Hibernate中one-to-many的基本操作

数据库

drop database if exists stuInfo;

create database if not exists stuInfo;

use stuInfo;

drop table if exists login;

create table if not exists login
(
loginId int auto_increment primary key,
loginName varchar(20) not null,
passwd varchar(20)
);

insert into login(loginName,passwd) values('admin','1234');
insert into login(loginName,passwd) values('user','1234');

drop table if exists classes;

create table if not exists classes
(
classId int auto_increment primary key,
className varchar(20) not null
);

insert into classes(className) values('ETP1');
insert into classes(className) values('ETP2');
insert into classes(className) values('ETP3');
insert into classes(className) values('ETP4');
insert into classes(className) values('ETP5');

drop table if exists student;

create table if not exists student
(
stuId int auto_increment primary key,
stuName varchar(20) not null,
stuSex smallint default 0,
stuAge smallint default 20,
stuBirth date,
stuHobby varchar(30),
stuStatus smallint,
fclassId int,
foreign key(fclassId) references classes(classId)
);

insert into student(stuName,stuSex,stuAge,stuBirth,stuHobby,stuStatus,fclassId) values('stu1',1,20,'1989-09-09 08:08:22','music;sport',1,1);
insert into student(stuName,stuSex,stuAge,stuBirth,stuHobby,stuStatus,fclassId) values('stu2',0,21,'1989-01-01 08:08:23','music;sport',1,1);
insert into student(stuName,stuSex,stuAge,stuBirth,stuHobby,stuStatus,fclassId) values('stu3',1,22,'1989-02-02 08:08:24','music;sport',1,2);
insert into student(stuName,stuSex,stuAge,stuBirth,stuHobby,stuStatus,fclassId) values('stu4',0,23,'1989-03-03 08:08:25','music;sport',1,2);
insert into student(stuName,stuSex,stuAge,stuBirth,stuHobby,stuStatus,fclassId) values('stu5',1,24,'1989-04-04 08:08:26','music;sport',1,3);
insert into student(stuName,stuSex,stuAge,stuBirth,stuHobby,stuStatus,fclassId) values('stu6',1,25,'1989-05-05 08:08:27','music;sport',1,5);

select stuId,stuSex,stuName,stuAge,stuBirth,stuHobby,stuStatus,fclassId FROM student;
select classId,className from classes;
select loginName,passwd from login;

Pojo

package com.xy.pojo;

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

public class Classes implements java.io.Serializable
{

// Fields

private Integer classId;
private String className;
private Set students = new HashSet(0);

// Constructors

/** default constructor */
public Classes()
{
}

/** minimal constructor */
public Classes(String className)
{
this.className = className;
}

/** full constructor */
public Classes(String className, Set students)
{
this.className = className;
this.students = students;
}

// Property accessors

public Integer getClassId()
{
return this.classId;
}

public void setClassId(Integer classId)
{
this.classId = classId;
}

public String getClassName()
{
return this.className;
}

public void setClassName(String className)
{
this.className = className;
}

public Set getStudents()
{
return this.students;
}

public void setStudents(Set students)
{
this.students = students;
}

}

<?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.xy.pojo.Classes" table="classes" catalog="stuinfo">
<id name="classId" type="java.lang.Integer">
<column name="classId" />
<generator class="native" />
</id>
<property name="className" type="java.lang.String">
<column name="className" length="20" not-null="true" />
</property>
<set name="students" inverse="true" cascade="all">
<key>
<column name="fclassId" />
</key>
<one-to-many class="com.xy.pojo.Student" />
</set>
</class>
</hibernate-mapping>

package com.xy.pojo;

import java.util.Date;

public class Student implements java.io.Serializable
{

// Fields

private Integer stuId;
private Classes classes;
private String stuName;
private Short stuSex;
private Short stuAge;
private Date stuBirth;
private String stuHobby;
private Short stuStatus;

// Constructors

/** default constructor */
public Student()
{
}

/** minimal constructor */
public Student(String stuName)
{
this.stuName = stuName;
}

/** full constructor */
public Student(Classes classes, String stuName, Short stuSex, Short stuAge, Date stuBirth, String stuHobby, Short stuStatus)
{
this.classes = classes;
this.stuName = stuName;
this.stuSex = stuSex;
this.stuAge = stuAge;
this.stuBirth = stuBirth;
this.stuHobby = stuHobby;
this.stuStatus = stuStatus;
}

// Property accessors

public Integer getStuId()
{
return this.stuId;
}

public void setStuId(Integer stuId)
{
this.stuId = stuId;
}

public Classes getClasses()
{
return this.classes;
}

public void setClasses(Classes classes)
{
this.classes = classes;
}

public String getStuName()
{
return this.stuName;
}

public void setStuName(String stuName)
{
this.stuName = stuName;
}

public Short getStuSex()
{
return this.stuSex;
}

public void setStuSex(Short stuSex)
{
this.stuSex = stuSex;
}

public Short getStuAge()
{
return this.stuAge;
}

public void setStuAge(Short stuAge)
{
this.stuAge = stuAge;
}

public Date getStuBirth()
{
return this.stuBirth;
}

public void setStuBirth(Date stuBirth)
{
this.stuBirth = stuBirth;
}

public String getStuHobby()
{
return this.stuHobby;
}

public void setStuHobby(String stuHobby)
{
this.stuHobby = stuHobby;
}

public Short getStuStatus()
{
return this.stuStatus;
}

public void setStuStatus(Short stuStatus)
{
this.stuStatus = stuStatus;
}

}

<?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.xy.pojo.Student" table="student" catalog="stuinfo">
<id name="stuId" type="java.lang.Integer">
<column name="stuId" />
<generator class="native" />
</id>
<many-to-one name="classes" class="com.xy.pojo.Classes"
fetch="select">
<column name="fclassId" />
</many-to-one>
<property name="stuName" type="java.lang.String">
<column name="stuName" length="20" not-null="true" />
</property>
<property name="stuSex" type="java.lang.Short">
<column name="stuSex" />
</property>
<property name="stuAge" type="java.lang.Short">
<column name="stuAge" />
</property>
<property name="stuBirth" type="java.util.Date">
<column name="stuBirth" length="10" />
</property>
<property name="stuHobby" type="java.lang.String">
<column name="stuHobby" length="30" />
</property>
<property name="stuStatus" type="java.lang.Short">
<column name="stuStatus" />
</property>
</class>
</hibernate-mapping>

HibernateSessionFactory

package com.xy.pojo;

import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.cfg.Configuration;

public class HibernateSessionFactory
{

private static String CONFIG_FILE_LOCATION = "/hibernate.cfg.xml";
private static final ThreadLocal<Session> threadLocal = new ThreadLocal<Session>();
private static Configuration configuration = new Configuration();
private static org.hibernate.SessionFactory sessionFactory;
private static String configFile = CONFIG_FILE_LOCATION;

static
{
try
{
configuration.configure(configFile);
sessionFactory = configuration.buildSessionFactory();
}
catch (Exception e)
{
System.err.println("%%%% Error Creating SessionFactory %%%%");
e.printStackTrace();
}
}

private HibernateSessionFactory()
{
}

/**
* Returns the ThreadLocal Session instance. Lazy initialize the
* <code>SessionFactory</code> if needed.
*
* @return Session
* @throws HibernateException
*/
public static Session getSession() throws HibernateException
{
Session session = (Session) threadLocal.get();

if (session == null || !session.isOpen())
{
if (sessionFactory == null)
{
rebuildSessionFactory();
}
session = (sessionFactory != null) ? sessionFactory.openSession() : null;
threadLocal.set(session);
}

return session;
}

/**
* Rebuild hibernate session factory
*
*/
public static void rebuildSessionFactory()
{
try
{
configuration.configure(configFile);
sessionFactory = configuration.buildSessionFactory();
}
catch (Exception e)
{
System.err.println("%%%% Error Creating SessionFactory %%%%");
e.printStackTrace();
}
}

/**
* Close the single hibernate session instance.
*
* @throws HibernateException
*/
public static void closeSession() throws HibernateException
{
Session session = (Session) threadLocal.get();
threadLocal.set(null);

if (session != null)
{
session.close();
}
}

/**
* return session factory
*
*/
public static org.hibernate.SessionFactory getSessionFactory()
{
return sessionFactory;
}

/**
* return session factory
*
* session factory will be rebuilded in the next call
*/
public static void setConfigFile(String configFile)
{
HibernateSessionFactory.configFile = configFile;
sessionFactory = null;
}

/**
* return hibernate configuration
*
*/
public static Configuration getConfiguration()
{
return configuration;
}

}

hibernate.cfg.xml

<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<!-- Generated by MyEclipse Hibernate Tools. -->
<hibernate-configuration>

<session-factory>
<property name="dialect">
org.hibernate.dialect.MySQLDialect
</property>
<property name="connection.url">
jdbc:mysql://localhost:3306/stuinfo
</property>
<property name="connection.username">root</property>
<property name="connection.password">root</property>
<property name="connection.driver_class">
com.mysql.jdbc.Driver
</property>
<property name="myeclipse.connection.profile">
xy_mysql
</property>
<mapping resource="com/xy/pojo/Student.hbm.xml" />
<mapping resource="com/xy/pojo/Classes.hbm.xml" />

</session-factory>

</hibernate-configuration>

package com.xy.test;

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

import com.xy.pojo.Classes;
import com.xy.pojo.HibernateSessionFactory;
import com.xy.pojo.Student;

public class Test
{
public void test01()
{
Session session = null;
Transaction tran = null;
try
{
session = HibernateSessionFactory.getSession();
tran = session.beginTransaction();

// 将学号为30的学生的班级设为3班
Classes c = (Classes) session.createQuery("from Classes c where c.classId=3").uniqueResult();
Student s = (Student) session.createQuery("from Student s where s.stuId=30").uniqueResult();
s.setClasses(c);
tran.commit();
}
catch (Exception e)
{
e.printStackTrace();
tran.rollback();
}
finally
{
HibernateSessionFactory.closeSession();
}
}

public void test02()
{
Session session = null;
Transaction tran = null;
try
{
session = HibernateSessionFactory.getSession();
tran = session.beginTransaction();

// 此处在Classes.hbm.xml的one-to-many中设置了cascade=all
// 表明对Classes的所有CRUD操作，将会级联到Student上
// 比如删除班级号为3的班级，那么学生表中班级为3的同学的记录也会被删除
Classes c = (Classes) session.createQuery("from Classes c where c.classId=3").uniqueResult();
session.delete(c);
tran.commit();
}
catch (Exception e)
{
e.printStackTrace();
tran.rollback();
}
finally
{
HibernateSessionFactory.closeSession();
}
}

public void test03()
{
Session session = null;
Transaction tran = null;
try
{
session = HibernateSessionFactory.getSession();
tran = session.beginTransaction();

// 根据班级号删除学生
Classes c = (Classes) session.createQuery("from Classes c where c.classId=2").uniqueResult();
int count = session.createQuery

("delete from Student s where s.classes=" + c.getClassId()).executeUpdate();
System.out.println(count);
tran.commit();
}
catch (Exception e)
{
e.printStackTrace();
tran.rollback();
}
finally
{
HibernateSessionFactory.closeSession();
}
}

public static void main(String[] args)
{
Test t = new Test();
t.test03();
}

}