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;

 }

}

<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>

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();

 }

}