举一个简单的例子：
Teacher.java
package zzn.hibernate.model;
import java.util.Set;
public class Teacher {
private int id;
private String name;
private int age;
private Set<Student> student;
public Set<Student> getStudent() {
return student;
}
public void setStudent(Set<Student> student) {
this.student = student;
}
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;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}
Student.java
package zzn.hibernate.model;
import java.util.Set;
public class Student {
private int id;
private String name;
private int age;
private Set<Teacher> teacher;
public Set<Teacher> getTeacher() {
return teacher;
}
public void setTeacher(Set<Teacher> teacher) {
this.teacher = teacher;
}
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;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}
Teacher.hbm.xml
<?xml version="1.0" encoding='gb2312'?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="zzn.hibernate.model">
<class name="Teacher" table="teacher" >
<id name="id" column="id">
<generator class="identity" />
</id>
<property name="name" />
<property name="age" />
<set name="Student" table="student_teacher">
<key column="teacher_id" />
<many-to-many class="Student" column="student_id" />
</set>
</class>
</hibernate-mapping>
Student.hbm.xml
<?xml version="1.0" encoding='gb2312'?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="zzn.hibernate.model">
<class name="Student" table="student" >
<id name="id" column="id">
<generator class="identity" />
</id>
<property name="name" />
<property name="age" />
<set name="Teacher" table="student_teacher">
<key column="student_id" />
<many-to-many class="Teacher" column="teacher_id" />
</set>
</class>
</hibernate-mapping>
hibernate-config.xml
<?xml version='1.0' encoding='gb2312'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<property name="show_sql">true</property>
<property name="hibernate.hbm2ddl.auto">update</property>
<property name="connection.username">sa</property>
<property name="connection.password"></property>
<property name="connection.url">jdbc:jtds:sqlserver://localhost:1433;databasename=hibernate_test</property>
<property name="dialect">org.hibernate.dialect.SQLServerDialect</property>
<property name="myeclipse.connection.profile">SQL2005</property>
<property name="connection.driver_class">net.sourceforge.jtds.jdbc.Driver</property>
<mapping resource="zzn/hibernate/mappings/Teacher.hbm.xml"/>
<mapping resource="zzn/hibernate/mappings/Student.hbm.xml"/>
</session-factory>
</hibernate-configuration>
ManyToManyTest.java
package zzn.hibernate.test;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import zzn.hibernate.base.HibernateUtil;
import zzn.hibernate.model.Student;
import zzn.hibernate.model.Teacher;
public class ManyToManyTest {
public static void main(String[] args) {
add();
get(1);
}
public static void add() {
Configuration configuration = null;
SessionFactory sessionFactory = null;
Session session = null;
Transaction transaction = null;
Student student = new Student();
Teacher teacher = new Teacher();
try {
configuration = new Configuration();
sessionFactory = configuration.configure().buildSessionFactory();
session = sessionFactory.openSession();
transaction = session.beginTransaction();
Set<Student> stu = new HashSet<Student>();
student.setName("zhaozhaonan");
student.setAge(25);
stu.add(student);
teacher.setName("zhangxiaolan");
teacher.setAge(25);
teacher.setStudent(stu);//建立关联
session.save(student);
session.save(teacher);
} finally {
if (session != null) {
transaction.commit();
session.close();
}
}
}
@SuppressWarnings("unchecked")
public static void get(int id) {
Session session = null;
Transaction transaction = null;
try {
session = HibernateUtil.getSession();
transaction = session.beginTransaction();
Student student = (Student)session.get(Student.class, id);
List list = new ArrayList (student.getTeacher());
for(int i=0;i<list.size();i++){
Teacher teacher = (Teacher)list.get(i);
System.out.println(teacher.getName());
}
} finally {
if (session != null) {
transaction.commit();
session.close();
}
}
}
}