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();
 }
}