简单易懂的hibernate例子

 

数据库文件：myproject.sql

/*
MySQL Data Transfer
Source Host: localhost
Source Database: myproject
Target Host: localhost
Target Database: myproject
Date: 2009/8/26 17:23:12
*/

SET FOREIGN_KEY_CHECKS=0;
-- ----------------------------
-- Table structure for users
-- ----------------------------
DROP TABLE IF EXISTS `users`;
CREATE TABLE `users` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
`password` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
`email` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=39 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

-- ----------------------------
-- Records
-- ----------------------------
INSERT INTO `users` VALUES ('34', '测试4', '123456', '[email protected]');
INSERT INTO `users` VALUES ('35', '测试5', '123456', '[email protected]');
INSERT INTO `users` VALUES ('36', '测试6', '123456', '[email protected]');
INSERT INTO `users` VALUES ('37', '测试7', '123456', '[email protected]');
INSERT INTO `users` VALUES ('38', '测试8', '123456', '[email protected]');

实体类：User.java

package usermap;

public class User {
private int id;
private String name;
private String password;
private String email;

public String getEmail() {
return email;
}

public void setEmail(String email) {
this.email = email;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public String getPassword() {
return password;
}

public void setPassword(String password) {
this.password = password;
}

public int getId() {
return id;
}

public void setId(int id) {
this.id = id;
}

}

hibernate类：HibernateBase.java

package usermap;

import org.hibernate.*;
import org.hibernate.cfg.*;
import java.util.*;
import java.io.IOException;
import java.io.PrintWriter;

public abstract class HibernateBase {
protected SessionFactory sessionFactory;// 会话工厂，用于创建会话
protected Session session;// hibernate会话
protected Transaction transaction; // hiberante事务

public HibernateBase() throws HibernateException {
this.initHibernate();
}

// 帮助方法
protected void initHibernate() throws HibernateException {

// 装载配置，构造SessionFactory对象
sessionFactory = new Configuration().configure().buildSessionFactory();
}

/**
*开始一个hibernate事务
*/
protected void beginTransaction() throws HibernateException {

session = sessionFactory.openSession();
transaction = session.beginTransaction();
}

/**
*结束一个hibernate事务。
*/
protected void endTransaction(boolean commit) throws HibernateException {

if (commit) {
transaction.commit();
} else {
// 如果是只读的操作，不需要commit这个事务。
transaction.rollback();
}
session.close();}
}

bean类：UserBean.java

package usermap;

import org.hibernate.*;
import org.hibernate.cfg.*;
import java.util.*;

/**
* 和course相关的业务逻辑
*/
public class UserBean extends HibernateBase {
public UserBean() throws HibernateException {
super();
}

/**
* 增加一个Course
*/
public void addUser(User user) throws HibernateException {
beginTransaction();
session.save(user);
endTransaction(true);
}

/**
* 查询系统中所有的Course，返回的是包含有Course持久对象的Iterator。
*/
public Iterator getAllUsers() throws HibernateException {
String queryString = ”from User u order by u desc”;
beginTransaction();
Query query = session.createQuery(queryString);
Iterator it = query.iterate();
return it;
}

/**
* 删除给定ID的course
*/
public void deleteUser(String id) throws HibernateException {
beginTransaction();
User user = (User) session.load(User.class, id);
session.delete(user);
endTransaction(true);
}

/**
* 按course的名字进行模糊查找，返回的是包含有Course持久对象的Iterator。
*/
public Iterator getSomeUser(String name) throws HibernateException {
String queryString = ”select u from User as u where u.name like :name”;
beginTransaction();
Query query = session.createQuery(queryString);
query.setString(”name”, ”%” + name + ”%”);
Iterator it = query.iterate();
return it;
}
}
user的映射：User.hbm.xml

<?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=”usermap.User” table=”users”>
<id name=”id”>
<generator class=”native”/>
</id>
<property name=”name”/>
<property name=”password”/>
<property name=”email”/>
</class>
</hibernate-mapping>

hibernate全局配置：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”>

<hibernate-configuration>

<session-factory>

<!-- 显示实际操作数据库时的SQL -->

<property name=”show_sql”>false</property>

<!-- SQL 方言，这边设定的是MySQL -->

<property name=”dialect”>org.hibernate.dialect.MySQLDialect</property>

<!-- JDBC 驱动程序 -->

<property name=”connection.driver_class”>com.mysql.jdbc.Driver</property>

<!-- JDBC URL　注意这边我设定的所使用的编码 -->

<property name=”connection.url”>jdbc:mysql://localhost:3306/myproject</property>

<!-- 数据库使用者 -->

<property name=”connection.username”>root</property>

<!-- 数据库密码 -->

<property name=”connection.password”>123456</property>

<!-- 以下设置对象与数据库表格映像文件 -->
<mapping resource=”usermap/User.hbm.xml”/>

</session-factory>

</hibernate-configuration>

测试网页：index.jsp

<%@ page language=”java” contentType=”text/html; charset=UTF-8”
pageEncoding=”UTF-8”%>
<%@ page import=”usermap.User”%>
<%@ page import=”usermap.UserBean”%>
<%@ page import=”java.util.*”%>
<!DOCTYPE html PUBLIC ”-//W3C//DTD HTML 4.01 Transitional//EN” ”http://www.w3.org/TR/html4/loose.dtd”>
<html>
<head>
<meta http-equiv=”Content-Type” content=”text/html; charset=UTF-8”>
<title>Insert title here</title>
</head>
<body>

<%
UserBean ub=new UserBean();
Iterator ii=ub.getAllUsers();

int i=0;
while(ii.hasNext()&&i<3){
User u=(User)ii.next();
out.print(u.getId()+u.getName()+”<br>”);
i++;
}

%>
</body>
</html>