Struts2 Hibernate集成示例教程
时间：2020-02-23 14:36:06 来源:igfitidea点击:
Struts2和Hibernate都是各自领域中广泛使用的框架。
今天，我们将学习如何将Struts2 Web应用程序框架与Hibernate ORM框架集成在一起。
Struts2 Hibernate
与Spring Hibernate Integration不同，Struts2框架没有提供可使用的插件。
因此，我们将需要使用Servlet侦听器来管理Hibernate SessionFactory。
让我们看看如何通过一个简单的Web应用程序示例将Struts2与Hibernate集成。
我们最终的项目结构将如下图所示，我们将逐一研究每个组件。
首先在Eclipse中创建"动态Web项目"，然后将其转换为maven项目，以为我们的Web应用程序准备好基本框架。
Struts2 Hibernate示例数据库设置
在身份验证用户出现在欢迎页面之后，我们将创建一个登录应用程序，其中将显示他的所有信息。
下面的SQL脚本将创建所需的表并插入将用于身份验证的数据。
setup.sql
CREATE TABLE `User` (
`user_id` varchar(10) NOT NULL DEFAULT '',
`password` varchar(40) NOT NULL DEFAULT '',
`name` varchar(40) NOT NULL DEFAULT '',
`email` varchar(40) NOT NULL DEFAULT '',
PRIMARY KEY (`user_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
INSERT INTO `User` (`user_id`, `password`, `name`, `email`)
VALUES
('hyman', 'hyman123', 'hyman Kumar', '[email protected]');
Struts2，Hibernate和MySQL Maven依赖关系
我们需要在pom.xml文件中添加Struts2，Hibernate和MySQL maven依赖项，最终的pom.xml文件如下所示。
<project xmlns="https://maven.apache.org/POM/4.0.0" xmlns:xsi="https://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="https://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>Struts2Hibernate</groupId>
<artifactId>Struts2Hibernate</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>
<dependencies>
<dependency>
<groupId>org.apache.struts</groupId>
<artifactId>struts2-core</artifactId>
<version>2.3.15.1</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>4.3.5.Final</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.0.5</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<artifactId>maven-war-plugin</artifactId>
<version>2.3</version>
<configuration>
<warSourceDirectory>WebContent</warSourceDirectory>
<failOnMissingWebXml>false</failOnMissingWebXml>
</configuration>
</plugin>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
</plugins>
<finalName>${project.artifactId}</finalName>
</build>
</project>
我们在示例中使用的是Hibernate 4，但是相同的代码也可以在Hibernate 3中使用。
尽管您可能需要进行一些配置，但休眠3的特定更改。
Struts2 Hibernate示例部署描述符
我们需要通过在部署描述符中应用StrutsPrepareAndExecuteFilter在我们的Web应用程序中插入Struts2框架。
web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="https://www.w3.org/2001/XMLSchema-instance" xmlns="https://java.sun.com/xml/ns/javaee" xsi:schemaLocation="https://java.sun.com/xml/ns/javaee https://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0"> <display-name>Struts2Hibernate</display-name> <filter> <filter-name>struts2</filter-name> <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class> </filter> <filter-mapping> <filter-name>struts2</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <listener> <listener-class>com.theitroad.struts2hibernate.listener.HibernateServletContextListener</listener-class> </listener> </web-app>
注意，HibernateServletContextListener将用于管理Hibernate SessionFactory，稍后我们将看它的代码。
Entity Bean
我们的实体Bean还将用作struts2动作类模型Bean，如下所示。
User.java
package com.theitroad.struts2hibernate.model;
public class User {
private String id;
private String name;
private String pwd;
private String email;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPwd() {
return pwd;
}
public void setPwd(String pwd) {
this.pwd = pwd;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
@Override
public String toString(){
return "Name= "+name+", Email= "+email;
}
}
我正在使用基于XML的映射，但是我们也可以为我们的实体bean使用基于JPA注释的映射。
Hibernate DAO实现类
我们的UserDAO接口声明了将为User实体bean公开的方法。
UserDAO.java
package com.theitroad.struts2hibernate.dao;
import com.theitroad.struts2hibernate.model.User;
public interface UserDAO {
User getUserByCredentials(String userId, String password);
}
休眠特定的DAO实现如下所示。
UserDAOImpl.java
package com.theitroad.struts2hibernate.dao;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import com.theitroad.struts2hibernate.model.User;
public class UserDAOImpl implements UserDAO {
private SessionFactory sf;
public UserDAOImpl(SessionFactory sf){
this.sf = sf;
}
@Override
public User getUserByCredentials(String userId, String password) {
Session session = sf.openSession();
Transaction tx = session.beginTransaction();
Query query = session.createQuery("from User where id=:id and pwd=:pwd");
query.setString("id", userId); query.setString("pwd", password);
User user = (User) query.uniqueResult();
if(user != null){
System.out.println("User Retrieved from DB::"+user);
}
tx.commit();session.close();
return user;
}
}
Servlet上下文侦听器
我们将在ServletContextListener实现中初始化Hibernate SessionFactory，当应用程序停止时，我们将销毁SessionFactory。
HibernateServletContextListener.java
package com.theitroad.struts2hibernate.listener;
import java.net.URL;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
public class HibernateServletContextListener implements ServletContextListener {
@Override
public void contextDestroyed(ServletContextEvent sce) {
SessionFactory sf = (SessionFactory) sce.getServletContext().getAttribute("SessionFactory");
sf.close();
}
@Override
public void contextInitialized(ServletContextEvent sce) {
URL url = HibernateServletContextListener.class.getResource("/hibernate.cfg.xml");
Configuration config = new Configuration();
config.configure(url);
ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder()
.applySettings(config.getProperties()).build();
SessionFactory sf = config.buildSessionFactory(serviceRegistry);
sce.getServletContext().setAttribute("SessionFactory", sf);
}
}
Struts2动作类
我们已经准备好了休眠专用的设置，让我们继续Struts2动作类。
LoginAction.java
package com.theitroad.struts2hibernate.action;
import javax.servlet.ServletContext;
import org.apache.struts2.util.ServletContextAware;
import org.hibernate.SessionFactory;
import com.theitroad.struts2hibernate.dao.UserDAO;
import com.theitroad.struts2hibernate.dao.UserDAOImpl;
import com.theitroad.struts2hibernate.model.User;
import com.opensymphony.xwork2.Action;
import com.opensymphony.xwork2.ModelDriven;
public class LoginAction implements Action, ModelDriven<User>, ServletContextAware {
@Override
public String execute() throws Exception {
SessionFactory sf = (SessionFactory) ctx.getAttribute("SessionFactory");
UserDAO userDAO = new UserDAOImpl(sf);
User userDB = userDAO.getUserByCredentials(user.getId(), user.getPwd());
if(userDB == null) return ERROR;
else {
user.setEmail(userDB.getEmail());
user.setName(userDB.getName());
return SUCCESS;
}
}
@Override
public User getModel() {
return user;
}
private User user = new User();
private ServletContext ctx;
@Override
public void setServletContext(ServletContext sc) {
this.ctx = sc;
}
}
Struts2，Hibernate配置和Hibernate映射XML
我们在Struts2配置文件中具有以下URI配置。
struts.xml
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN" "https://struts.apache.org/dtds/struts-2.3.dtd"> <struts> <constant name="struts.devMode" value="true"></constant> <constant name="struts.convention.result.path" value="/"></constant> <package name="user" namespace="/User" extends="struts-default"> <action name="home"> <result>/login.jsp</result> </action> <action name="login" class="com.theitroad.struts2hibernate.action.LoginAction"> <result name="success">/welcome.jsp</result> <result name="error">/error.jsp</result> </action> </package> </struts>
休眠配置文件如下所示。
hibernate.cfg.xml
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "https://hibernate.org/dtd/hibernate-configuration-3.0.dtd"> <hibernate-configuration> <session-factory> <!-- Database connection properties - Driver, URL, user, password --> <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property> <property name="hibernate.connection.url">jdbc:mysql://localhost/TestDB</property> <property name="hibernate.connection.username">hyman</property> <property name="hibernate.connection.password">hyman123</property> <!-- Connection Pool Size --> <property name="hibernate.connection.pool_size">1</property> <!-- org.hibernate.HibernateException: No CurrentSessionContext configured! --> <property name="hibernate.current_session_context_class">thread</property> <!-- Disable the second-level cache --> <property name="hibernate.cache.provider_class">org.hibernate.cache.internal.NoCacheProvider</property> <!-- Outputs the SQL queries, should be disabled in Production --> <property name="hibernate.show_sql">true</property> <!-- Dialect is required to let Hibernate know the Database Type, MySQL, Oracle etc Hibernate 4 automatically figure out Dialect from Database Connection Metadata --> <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property> <!-- mapping file, we can use Bean annotations too --> <mapping resource="User.hbm.xml" </session-factory> </hibernate-configuration>
Hibernate Mapping XML文件如下所示。
User.hbm.xml
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"https://hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="com.theitroad.struts2hibernate.model.User" table="USER">
<id name="id" type="java.lang.String">
<column name="USER_ID"
<generator class="assigned"
</id>
<property name="name" type="java.lang.String">
<column name="NAME"
</property>
<property name="pwd" type="java.lang.String">
<column name="PASSWORD"
</property>
<property name="email" type="java.lang.String">
<column name="EMAIL"
</property>
</class>
</hibernate-mapping>
Struts2查看页面
从struts2配置文件中可以看到，我们有三个视图页面。
它们是简单的页面，如下所示。
login.jsp
<%@ page language="java" contentType="text/html; charset=US-ASCII" pageEncoding="US-ASCII"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "https://www.w3.org/TR/html4/loose.dtd"> <%-- Using Struts2 Tags in JSP --%> <%@ taglib uri="/struts-tags" prefix="s"%> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>Login Page</title> </head> <body> <h3>Welcome User, please login below</h3> <s:form action="login"> <s:textfield name="id" label="User ID"></s:textfield> <s:textfield name="pwd" label="Password" type="password"></s:textfield> <s:submit value="Login"></s:submit> </s:form> </body> </html>
welcome.jsp
<%@ page language="java" contentType="text/html; charset=US-ASCII" pageEncoding="US-ASCII"%> <%@ taglib uri="/struts-tags" prefix="s"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "https://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>Welcome Page</title> </head> <body> <h3>Welcome <s:property value="name"></s:property></h3> <h3>Your id is <s:property value="id"></s:property></h3> <h3>Your password is <s:property value="pwd"></s:property></h3> <h3>Your email id is <s:property value="email"></s:property></h3> </body> </html>
error.jsp
<%@ page language="java" contentType="text/html; charset=US-ASCII" pageEncoding="US-ASCII"%> <%@ taglib uri="/struts-tags" prefix="s"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "https://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>Error Page</title> </head> <body> <h4>User Name or Password is wrong</h4> <s:include value="login.jsp"></s:include> </body> </html>
