY KEY (`id`)) ENGINE=InnoDB DEFAULT CHARSET=utf8;