struts与spring如何整合

一、struts与spring如何整合
线索从web.xml看起

<?xml version="1.0" encoding="UTF-8"?>
<web-app 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>app name</display-name>

    <welcome-file-list>
        <welcome-file>/index.jsp</welcome-file>
    </welcome-file-list>

    <listener>
        <listener-class>com.ramix.common.util.InitPlatformLoader</listener-class>
    </listener>

    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>
            /WEB-INF/spring/*.spring.xml
        </param-value>
    </context-param>

    <!-- Spring的过滤器 -->
    <filter>
        <filter-name>OpenSessionFilter</filter-name>
        <filter-class>org.springframework.orm.hibernate3.support.OpenSessionInViewFilter</filter-class>
        <init-param>
            <param-name>singleSession</param-name>
            <param-value>true</param-value>
        </init-param>
    </filter>
    <!-- 编码转换过滤器 -->
    <filter>
        <filter-name>encodingFilter</filter-name>
        <filter-class>com.ramix.common.webapp.filter.EncodingFilter</filter-class>
    </filter>
    <!--sitemesh过滤器-->
    <filter>
        <filter-name>sitemesh</filter-name>
        <filter-class>com.opensymphony.module.sitemesh.filter.PageFilter</filter-class>
        <init-param>
            <param-name>configFile</param-name>
            <param-value>/WEB-INF/classes/sitemesh.xml</param-value>
        </init-param>
    </filter>
    <!--session-->
    <filter-mapping>
        <filter-name>OpenSessionFilter</filter-name>
        <url-pattern>*.do</url-pattern>
    </filter-mapping>
    <!--encode-->
    <filter-mapping>
        <filter-name>encodingFilter</filter-name>
        <url-pattern>*.do</url-pattern>
    </filter-mapping>
    <!--sitemesh过滤-->
    <filter-mapping>
        <filter-name>sitemesh</filter-name>
        <url-pattern>*.do</url-pattern>
    </filter-mapping>

    <!-- struts 的配置 -->
    <servlet>
        <servlet-name>action</servlet-name>
        <servlet-class>org.apache.struts.action.ActionServlet</servlet-class>
        <init-param>
            <param-name>config</param-name>
            <param-value>
                /WEB-INF/struts/struts-config.xml,
                /WEB-INF/struts/action/fileupload-action-config.xml,
                /WEB-INF/struts/action/demo-action-config.xml
            </param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>action</servlet-name>
        <url-pattern>*.do</url-pattern>
    </servlet-mapping>
    <!--showpic-->
    <servlet>
        <servlet-name>showphoto</servlet-name>
        <servlet-class>com.ramix.demo.webapp.servlet.ShowParentPicServlet</servlet-class>
        <init-param>
            <param-name>noimage</param-name>
            <param-value>/images/noimage.gif</param-value>
        </init-param>
    </servlet>
    <servlet-mapping>
        <servlet-name>showphoto</servlet-name>
        <url-pattern>/showphoto</url-pattern>
    </servlet-mapping>
    <!--cxf-->
    <servlet>
        <servlet-name>cxf</servlet-name>
        <servlet-class>
            org.apache.cxf.transport.servlet.CXFServlet
        </servlet-class>
        <load-on-startup>2</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>cxf</servlet-name>
        <url-pattern>/ws/*</url-pattern>
    </servlet-mapping>

    <error-page>
        <error-code>404</error-code>
        <location>/WEB-INF/page/common/e404.jsp</location>
    </error-page>
    <error-page>
        <error-code>500</error-code>
        <location>/WEB-INF/page/common/e500.jsp</location>
    </error-page>
</web-app>

这里我们要关注的是两个地方的配置文件
1、/WEB-INF/spring/*.spring.xml
2、/WEB-INF/struts/struts-config.xml,/WEB-INF/struts/action/fileupload-action-config.xml,/WEB-INF/struts/action/demo-action-config.xml

{1}中放置的配置文件是关于service层的配置
如：demo.spring.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN 2.0//EN"
	"http://www.springframework.org/dtd/spring-beans-2.0.dtd">

<beans>
	<bean id="parentManager" parent="baseTxService">
		<property name="target">
			<bean class="com.ramix.demo.service.impl.ParentManagerImpl" autowire="byName">
				<property name="childMgr" ref="childManager"/>
			</bean>
		</property>
	</bean>

	<bean id="childManager" parent="baseTxService">
		<property name="target">
			<bean class="com.ramix.demo.service.impl.ChildManagerImpl" autowire="byName"/>
		</property>
	</bean>

	<bean id="jdbcManager" parent="baseTxService">
		<property name="target">
			<bean class="com.ramix.demo.service.impl.JdbcManagerImpl" autowire="byName" parent="jdbcDao"/>
		</property>
	</bean>

</beans>

{2}中放置的都是struts的配置文件
如：/WEB-INF/sturts/action/demo-action-config.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts-config PUBLIC
	"-//Apache Software Foundation//DTD Struts Configuration 1.2//EN"
	"http://struts.apache.org/dtds/struts-config_1_2.dtd">
<struts-config>
	<action-mappings>
		<action path="/demo/list"
				type="com.ramix.demo.webapp.action.DemoListAction"
				parameter="method"
				scope="request"
				name="globalForm">
			<forward name="view" path="/WEB-INF/page/demo/list.jsp"/>
		</action>
		<action path="/demo/create" forward="/WEB-INF/page/demo/create.jsp"/>
		<action path="/demo/save"
				type="com.ramix.demo.webapp.action.DemoSaveAction"
				parameter="method"
				scope="request"
				name="globalForm">
			<forward name="view" path="/demo/list.do"/>
		</action>
		<action path="/demo/client"
				type="com.ramix.demo.webapp.action.DemoClientAction"
				parameter="method"
				scope="request"
				name="globalForm">
			<forward name="view" path="/WEB-INF/page/demo/client.jsp"/>
		</action>
		<action path="/demo/mail" forward="/WEB-INF/page/demo/sendmail.jsp"/>
		<action path="/demo/send"
				type="com.ramix.demo.webapp.action.DemoSendAction"
				parameter="method"
				scope="request"
				name="globalForm"/>

		<action path="/demo/child/create"
				type="com.ramix.demo.webapp.action.DemoChildCreateAction"
				parameter="method"
				scope="request"
				name="globalForm">
			<forward name="view" path="/WEB-INF/page/demo/child_create.jsp"/>
		</action>
		<action path="/demo/child/save"
				type="com.ramix.demo.webapp.action.DemoChildSaveAction"
				parameter="method"
				scope="request"
				name="globalForm"/>
		<action path="/demo/child/list"
				type="com.ramix.demo.webapp.action.DemoChildListAction"
				parameter="method"
				scope="request"
				name="globalForm">
			<forward name="view" path="/WEB-INF/page/demo/child_list.jsp"/>
		</action>
		<action path="/demo/cahce_list" forward="/WEB-INF/page/demo/cache.jsp"/>
		<action path="/demo/child/list/ajax" forward="/WEB-INF/page/demo/child_list_ajax.jsp"/>
		<action path="/demo/ajax/child/list"
				type="com.ramix.demo.webapp.action.DemoAjaxChildListAction"
				parameter="method"
				scope="request"
				name="globalForm">
			<forward name="view" path="/WEB-INF/page/demo/ajax_list.jsp"/>
		</action>
		<action path="/demo/test"
				type="com.ramix.demo.webapp.action.DemoListAction"
				parameter="method"
				scope="request"
				name="globalForm">
			<forward name="test" path="/WEB-INF/page/demo/test.jsp"/>
		</action>
		
	</action-mappings>
</struts-config>

而衔接struts与spring的地方是在struts-config.xml中体现
/WEB-INF/struts/struts-config.xml:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts-config PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 1.2//EN"
    "http://struts.apache.org/dtds/struts-config_1_2.dtd">
<struts-config>
    <form-beans>
        <form-bean name="globalForm" type="org.apache.struts.action.DynaActionForm"/>
    </form-beans>

    <global-forwards>
        <forward name="globalError" path="/WEB-INF/page/common/error.jsp"/>
        <forward name="globalSuccess" path="/WEB-INF/page/common/success.jsp"/>
    </global-forwards>

	<!-- 
		利用了 <controller> 标记来用 DelegatingRequestProcessor 覆盖默认的 Struts RequestProcessor。
		下一步是在 Spring 配置文件中注册该动作
		
		DelegatingRequestProcessor自动地配置属性。这种设计使 Struts 动作并不知道它正被 Spring 管理，并且使您能够利用 Sping 的动作管理框架的所有优点。
	
		在请求转发给action之前，转发给Spring的Bean
	 -->
    <controller>
        <set-property property="processorClass"
                      value="org.springframework.web.struts.DelegatingRequestProcessor"/>
    </controller>

	<!-- 
	装载环境:需要使用 Spring 的 ContextLoaderPlugin 为 Struts 的 ActionServlet 装载 Spring 应用程序环境
	 -->
    <plug-in className="org.springframework.web.struts.ContextLoaderPlugIn">
        <set-property property="contextConfigLocation"
                      value="/WEB-INF/struts/spring/demo-action.spring.xml"/>
    </plug-in>
</struts-config>

要知道Struts转发的一个重要类是RequestProcessor，而现在通过对controller的设置将转发类被org.springframework.web.struts.DelegatingRequestProcessor替换，
而org.springframework.web.struts.DelegatingRequestProcessor只是封装了RequestProcessor，这样struts的转发就由spring来处理了。

问题：这里的plug-in标签的作用是什么？可以不写plugin-in这个标签吗？
1、其实plug-in只是为了装载Struts的ActionServlet用的，如果在web.xml的context-param中已经指定了这个Struts的ActionServlet配置文件，那么此时可以不写plug-in。
2、如果在web.xml的context-param中并没有指定这个Struts的ActionServlet配置文件，那么必须加上plug-in
3、plug-in中contextConfigLocation属性的作用是什么？可以不要这个属性吗？
如果用了plug-in，那么contextConfigLocation属性的作用是指定Struts的ActionServlet配置文件所在的位置；
如果去掉了contextConfigLocation属性，那么Struts的ActionServlet配置文件将被指定为/WEB-INF/{app}-servlet.xml文件，
({app}指的是web.xml中servlet-name的值，此处为"action"

<!-- struts 的配置 -->
	    <servlet>
	        <servlet-name>action</servlet-name>
	        <servlet-class>org.apache.struts.action.ActionServlet</servlet-class>
	        <init-param>
	            <param-name>config</param-name>
	            <param-value>
	                /WEB-INF/struts/struts-config.xml,
	                /WEB-INF/struts/action/fileupload-action-config.xml,
	                /WEB-INF/struts/action/demo-action-config.xml
	            </param-value>
	        </init-param>
	        <load-on-startup>1</load-on-startup>
	    </servlet>
	    <servlet-mapping>
	        <servlet-name>action</servlet-name>
	        <url-pattern>*.do</url-pattern>
	    </servlet-mapping>

)
所以，这是就必须在/WEB-INF/下存在action-servlet.xml文件。

现在默认的/WEB-INF/action-servlet.xml文件或由plug-in的contextConfigLocation属性指定的/WEB-INF/struts/spring/demo-action.spring.xml文件内容应该结合
web.xml的struts配置中指定的config文件内容可以这样写：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
    <bean name="/demo/list" parent="baseTxService">
        <property name="target">
            <bean class="com.ramix.demo.webapp.action.DemoListAction" autowire="byName">
                <property name="mgr" ref="parentManager"/>
            </bean>
        </property>
    </bean>
    <bean name="/demo/save" parent="baseTxService">
        <property name="target">
            <bean class="com.ramix.demo.webapp.action.DemoSaveAction" autowire="byName">
                <property name="mgr" ref="parentManager"/>
            </bean>
        </property>
    </bean>
    <bean name="/demo/client" class="com.ramix.demo.webapp.action.DemoClientAction">
        <property name="dws" ref="demoClient"/>
    </bean>
    <bean name="/demo/send" class="com.ramix.demo.webapp.action.DemoSendAction">
        <property name="mgr" ref="mailSendManager"/>
    </bean>

    <bean name="/demo/child/create" parent="baseTxService">
        <property name="target">
            <bean class="com.ramix.demo.webapp.action.DemoChildCreateAction" autowire="byName">
                <property name="mgr" ref="parentManager"/>
            </bean>
        </property>
    </bean>
    <bean name="/demo/child/save" parent="baseTxService">
        <property name="target">
            <bean class="com.ramix.demo.webapp.action.DemoChildSaveAction" autowire="byName">
                <property name="PMgr" ref="parentManager"/>
                <property name="CMgr" ref="childManager"/>
            </bean>
        </property>
    </bean>
    <bean name="/demo/child/list" parent="baseTxService">
        <property name="target">
            <bean class="com.ramix.demo.webapp.action.DemoChildListAction" autowire="byName">
                <property name="mgr" ref="childManager"/>
            </bean>
        </property>
    </bean>
	
	<bean name="/demo/ajax/child/list" parent="baseTxService">
        <property name="target">
            <bean class="com.ramix.demo.webapp.action.DemoAjaxChildListAction" autowire="byName">
                <property name="mgr" ref="jdbcManager"/>
            </bean>
        </property>
    </bean>
    <bean name="/demo/test" parent="baseTxService">
    	<property name="target">
    		<bean class="com.ramix.demo.webapp.action.Test" autowire="byName">
    		</bean>
    	</property>
    </bean>
</beans>

其实这样配置的目的也就是为了利用spring的依赖注入，能够使得Struts的servletAction自如的使用service层的bean。

这里需要关注的一点是：
请看/WEB-INF/struts/action/demo-action-config.xml中的

<action path="/demo/test"
		type="com.ramix.demo.webapp.action.DemoListAction"
		parameter="method"
		scope="request"
		name="globalForm">
	<forward name="test" path="/WEB-INF/page/demo/test.jsp"/>
</action>

和/WEB-INF/struts/spring/demo-action.spring.xml中的

<bean name="/demo/test" parent="baseTxService">
	<property name="target">
		<bean class="com.ramix.demo.webapp.action.Test" autowire="byName">
		</bean>
	</property>
</bean>

当url中执行..../demo/test.do时，将会是个什么样的过程？
首先会到/WEB-INF/struts/spring/demo-action.spring.xml中去找name为"/demo/test"的bean，
1、找到了，则执行target属性中指定的bean（此bean就是ServletAction类）：com.ramix.demo.webapp.action.Test的execute方法，并通过autowire="byName"对该类的set方法进行依赖注入。
2、没找到，才会去/WEB-INF/struts/action/demo-action-config.xml中去找/demo/test.do,
并执行type属性中指定的ServletAction：com.ramix.demo.webapp.action.DemoListAction的execute方法

提问：servletAction中必须要写execute方法吗？
如果真的写了execute方法，那么就失去了parameter="method"的意义，如果这样做的话，那势必每个功能（通过页面操作增删改查）都需要写一个action类，这样会导致action类数量的急剧膨胀。
其实，struts的DispatchAction的execute方法被执行时，他的机制是去获得method参数，如果该参数有值，那么会去执行这个元素对应的方法。比如url是这样的.../demo/test.do?method=test
就会去执行对应的servletAction类中的test方法；如果method参数没有值，则会去执行unspecified方法。
这样我们可以通过在servletAction中多写几个方法就能很好的解决这个action类急剧膨胀的问题，从管理上看还能更加的简介。
所以如果重写了execute方法，那么就失去了这些功能。

现在可以看看com.ramix.demo.webapp.action.Test类可以怎么写了：

package com.ramix.demo.webapp.action;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;

import com.ramix.common.webapp.action.BaseAction;

public class Test extends BaseAction {
	@Override
	public ActionForward unspecified(ActionMapping mapping, ActionForm form,
			HttpServletRequest request, HttpServletResponse response) {
		request.setAttribute("test", "test");
		return mapping.findForward("test");
	}

	public ActionForward test(ActionMapping mapping, ActionForm form,
			HttpServletRequest request, HttpServletResponse response) {
		request.setAttribute("test", request.getParameter("test"));
		return mapping.findForward("test");
	}
}

unspecified是不带method参数是执行的方法
test是method参数值为test是执行的方法

当然如果应用很简单的，你并不需要parameter="method"的话，你非要写上execute方法也没有关系，就像下面代码这样：

package com.ramix.demo.webapp.action;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;

import com.ramix.common.webapp.action.BaseAction;

public class Test extends BaseAction {

	public ActionForward execute(ActionMapping mapping, ActionForm form,
			HttpServletRequest request, HttpServletResponse response)
			throws Exception {
		System.out.println("ok");
		System.out.println("ok1");
		return null;
	}
}



说明：这里的BaseAction只是对org.springframework.web.struts.DispatchActionSupport做了封装，代码如下：

package com.ramix.common.webapp.action;

import com.ramix.common.util.RequestParamUtil;
import org.apache.log4j.Logger;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.springframework.context.ApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;
import org.springframework.web.struts.DispatchActionSupport;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import java.util.Map;

/**
 * 基础的Action，提供一些action中最基本的方法
 *
 * @author: Feng
 * @since: 2007-11-30
 */
public class BaseAction extends DispatchActionSupport {
    // 用来输出log。
    protected final Logger log = Logger.getLogger(this.getClass());

    // 默认分页个数
    protected static final int DEF_PAGE_SIZE = 10;

    // 默认错误页
    protected static final String DEF_VIEW_PAGE = "view";

    // 默认错误页
    protected static final String DEF_ERROR_PAGE = "globalError";

    // 默认成功页
    protected static final String DEF_SUCCESS_PAGE = "globalSuccess";

    // 令牌名称
    protected static final String TOKEN_KEY = "RIMAX_TOKEN";

    /**
     * 用来得到spring注入的bean。
     *
     * @param beanName 在spring配置文件中定义的bean的名字。
     * @return 从ApplicationContext中得到的bean对象。
     */
    protected Object getBean(String beanName) {
        ApplicationContext ctx = WebApplicationContextUtils.getRequiredWebApplicationContext(servlet.getServletContext());
        return ctx.getBean(beanName);
    }

    /**
     * 从request取得目标页码，没有设置，默认显示第一页
     *
     * @param request HttpServletRequest
     * @return 目标页码
     */
    protected int getPageNum(HttpServletRequest request) {
        return RequestParamUtil.getIntParam(request, "pageNum", 1);
    }

    /**
     * 从request取得目标页码，没有设置，默认显示第一页
     *
     * @param request HttpServletRequest
     * @return 目标页码
     */
    protected int getPageSize(HttpServletRequest request) {
        return RequestParamUtil.getIntParam(request, "pageSize", DEF_PAGE_SIZE);
    }

    /**
     * 转向错误页面
     *
     * @param mapping ActionMapping
     * @param request HttpServletRequest
     * @param message 显示信息
     * @param url     目标地址
     * @return ActionForward
     */
    protected ActionForward toGobalError(ActionMapping mapping, HttpServletRequest request, String message, String url) {
        request.setAttribute("url", url);
        request.setAttribute("message", message);
        return mapping.findForward(DEF_ERROR_PAGE);
    }

    /**
     * 转向全局成功页面
     *
     * @param mapping ActionMapping
     * @param request HttpServletRequest
     * @param message 显示信息
     * @param url     目标地址
     * @return ActionForward
     */
    protected ActionForward toGobalSuccess(ActionMapping mapping, HttpServletRequest request, String message, String url) {
        request.setAttribute("url", url);
        request.setAttribute("message", message);
        return mapping.findForward(DEF_SUCCESS_PAGE);
    }

    /**
     * 验证当前提交的令牌，并不重置令牌
     *
     * @param request HttpServletRequest
     * @return 令牌是否有效
     */
    protected boolean validCurToken(HttpServletRequest request) {
        HttpSession session = request.getSession();
        if (session == null) {
            return false;
        }
        Map map = (Map) session.getAttribute(TOKEN_KEY);
        if (map == null) {
            return true;
        }
        String strToken = request.getParameter(TOKEN_KEY);
        if (strToken == null) {
            return false;
        }
        return map.containsKey(strToken);
    }

    /**
     * 删除当前令牌
     *
     * @param request HttpServletRequest
     */
    protected void removeCurToken(HttpServletRequest request) {
        HttpSession session = request.getSession();
        if (session == null) {
            return;
        }
        Map map = (Map) session.getAttribute(TOKEN_KEY);
        if (map == null) {
            return;
        }
        String strToken = request.getParameter(TOKEN_KEY);
        if (strToken == null) {
            return;
        }
        map.remove(strToken);
    }
}