many-to-many双向关联映射

Teacher.java

 

package com.model;

import java.util.HashSet;
import java.util.Set;

public class Teacher {
    private int id;
    private String name;
    private Set<Student> students = new HashSet<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 Set<Student> getStudents() {
        return students;
    }
    public void setStudents(Set<Student> students) {
        this.students = students;
    }

}

 

Student.java

 

package com.model;

import java.util.HashSet;
import java.util.Set;

public class Student {
    private int id;
    private String name;
    private Set<Teacher> teachers = new HashSet<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 Set<Teacher> getTeachers() {
        return teachers;
    }
    public void setTeachers(Set<Teacher> teachers) {
        this.teachers = teachers;
    }
}

 

Teacher.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 package="com.model">
    <class name="Teacher" table="teacher">
        <id name="id" column="id">
            <generator class="native"></generator>
        </id>
        <property name="name" column="name"></property>
        <set name="students" table="s_t" inverse="true">
            <key column="teacherId"></key>
            <many-to-many column="studentId" class="Student"></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 package="com.model">
    <class name="Student" table="student">
        <id name="id" column="id">
            <generator class="native"></generator>
        </id>
        <property name="name" column="name"></property>
        <set name="teachers" table="s_t">
            <key column="studentId"></key>
            <many-to-many column="teacherId" class="Teacher"></many-to-many>
        </set>
    </class>

</hibernate-mapping>

 

单元测试:

 

@Test
public void t(){
    Session session = HibernateUtil.getInstance().getSession();
    session.beginTransaction();
      将夜www.jiangyea.com
    Student s = new Student();
    s.setName("ss");

    Teacher t = new Teacher();
    t.setName("t");

    s.getTeachers().add(t);
    //t.getStudents().add(s);

    session.save(s);
    session.save(t);

    session.getTransaction().commit();
    session.close();
}