Struts2+Spring集成實例

在本教學中，我們來學習Struts2和Spring的集成。

1. 工程結構

下麵的圖是本教學的項目文件夾結構。

2. Spring監聽器

配置Spring監聽器 “org.springframework.web.context.ContextLoaderListener” 到 web.xml 文件中。

web.xml

<!DOCTYPE web-app PUBLIC
 "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
 "http://java.sun.com/dtd/web-app_2_3.dtd" >

<web-app>
  <display-name>Struts 2 Web Application</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>
      org.springframework.web.context.ContextLoaderListener
    </listener-class>
  </listener>
  
</web-app>

3. 注冊Spring Bean

注冊所有的Spring Beans 配置在 applicationContext.xml 文件中, Spring監聽器會自動找到這個 XML 文件。

applicationContext.xml

<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">
 
	<bean id="userBo" class="com.yiibai.user.bo.impl.UserBoImpl" />
	
	<bean id="userSpringAction" class="com.yiibai.user.action.UserSpringAction">
		<property name="userBo" ref="userBo" />	
	</bean>
 
</beans>

UserBo.java

package com.yiibai.user.bo;

public interface UserBo{

	public void printUser();
	
}

UserBoImpl.java

package com.yiibai.user.bo.impl;

import com.yiibai.user.bo.UserBo;

public class UserBoImpl implements UserBo{

	public void printUser(){
		System.out.println("printUser() is executed...");
	}
	
}

UserSpringAction.java

package com.yiibai.user.action;

import com.yiibai.user.bo.UserBo;

public class UserSpringAction{

	//DI via Spring
	UserBo userBo;
	
	public UserBo getUserBo() {
		return userBo;
	}

	public void setUserBo(UserBo userBo) {
		this.userBo = userBo;
	}

	public String execute() throws Exception {
		
		userBo.printUser();
		return "success";
		
	}
}

4. 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.devMode" value="true" />
 	
	<package name="default" namespace="/" extends="struts-default">
		
		<action name="userAction" 
			class="com.yiibai.user.action.UserAction" >
			<result name="success">pages/user.jsp</result>
		</action>
		
		<action name="userSpringAction" 
			class="userSpringAction" >
			<result name="success">pages/user.jsp</result>
		</action>
		
	</package>
	
</struts>

5. 示例

• 用例 1 : 讓 Spring 充當 Struts2的Action類，並訪問Spring的Bean。
• 用例 2 : 在Struts2的Action類中訪問Spring的Bean。

用例1

//struts.xml
<action name="userSpringAction" 
	class="userSpringAction" >
	<result name="success">pages/user.jsp</result>
</action>

//applicationContext.xml
<bean id="userSpringAction" class="com.yiibai.user.action.UserSpringAction">
	<property name="userBo" ref="userBo" />	
</bean> 

要訪問此操作，請使用網址： http://localhost:8080/struts2spring/userSpringAction.action

用例 2

默認情況下，Spring監聽器啟用 “通過匹配bean的名字自動裝配“。 因此，它會通過setUserBo自動傳遞Spring “userBo” Bean 到UserAction。請參閱下麵的Struts2動作：

UserAction.java

package com.yiibai.user.action;

import com.yiibai.user.bo.UserBo;
import com.opensymphony.xwork2.ActionSupport;
 
public class UserAction extends ActionSupport{

	//DI via Spring
	UserBo userBo;
	
	public UserBo getUserBo() {
		return userBo;
	}

	public void setUserBo(UserBo userBo) {
		this.userBo = userBo;
	}

	public String execute() throws Exception {
		
		userBo.printUser();
		return SUCCESS;
		
	}
}

要訪問此操作，請使用網址： http://localhost:8080/struts2spring/userAction.action

package com.yiibai.user.action;

import org.apache.struts2.ServletActionContext;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

import com.yiibai.user.bo.UserBo;
import com.opensymphony.xwork2.ActionSupport;
 
public class UserAction extends ActionSupport{

	public String execute() throws Exception {
		
		WebApplicationContext context =
			WebApplicationContextUtils.getRequiredWebApplicationContext(
                                    ServletActionContext.getServletContext()
                        );
		
		UserBo userBo1 = (UserBo)context.getBean("userBo");
		userBo1.printUser();

		return SUCCESS;
		
	}
}

參考

1. Struts2 Spring 插件文檔
2. Struts + Spring 集成實例