多对多关联映射

例如：学生与老师的关系

实体类：

package com.chris.entity;

import java.util.Set;

/**
 * 老师
 * @author Administrator
 *
 */
public class Teacher {

	private int id;
	private String name;
	private Set<Student> students;
	
	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;
	}
}

 

package com.chris.entity;

import java.util.Set;

/**
 * 学生
 * @author Administrator
 *
 */
public class Student {

	private int id;
	private String name;
	private Set<Teacher> teachers;
	
	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;
	}
}

 

映射文件：

Teacher.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC 
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="com.chris.entity">
	
	<class name="Teacher">
		<id name="id">
			<generator class="native"/>
		</id>
		<property name="name"/>
		<!-- table属性指定第三方表名称 -->
		<set name="students" table="teacher_student">
			<!-- key 节点定义Teacher类在第三方表中存储的字段名 -->
			<key column="teacher_id"/>
			<!-- column属性指定了在第三方表中通过student_id字段查找Student -->
			<many-to-many class="Student" column="student_id"/>
		</set>
	</class>
</hibernate-mapping>

 Student.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC 
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="com.chris.entity">
	
	<class name="Student">
		<id name="id">
			<generator class="native"/>
		</id>
		<property name="name"/>
		<!-- table属性指定第三方表名称 -->
		<set name="teachers" table="teacher_student">
			<key column="student_id"/>
			<many-to-many class="Teacher" column="teacher_id"/>
		</set>
	</class>
</hibernate-mapping>