在这个项目中,准备用Struts2集成hibernate来完成数据库的简单CRUD操作,暂时不涉及集成spring。项目需要的lib文件：
antlr-2.7.6.jar
cglib-nodep-2.1_3.jar
commons-collections-3.1.jar
commons-logging-1.0.4.jar
dom4j-1.6.1.jar
ehcache-1.2.3.jar
freemarker-2.3.8.jar
hibernate3.jar
javassist-3.4.GA.jar
jta-1.1.jar
log4j-1.2.15.jar
mysql-connector-java-5.1.7-bin.jar
ognl-2.6.11.jar
servlet-api.jar
slf4j-api-1.5.6.jar
slf4j-log4j12-1.5.6.jar
struts2-core-2.0.14.jar
xwork-2.0.7.jar
在这个系统中将完成User对象的增、删、改、查功能。Uer对象的属性有id，name和password。
将分为如下几个步骤来完成：
1.编写Hibernate工具类
2.编写Hibernate拦截器控制事务
3.编写DAO类
4.编写User对象和hibernate映射文件
5.编写UserAction类
6.编写所需的listUser.jsp和editUser.jsp页面
7.编写struts配置文件
8.配置web.xml文件
9.发布测试
首先新建一个web project项目Struts2Hibernate，将上面所需的jar全部复制到WEB-INF下的lib文件夹中。
1.编写Hibernate工具类：
首先编写hibernate.cfg.xml文件，文件放在src目录下。此文件主要配置hibernate的数据库连接和事务管理。
<?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>
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/test</property>
<property name="hibernate.connection.username">root</property>
<property name="hibernate.connection.password"></property>
<property name="dialect">org.hibernate.dialect.MySQLDialect</property>
<property name="hibernate.current_session_context_class">thread</property>
<property name="hibernate.transaction.JDBCTransactionFactory">
org.hibernate.transaction.JDBCTransactionFactory
</property>
<!-- Echo all executed SQL to stdout -->
<property name="show_sql">true</property>
<!-- Drop and re-create the database schema on startup -->
<property name="hbm2ddl.auto">create</property>
<mapping resource="com/hibernate/domain/User.hbm.xml"/>
</session-factory>
</hibernate-configuration>
接着编写HibernateUtil类，用于获取SessionFactory实例。此类可以在hibernate-distribution-3.3.1.GA包的\project\tutorials下找到。
package com.hibernate.util;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class HibernateUtil 
{
private static final SessionFactory sessionFactory;
static {
try {
// Create the SessionFactory from hibernate.cfg.xml
sessionFactory = new Configuration().configure().buildSessionFactory();
} catch (Throwable ex) {
// Make sure you log the exception, as it might be swallowed
System.err.println("Initial SessionFactory creation failed." + ex);
throw new ExceptionInInitializerError(ex);
}
}
public static SessionFactory getSessionFactory() {
return sessionFactory;
}
}
接着编写一个ExportDB类，方便用户直接将写好的hibernate映射表结构创建到数据库中。此类可以单独直接运行。
package com.hibernate.util;
import org.hibernate.cfg.Configuration;
import org.hibernate.tool.hbm2ddl.SchemaExport;
public class ExportDB {
public static void main(String[] args) {
Configuration cf = new Configuration().configure();
SchemaExport se = new SchemaExport(cf);
se.create(false, true);
}
}
2.编写Hibernate拦截器控制事务
编写一个SessionInterceptor类来解决hibernate的lazyInitializationException。主要是采用过滤器的方式，在请求到达目标资源之前开始事务，在目标资源响应之后结束事务，来支持请求/响应模式所需的长事务。为了能执行此filter，需要在web.xml中增加filter。
package com.hibernate.web;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import org.hibernate.SessionFactory;
import org.hibernate.StaleObjectStateException;
import com.hibernate.util.HibernateUtil;
public class SessionInterceptor implements Filter {
private SessionFactory sf = null;
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
try{
if (sf.getCurrentSession()==null){
sf.openSession();
}else{
sf.getCurrentSession().beginTransaction();
}
chain.doFilter(request, response);
sf.getCurrentSession().getTransaction().commit();
}catch(StaleObjectStateException ex){
throw ex;
}catch(Throwable tx){
tx.printStackTrace();
try{
if(sf.getCurrentSession().getTransaction().isActive()){
sf.getCurrentSession().getTransaction().rollback();
}
}catch(Throwable rbEx){
System.err.println(rbEx.toString());
}
}
}
public void init(FilterConfig arg0) throws ServletException {
sf = HibernateUtil.getSessionFactory();
}
public void destroy() {
}
}
3.编写DAO类
编写一个DAOFactorty类用于屏蔽具体的DAO实现。
package com.hibernate.dao;
public abstract class DaoFactory {
private static final DaoFactory daoFactory = new HibernateDaoFactory();
public static DaoFactory getInstance(){
return daoFactory;
}
public abstract UserDao getUserDao();
}
编写HibernateDaoFactory工厂类，获得具体的DAO实现类。
package com.hibernate.dao;
import org.hibernate.Session;
import com.hibernate.dao.impl.UserDaoImpl;
import com.hibernate.util.HibernateUtil;
public class HibernateDaoFactory extends DaoFactory {
public UserDao getUserDao(){
UserDao userdao = new UserDaoImpl(getCurrentSession());
return userdao;
}
private Session getCurrentSession(){
return HibernateUtil.getSessionFactory().getCurrentSession();
}
}
编写UserDAO接口，便于不让上层依赖具体的DAO实现类。
package com.hibernate.dao;
import java.util.List;
import com.hibernate.domain.User;
public interface UserDao {
public User findById(Integer id);
public List<User> findAll();
public void makePersistent(User user);
public void delete(Integer id);
}
编写具体的实现类UserDaoImpl类
package com.hibernate.dao.impl;
import java.util.List;
import org.hibernate.Session;
import com.hibernate.dao.UserDao;
import com.hibernate.domain.User;
public class UserDaoImpl implements UserDao {
private Session session ;
public UserDaoImpl(Session session) {
this.session = session;
}
public Session getSession() {
return session;
}
public void delete(Integer id) {
session.delete(getSession().get(User.class, id));
}
public List<User> findAll() {
return session.createCriteria(User.class).list();
}
public User findById(Integer id) {
return (User)session.get(User.class, id);
}
public void makePersistent(User user) {
session.saveOrUpdate(user);
}
}
4.编写User对象和hibernate映射文件
编写领域对象User。
package com.hibernate.domain;
public class User {
private int id;
private String name;
private String password;
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 String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
对上述领域对象编写hibernate映射文件User.hbm.xml
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="com.hibernate.domain">
<class name="User" table="user">
<id name="id" column="id">
<generator class="native"/>
</id>
<property name="name"/>
<property name="password"/>
</class>
</hibernate-mapping>
5.编写UserAction类
在UserAction中完成User对象的CRUD相关函数的开发。同时需要创建3个属性，users,user,id
package com.struts2.action;
import java.util.List;
import com.hibernate.dao.DaoFactory;
import com.hibernate.domain.User;
import com.opensymphony.xwork2.ActionSupport;
import com.opensymphony.xwork2.Preparable;
public class UserAction extends ActionSupport implements Preparable {
private static final long serialVersionUID = -1057922687577124881L;
private List<User> users;
private User user;
private Integer id;
public List<User> getUsers() {
return users;
}
public void setUsers(List<User> users) {
this.users = users;
}
public User getUser() {
return user;
}
public void setUser(User user) {
this.user = user;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String list() throws Exception{
users = DaoFactory.getInstance().getUserDao().findAll();
return SUCCESS;
}
public String delete() throws Exception{
if(id!=null){
DaoFactory.getInstance().getUserDao().delete(id);
}
return SUCCESS;
}
public String save() throws Exception{
DaoFactory.getInstance().getUserDao().makePersistent(user);
return SUCCESS;
}
public void prepare() throws Exception{
if(id!=null){
user = DaoFactory.getInstance().getUserDao().findById(id);
}
}
}
6.编写所需的listUser.jsp和editUser.jsp页面
index.jsp如下：
<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="s" uri="/struts-tags"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>Struts2Hibernate</title>
</head>
<body>
Welcome to Struts2Hibernate Project
<p>
<a href="listUser.jsp">View all users</a>
</body>
</html>
listUser.jsp如下
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="s" uri="/struts-tags"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>Struts2Hibernate</title>
</head>
<body>
<table>
<tr>
<th>id</th>
<th>name</th>
<th>password</th>
</tr>
<s:iterator value="users">
<tr>
<td><a href="<s:url action="edit-%{id}"/>"><s:property value="id"/></a></td>
<td><s:property value="name" /></td>
<td><s:property value="password" /></td>
<td><a href="<s:url action="delete-%{id}"/>">delete</a></td>
</tr>
</s:iterator>
</table>
<p>
<a href="<s:url action="edit-" includeParams="none"/>">create new user</a>
</body>
</html>
editUser.jsp如下：
<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="s" uri="/struts-tags" %>
<!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=ISO-8859-1">
<title>Struts2Hibernate</title>
</head>
<body>
<s:if test="user!=null">
<s:text id="title" name="edit user"/>
</s:if>
<s:else>
<s:text id="title" name="create user"/>
</s:else>
<s:property value="#title"/>
<s:form action="save" method="post">
<s:hidden name="user.id" name="user.id" value="%{user.id}"></s:hidden>
<s:textfield label="name" name="user.name" value="%{user.name}"></s:textfield>
<s:password label="password" name="user.password" value="%{user.password}"></s:password>
<s:submit value="save"></s:submit>
</s:form>
</body>
</html>
7.编写struts配置文件struts.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
<constant name="struts.i18n.encoding" value="GBK" />
<package name="default" extends="struts-default">
<action name="list" class="com.struts2.action.UserAction" method="list">
<result name="success">/listUser.jsp</result>
<interceptor-ref name="basicStack" />
</action>
<action name="edit-*" class="com.struts2.action.UserAction">
<param name="id">{1}</param>
<result>/editUser.jsp</result>
<interceptor-ref name="static-params" />
<interceptor-ref name="basicStack" />
</action>
<action name="save" class="com.struts2.action.UserAction" method="save">
<result name="input">/editUser.jsp</result>
<result type="redirect">list.action</result>
</action>
<action name="delete-*" class="com.struts2.action.UserAction" method="delete">
<param name="id">{1}</param>
<result type="redirect">list.action</result>
<interceptor-ref name="static-params" />
</action>
</package>
</struts>
8.配置web.xml文件
注意：SessionInterceptor的filter要放在第一个filer的位置。
<?xml version="1.0" encoding="UTF-8"?>
<web-app id="WebApp_ID" version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<display-name>Struts2Hibernate</display-name>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
<filter>
<filter-name>SessionInterceptor</filter-name>
<filter-class>com.hibernate.web.SessionInterceptor</filter-class>
</filter>
<filter-mapping>
<filter-name>SessionInterceptor</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<filter>
<filter-name>struts2</filter-name>
<filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class>
</filter>
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
</web-app>
9.发布测试
posted on 2009-01-08 11:35
一叶笑天 阅读(1828)
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