学步园

Teacher.java

package com.wansha.pojo;

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

public class Teacher{
	private int id;
	private String name;
	private Set<Student> set = 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> getSet() {
		return set;
	}
	public void setSet(Set<Student> set) {
		this.set = set;
	}
}

Student.java

package com.wansha.pojo;

public class Student{
	private int team_id;
	private String name;
	
	public int getTeam_id() {
		return team_id;
	}
	public void setTeam_id(int teamId) {
		team_id = teamId;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
}

Teacher.hbm.xml                  (不需要建立Student.hbm.xml文件)

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
 "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
  "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >
<hibernate-mapping>
	<class name="com.wansha.pojo.Teacher" table="teacher">
		<id name="id" column="id" type="int">
			<generator class="identity"></generator>
		</id>
		<property name="name" column="name" type="string" />
		<set name="set" table="student" cascade="all">
			<key column="teacher_id"/>
			<composite-element class="com.wansha.pojo.Student">
				<property name="name" column="name" type="string"></property>
			</composite-element>
		</set>
	</class>
</hibernate-mapping>

Test.java

package com.wansha.util;

import java.util.Iterator;
import java.util.Set;

import org.hibernate.Session;
import org.hibernate.Transaction;

import com.wansha.pojo.Student;
import com.wansha.pojo.Teacher;

public class Test {
	public static void main(String[] args) {
/*		Teacher teacher = new Teacher();
		teacher.setName("teacher zhang");
		
		Student student1 = new Student();
		student1.setName("sharp");
		
		Student student2 = new Student();
		student2.setName("hailie");
		
		teacher.getSet().add(student1);
		teacher.getSet().add(student2);
		
		Session session = HibernateUtil.getSession();
		Transaction ts = null;
		try{
			ts = session.beginTransaction();
			session.save(teacher);
			ts.commit();
		}catch(Exception ex){
			if(ts != null)ts.rollback();
			ex.printStackTrace();
		}finally{
			HibernateUtil.close(session);
		}
		*/
		
		
		Session session = HibernateUtil.getSession();
		Transaction ts = null;
		try{
			ts = session.beginTransaction();
			Teacher teacher = (Teacher)session.get(Teacher.class, 1);
			Set<Student> set = teacher.getSet();
			System.out.println(set.iterator().next().getName());
//			for(Iterator<Student> iter = set.iterator();iter.hasNext();){
//				System.out.println(iter.next().getName());
//			}
//			ts.commit();   //此句多出两句delete和insert语句
		}catch(Exception ex){
			if(ts != null)ts.rollback();
			ex.printStackTrace();
		}finally{
			HibernateUtil.close(session);
		}
	}

}