hibernate3的一个简单实例

package com.ru.utils;会话工厂的工具类<wbr></wbr>

import org.hibernate.SessionFactory;

import org.hibernate.cfg.Configuration;

public class GetSession {

private static SessionFactory sf=null;

//实例块只会被调用一次

static{

//读取hibernate的配置文件并且初始化"hibernate.cfg.xml"如果放在src下可以不写

Configuration configuration=new Configuration().configure("hibernate.cfg.xml");

//创建会话工厂

sf=configuration.buildSessionFactory();

}

public static SessionFactory getSessionFactory(){

return sf;

}

}

开发流程

1.<wbr><wbr><wbr><wbr><wbr><wbr></wbr></wbr></wbr></wbr></wbr></wbr>创建一个项目

2.<wbr><wbr><wbr><wbr><wbr><wbr></wbr></wbr></wbr></wbr></wbr></wbr>画出一个简单项目框架示意图

3.<wbr><wbr><wbr><wbr><wbr><wbr></wbr></wbr></wbr></wbr></wbr></wbr>引入hibernate开发包(从网上下载google<wbr>hibernate<wbr><a href="http://www.hibernate.org/" style="text-decoration:none; color:rgb(76,107,115)">http://www.hibernate.org</a>),</wbr></wbr>完后我们

4.<wbr><wbr><wbr><wbr><wbr><wbr></wbr></wbr></wbr></wbr></wbr></wbr>开发hibernate有三种方法(开发顺序)该成mysql数据库

我们使用第二种开发项目

创建employe表.

create table employee(

id int primary key,

name varchar(64) not null,

email varchar(64) not null,

hiredate date not null);

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创建一个序列,将来用于主键的自增长:

--创建一个序列

create sequence emp_seq

start with 1

increment by 1

minvalue 1

nomaxvalue

nocycle

nocache

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5.<wbr><wbr><wbr><wbr><wbr><wbr></wbr></wbr></wbr></wbr></wbr></wbr>开发domain对象和对象关系映射文件

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对象关系映射文件:作用是用于指定domain对象和表的映射关系. ,该文件的取名有规范:

domain对象.hbm.xml,一般我们放在和domain对象同一个文件夹下(包下)

<wbr></wbr>

我们的Employee.hbml.xml配置文件:

<!DOCTYPE hibernate-mapping PUBLIC

<wbr><wbr><wbr><wbr><wbr><wbr>"-//Hibernate/Hibernate Mapping DTD 3.0//EN"</wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr>"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"&gt;</wbr></wbr></wbr></wbr></wbr></wbr>

<wbr></wbr>

<hibernate-mapping package="com.hsp.domain">

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;class name="Employee" table="employee"&gt;</wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;!-- id</wbr></wbr></wbr></wbr></wbr></wbr>元素用于指定主键属性-->

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;id name="id" column="id" type="java.lang.Integer"&gt;</wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;!--</wbr></wbr></wbr></wbr></wbr></wbr>该元素用于指定主键值生成策略hilo native increment sequence uuid -->

<wbr>&lt;!--如果是mysql的话:&lt;generator class="increment"&gt;&lt;/generator&gt;自增长改成这样</wbr><wbr>就可以了--&gt;</wbr><wbr><wbr><wbr><wbr><br><wbr><wbr><wbr><wbr>&lt;generator class="sequence"&gt;</wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;param name="sequence"&gt;emp_seq&lt;/param&gt;</wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;/generator&gt;</wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;/id&gt;</wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;!--</wbr></wbr></wbr></wbr></wbr></wbr>对其它属性还有配置-->

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;property name="name" type="java.lang.String"&gt;</wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;column name="name" not-null="false"<wbr>/&gt;</wbr></wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;/property&gt;</wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;property name="email" type="java.lang.String" &gt;</wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;column name="email" not-null="false"/&gt;</wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;/property&gt;</wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;property name="hiredate" type="java.util.Date"&gt;</wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;column name="hiredate" not-null="false" /&gt;</wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;/property&gt;</wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;/class&gt;</wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr></wbr></wbr></wbr></wbr></wbr></wbr>

</hibernate-mapping>

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6.<wbr><wbr><wbr><wbr><wbr><wbr></wbr></wbr></wbr></wbr></wbr></wbr>手动配置我们的hibernate.cfg.xml文件,该文件用于配置连接的数据库的类型,driver,

,用户名,密码,url ....同时管理对象关系映射文件,该文件的名称,我们一般不修改.

<wbr></wbr>

hibernate.cfg.xml配置文件

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

<!DOCTYPE hibernate-configuration PUBLIC

<wbr><wbr><wbr><wbr><wbr><wbr><wbr>"-//Hibernate/Hibernate Configuration DTD 3.0//EN"</wbr></wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr><wbr>"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd"&gt;</wbr></wbr></wbr></wbr></wbr></wbr></wbr>

<hibernate-configuration>

<session-factory>

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;!-- hibernate</wbr></wbr></wbr></wbr></wbr></wbr>设计者,给我们提供了一写常用的配置-->

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;!--</wbr></wbr></wbr></wbr></wbr></wbr>配置使用的driver -->

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;property name="connection.driver_class"&gt;oracle.jdbc.driver.OracleDriver&lt;/property&gt;</wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;property name="connection.username"&gt;scott&lt;/property&gt;</wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;property name="connection.password"&gt;tiger&lt;/property&gt;</wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;property name="connection.url"&gt;jdbc:oracle:thin:@127.0.0.1:1521:orclhsp&lt;/property&gt;</wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;!--</wbr></wbr></wbr></wbr></wbr></wbr>配置dialect方言,明确告诉hibernate连接是哪种数据库-->

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;property name="dialect"&gt;org.hibernate.dialect.OracleDialect&lt;/property&gt;</wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;!--</wbr></wbr></wbr></wbr></wbr></wbr>显示出对于sql -->

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;property name="show_sql"&gt;true&lt;/property&gt;<br></wbr></wbr></wbr></wbr></wbr></wbr>

<wbr>&lt;!-- 让hibernate给我们自动创建表 create <wbr>每次都创建新表,update,如果没表创建新表,如果有表,查看关系映射文件是否有变化,没有变化更新数据,有变化创建新表. --&gt;</wbr></wbr>

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

<!-- 当获取session的方式为getcurrentsession的时候需要配置 -->

<property name="hibernate.current_session_context_class">

thread

</property>

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;!--</wbr></wbr></wbr></wbr></wbr></wbr>指定管理的对象映射文件-->

<wbr><wbr><wbr><wbr><wbr><wbr>&lt;mapping resource="com/hsp/domain/Employee.hbm.xml"/&gt;</wbr></wbr></wbr></wbr></wbr></wbr>

</session-factory>

</hibernate-configuration>

<wbr>7.测试文件</wbr>

test.java

package com.ru.service;

import java.util.Date;

import java.util.Iterator;

import java.util.List;

import javax.transaction.HeuristicMixedException;

import javax.transaction.HeuristicRollbackExcepti<wbr>on;</wbr>

import javax.transaction.RollbackException;

import javax.transaction.SystemException;

import org.hibernate.HibernateException;

import org.hibernate.Query;

import org.hibernate.SessionFactory;

import org.hibernate.Transaction;

import org.hibernate.cfg.Configuration;

import org.hibernate.classic.Session;

import com.ru.domain.Employee;

import com.ru.utils.GetSession;

public class test1 {

public static void main(String[] args) {

insertuser();

//updateuser();

//deleteuser();

queryuser();

//loaduser();

// getuser();

}

//查询用户1

//getCurrentSession需要事务。并且session自动关闭。

public static void queryuser(){

SessionFactory sf=GetSession.getSessionFactory();

Session session=sf.getCurrentSession();

Transaction ts=session.beginTransaction();

//query查询,Employee是类,不是表。name是变量

try {

Query query=(Query)session.createQuery("from Employee where name='南成如'");

List<Employee> list=query.list();

for (Employee employee : list) {

System.out.print(employee.getId()+"--"+employee.getName()+"--"+employee.getEmail());

}

ts.commit();

} catch (HibernateException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

//查询用户2

//如果使用openSession不需要事务,需要手动关闭session

public static void loaduser(){

SessionFactory sf=GetSession.getSessionFactory();

Session session=sf.getCurrentSession();

Transaction ts=session.beginTransaction();

try {

Employee em=(Employee) session.load(Employee.class, 1);

System.out.print(em.getName());

ts.commit();

} catch (HibernateException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

//查询用户3

//如果使用openSession不需要事务,需要手动关闭session

public static void getuser(){

SessionFactory sf=GetSession.getSessionFactory();

Session session=sf.openSession();

try {

Employee em=(Employee) session.load(Employee.class, 4);

System.out.print(em.getName());

} catch (HibernateException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}finally{

if (session!=null) {

session.close();

}

}

}

//修改用户

public static void updateuser(){

//得到会话工厂

SessionFactory sf=GetSession.getSessionFactory();

//创建会话,得到连接

Session session=sf.openSession();

//设置事务

Transaction transation=session.beginTransaction();

//修改用户要先获取用户

//load会通过主键属性,获取给对象实例。

Employee em=(Employee)session.load(Employee.class, 1);//产生一个select语句

em.setName("如");//导致一个update语句

em.setEmail("*********@qq.com");

//提交事务,关闭会话

transation.commit();

session.close();

}

//删除用户

public static void deleteuser(){

//获取会话工厂

SessionFactory sf=GetSession.getSessionFactory();

//打开会话

Session session=sf.openSession();

//设置事务,增删改都要设置事务,否则不执行

Transaction ts=null;

try {

ts=session.beginTransaction();

//删除用户先要获取用户

Employee em=(Employee)session.load(Employee.class, 1);

session.delete(em);

//提交事务,关闭会话

ts.commit();

} catch (HibernateException e) {

// TODO Auto-generated catch block

if (ts!=null) {

ts.rollback();//回滚

}

throw new RuntimeException(e.getMessage());

}finally{

if (session!=null&&session.isOpen()) {

session.close();

}

}

}

//添加用户

public static void insertuser() {

//1.读取heibernate的配置文件hibernate.cfg.xml,并完成初始化

Configuration configure=new Configuration().configure("hibernate.cfg.xml");

//2.创建会话工厂

SessionFactory sf=configure.buildSessionFactory();

//3.创建session,相当于连接jdbc

Session session=sf.openSession();

//4.4.对hiberate而言,要求程序员,在进行 增加,删除,修改的时候使用事务提交,

Transaction transation=session.beginTransaction();

//5.创建对象

Employee e=new Employee();

e.setName("如");

e.setEmail("*********@qq.com");

e.setHiredate(new Date());

//6.save employee就是持久化该对象 (把对象保存到了数据库中称为一条记录)

//==>insert into ....[被hiberante封装]

session.save(e);

//提交事务。关闭会话

transation.commit();

session.close();

}

}

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