hibernate onetoone 双向主键映射

主键关联，就是两个一对一的实体共用相同的id
而唯一外键映射：是通过manytoone unique的方法 增加一个外键字段完成的

onetoone不影响存储 只影响加载

package hibernate.belle;

public class IDcard {
private String no;
private String id;
private Person person;

public String getId() {
    return id;
}

public void setId(String id) {
    this.id = id;
}



public String getNo() {
    return no;
}

public void setNo(String no) {
    this.no = no;
}

public Person getPerson() {
    return person;
}

public void setPerson(Person person) {
    this.person = person;
}

}

package hibernate.belle;

public class Person {
    private String id;
    private String name;

    private IDcard idcard;

    public String getId() {
        return id;
    }

    public void setId(String 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;
    }
}

配置文件：

<?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 >
 <class name="hibernate.belle.IDcard"  table="t_idcard"> 
          <id name="id" >
              <generator class="native"/> 
          </id>
          <property name="no"/>
          <one-to-one name="person"></one-to-one>


</class>
</hibernate-mapping>

<?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 >
 <class name="hibernate.belle.Person"  table="t_person"> 
          <id name="id">
              <generator class="foreign"> 
              <param name="property">idcard</param>
              </generator>
          </id>
          <property name="name"/>


          <one-to-one name="idcard"  constrained="true" />  
</class>
</hibernate-mapping>

测试：

import org.hibernate.Session;

import hibernate.belle.HibernateUtils;
import hibernate.belle.IDcard;
import hibernate.belle.Person;
import junit.framework.TestCase;

public class OneToOneTest extends TestCase{


      public void test2()
      {
          Session session=null;
          try{
              session=HibernateUtils.getSession();
              session.beginTransaction();

              IDcard idcard=new IDcard();
              idcard.setNo("1112");

              Person person=new Person();
              person.setName("Belle");
              person.setIdcard(idcard);


              session.save(person);//双向的时候还是靠person维护 你用idcard.setperson save(idcard)  hibernate还是不知道这个关系的  所以还是得要按这样存


              /// System.out.println("idd's name is  "+idd.getPerson().getName());
              session.beginTransaction().commit();


          }catch(Exception e)
          {
              e.printStackTrace();
              session.beginTransaction().rollback();
          }finally
          {
              HibernateUtils.closeSession(session);
          }

      }

      public void testload()
      {
          Session session=null;
          try{
              session= HibernateUtils.getSession();
              session.beginTransaction();
             IDcard idd=(IDcard)session.load(IDcard.class,"3");

             System.out.println("idd's name is  "+idd.getPerson().getName());

              session.beginTransaction().commit();

          }catch(Exception e)
          {
              e.printStackTrace();
              session.beginTransaction().rollback();
          }finally{
              HibernateUtils.closeSession(session);
          }
      }

}