Hibernate xml配置方法 之 联合主键

StudentPK类，存放Student的联合主键，必须实现java.io.Serializable接口(为了序列化扩充移植)，必须重写equals跟hashCode方法（为了确保唯一性）

public class StudentPK implements java.io.Serializable{
private int id;
private String name;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}

@Override
public boolean equals(Object o) {
if(o instanceof StudentPK) {
StudentPK pk = (StudentPK)o;
if(this.id == pk.getId() && this.name.equals(pk.getName())) {
return true;
}
}
return false;
}

@Override
public int hashCode() {
return this.name.hashCode();
}
}

package com.bjsxt.hibernate;

public class Student {

private StudentPK pk;

private int age;
private String sex;
private boolean good;
public boolean isGood() {
return good;
}
public void setGood(boolean good) {
this.good = good;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public StudentPK getPk() {
return pk;
}
public void setPk(StudentPK pk) {
this.pk = pk;
}
}

Student.hbm.xml：

<hibernate-mapping>
<class name="com.bjsxt.hibernate.Student">

<composite-id name="pk" class="com.bjsxt.hibernate.StudentPK">
<key-property name="id"></key-property>
<key-property name="name"></key-property>
</composite-id>

<property name="age" />
<property name="sex" />
<property name="good" type="yes_no"></property>
</class>

</hibernate-mapping>

测试文件：

import java.util.Date;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.AnnotationConfiguration;
import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.Test;

public class HibernateIDTest {
private static SessionFactory sessionFactory;

@BeforeClass
public static void beforeClass() {
sessionFactory = new AnnotationConfiguration().configure().buildSessionFactory();
}
@AfterClass
public static void afterClass() {
sessionFactory.close();
}

@Test
public void testStudentSave() {
StudentPK pk = new StudentPK();
pk.setId(5);
pk.setName("zhangsan5");
Student s = new Student();
s.setPk(pk);
s.setAge(8);

Session session = sessionFactory.getCurrentSession();
session.beginTransaction();
session.save(s);
session.getTransaction().commit();
}

@Test
public void testTeacherSave() {

Teacher t = new Teacher();
t.setId(5);
t.setName("t5");
t.setTitle("middle5");
t.setBirthDate(new Date());

Session session = sessionFactory.getCurrentSession();
session.beginTransaction();
session.save(t);
session.getTransaction().commit();
}

public static void main(String[] args) {
beforeClass();
}
}