//适用于表里没有其他列，只有主键

//Course.java实体类

package com.tao.pojo;

import java.util.HashSet;

import java.util.Set;

public class Course {

    private int id;

    private String name;

    private Set<Student> stu=new HashSet<Student>();

    public Course() {

        super();

    }

    public Course(int id, String name) {

        super();

        this.id = id;

        this.name = 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;

    }

    public Set<Student> getStu() {

        return stu;

    }

    public void setStu(Set<Student> stu) {

        this.stu = stu;

    }

    @Override

    public String toString() {

        return "Course [id=" + id + ", name=" + name + "]";

    }

}

//Student.java实体类

package com.tao.pojo;

import java.util.HashSet;

import java.util.Set;

public class Student {

    private int id;

    private String name;

    private String gender;

    private Set<Course> cou=new HashSet<Course>();

    public Student() {

        super();

    }

    public Student(int id, String name, String gender) {

        super();

        this.id = id;

        this.name = name;

        this.gender = gender;

    }

    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 String getGender() {

        return gender;

    }

    public void setGender(String gender) {

        this.gender = gender;

    }

    public Set<Course> getCou() {

        return cou;

    }

    public void setCou(Set<Course> cou) {

        this.cou = cou;

    }

    @Override

    public String toString() {

        return "Student [id=" + id + ", name=" + name + ", gender=" + gender + "]";

    }

}

//配置文件

//course.hbm.xml文件名

<?xml version="1.0"?>

<!DOCTYPE hibernate-mapping PUBLIC

    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"

    "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">

<hibernate-mapping>

    <class name="com.tao.pojo.Course" table="course">

        <id name="id">

        <!-- 自动增长 -->

            <generator class="native"></generator>

        </id>

        <property name="name"/>

        <!-- name：实体来中的属性名 （Clazz的名称） clazz：属性类型（clazz的类型是Clazz）-->

        <!-- column：外键列名称 -->

        <!--stu是实体类中set集合的名，sc是表名 ， cid是Course在sc表中的外键， -->

        <set name="stu" table="sc">

            <key column="cid"></key>

            <!--set集合当中所存放的对象类型 Student类  sid是Student在sc表中的外键  -->

            <many-to-many class="com.tao.pojo.Student" column="sid"></many-to-many>

        </set>

    </class>

</hibernate-mapping>

//student.hbm.xml

<?xml version="1.0"?>

<!DOCTYPE hibernate-mapping PUBLIC

    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"

    "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">

<hibernate-mapping>

    <class name="com.tao.pojo.Student" table="student">

        <id name="id">

        <!-- 自动增长 -->

            <generator class="native"></generator>

        </id>

        <!--普通列  -->

        <property name="name"/>

        <property name="gender"/>

        <!-- set集合的配置   sid是Student在sc表中的列名-->

        <set name="cou" table="sc">

        <!-- Student 自己的键 -->

            <key column="sid"></key>

            <!--set的数据库类型    cid是Course在sc表中的外键 -->

            <!--Course的键  -->

            <many-to-many class="com.tao.pojo.Course" column="cid"></many-to-many>

        </set>

    </class>

</hibernate-mapping>

//映射文件hibernate.cfg.xml

<?xml version='1.0' encoding='utf-8'?>

<!DOCTYPE hibernate-configuration PUBLIC

        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"

        "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">

<hibernate-configuration>

    <session-factory>

    <!-- 自动生成表，数据库得手动创建 -->

        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>

        <property name="connection.url">jdbc:mysql://localhost:3306/test0105_MTM</property>

        <property name="connection.username">root</property>

        <property name="connection.password">root</property>

        <property name="show_sql">true</property>

        <property name="format_sql">true</property>

        <!-- 自动创建或更新表（没有就创建，有就更新 ）-->

        <property name="hbm2ddl.auto">update</property>

        <!--数据库方言（ 如果外键没有生成就把数据库方言设置一下   ） -->

        <!-- org.hibernate.dialect.MySQL5InnoDBDialect   是 mysql数据库方言的类名  在java文件里巧 MySQL5 选MySQL5InnoDBDialect  -->

        <!-- 如果执行完了没报错，外键还是没有，就把表删了，再执行一次 -->

        <property name="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property>

        <!--配置映射文件  -->

        <mapping resource="com/tao/pojo/course.hbm.xml"/>

        <mapping resource="com/tao/pojo/student.hbm.xml"/>

    </session-factory>

</hibernate-configuration>

//测试类

//TestJUnit.java

package com.tao.test;

import org.hibernate.Session;

import org.hibernate.SessionFactory;

import org.hibernate.cfg.Configuration;

import org.junit.After;

import org.junit.Before;

import org.junit.Test;

import com.tao.pojo.Course;

import com.tao.pojo.Student;

public class TestJUnit {

    SessionFactory factory ;

    Session session ;

    @Before

    public void test001() {

        Configuration configure = new Configuration().configure();

        factory= configure.buildSessionFactory();

        session= factory.openSession();

        session.beginTransaction();

    }

    @After

    public void test002() {

        session.getTransaction().commit();

        session.close();

        factory.close();

    }

    @Test

    public void TestStudent() {

    }

}

测试的时候测试类里不用写内容,这里用TestStudent()测试