hibernate3的一个简单实例
package com.ru.utils;会话工厂的工具类
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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)
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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"></wbr></wbr></wbr></wbr></wbr></wbr>
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<hibernate-mapping package="com.hsp.domain">
<wbr><wbr><wbr><wbr><wbr><wbr><class name="Employee" table="employee"></wbr></wbr></wbr></wbr></wbr></wbr>
<wbr><wbr><wbr><wbr><wbr><wbr><!-- id</wbr></wbr></wbr></wbr></wbr></wbr>元素用于指定主键属性-->
<wbr><wbr><wbr><wbr><wbr><wbr><id name="id" column="id" type="java.lang.Integer"></wbr></wbr></wbr></wbr></wbr></wbr>
<wbr><wbr><wbr><wbr><wbr><wbr><!--</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><!--如果是mysql的话：<generator class="increment"></generator>自增长改成这样</wbr><wbr>就可以了--></wbr>
<wbr><wbr><wbr><wbr><br><wbr><wbr><wbr><wbr><generator class="sequence"></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>
<wbr><wbr><wbr><wbr><wbr><wbr><param name="sequence">emp_seq</param></wbr></wbr></wbr></wbr></wbr></wbr>
<wbr><wbr><wbr><wbr><wbr><wbr></generator></wbr></wbr></wbr></wbr></wbr></wbr>
<wbr><wbr><wbr><wbr><wbr><wbr></id></wbr></wbr></wbr></wbr></wbr></wbr>
<wbr><wbr><wbr><wbr><wbr><wbr><!--</wbr></wbr></wbr></wbr></wbr></wbr>对其它属性还有配置-->
<wbr><wbr><wbr><wbr><wbr><wbr><property name="name" type="java.lang.String"></wbr></wbr></wbr></wbr></wbr></wbr>
<wbr><wbr><wbr><wbr><wbr><wbr><column name="name" not-null="false"<wbr>/></wbr></wbr></wbr></wbr></wbr></wbr></wbr>
<wbr><wbr><wbr><wbr><wbr><wbr></property></wbr></wbr></wbr></wbr></wbr></wbr>
<wbr><wbr><wbr><wbr><wbr><wbr><property name="email" type="java.lang.String" ></wbr></wbr></wbr></wbr></wbr></wbr>
<wbr><wbr><wbr><wbr><wbr><wbr><column name="email" not-null="false"/></wbr></wbr></wbr></wbr></wbr></wbr>
<wbr><wbr><wbr><wbr><wbr><wbr></property></wbr></wbr></wbr></wbr></wbr></wbr>
<wbr><wbr><wbr><wbr><wbr><wbr><property name="hiredate" type="java.util.Date"></wbr></wbr></wbr></wbr></wbr></wbr>
<wbr><wbr><wbr><wbr><wbr><wbr><column name="hiredate" not-null="false" /></wbr></wbr></wbr></wbr></wbr></wbr>
<wbr><wbr><wbr><wbr><wbr><wbr></property></wbr></wbr></wbr></wbr></wbr></wbr>
<wbr><wbr><wbr><wbr><wbr><wbr></class></wbr></wbr></wbr></wbr></wbr></wbr>
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</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.
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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"></wbr></wbr></wbr></wbr></wbr></wbr></wbr>
<hibernate-configuration>
<session-factory>
<wbr><wbr><wbr><wbr><wbr><wbr><!-- 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><!--</wbr></wbr></wbr></wbr></wbr></wbr>配置使用的driver -->
<wbr><wbr><wbr><wbr><wbr><wbr><property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property></wbr></wbr></wbr></wbr></wbr></wbr>
<wbr><wbr><wbr><wbr><wbr><wbr><property name="connection.username">scott</property></wbr></wbr></wbr></wbr></wbr></wbr>
<wbr><wbr><wbr><wbr><wbr><wbr><property name="connection.password">tiger</property></wbr></wbr></wbr></wbr></wbr></wbr>
<wbr><wbr><wbr><wbr><wbr><wbr><property name="connection.url">jdbc:oracle:thin:@127.0.0.1:1521:orclhsp</property></wbr></wbr></wbr></wbr></wbr></wbr>
<wbr><wbr><wbr><wbr><wbr><wbr><!--</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><property name="dialect">org.hibernate.dialect.OracleDialect</property></wbr></wbr></wbr></wbr></wbr></wbr>
<wbr><wbr><wbr><wbr><wbr><wbr><!--</wbr></wbr></wbr></wbr></wbr></wbr>显示出对于sql -->
<wbr><wbr><wbr><wbr><wbr><wbr><property name="show_sql">true</property><br></wbr></wbr></wbr></wbr></wbr></wbr>
<wbr><!-- 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. --></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><!--</wbr></wbr></wbr></wbr></wbr></wbr>指定管理的对象映射文件-->
<wbr><wbr><wbr><wbr><wbr><wbr><mapping resource="com/hsp/domain/Employee.hbm.xml"/></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();
}
}