Spring之WEB模块

Spring的WEB模块用于整合Web框架，例如Struts 1、Struts 2、JSF等

整合Struts 1

继承方式

Spring框架提供了ActionSupport类支持Struts 1的Action。继承了ActionSupport后就能获取Spring的BeanFactory，从而获得各种Spring容器内的各种资源

import  org.springframework.web.struts.ActionSupport;

public class CatAction extends ActionSupport{
      public ICatService getCarService(){
             return (ICatService) getWebApplicationContext().getBean("catService");
      }
      public ActionForward execute(ActionMappingmapping,ActionForm form,HttpServletRequest request,HttpServletResponseresponse){
             CatForm catForm = (CatForm) form;
             if("list".equals(catForm.getAction())){
                    returnthis.list(mapping,form,request,response);
             }
      }

      public ActionForward list(ActionMappingmapping,ActionForm form,HttpServletRequest request,HttpServletResponseresponse){
             CatForm catForm = (CatForm) form;
             ICatService catService =getCatService();
             List<Cat> catList =catService.listCats();
             request.setAttribute("carList",catList);

             return mapping.find("list");
      }
}

Spring在web.xml中的配置

<context-param><!--  Spring配置文件的位置-->
      <param-name>contextConfigLocation</param-name>
      <param-value>/WEB-INF/classes/applicationContext.xml</param-value>
</context-param>

<listener><!--  使用Listener加载Spring配置文件-->
      <listener-class>
             org.springframework.web.context.ContextLoaderListener
      </listener-class>
</listener>

<filter><!--  使用Spring自带的字符过滤器-->
      <filter-name>CharacterEncodingFilter</filter-name>
      <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
      <init-param>
             <param-name>encoding</param-name>
             <param-value>UTF-8</param-value>
      </init-param>
      <init-param>
             <param-name>forceEncoding</param-name>
             <param-value>true</param-value>
      </init-param>
</filter>
<filter-mapping>
      <filter-name>CharacterEncodingFilter</filter-name>
      <url-pattern>/*</url-pattern>
</filter-mapping>

如果与Hibernate结合使用，需要在web.xml中添加OpenSessionInViewFilter过滤器，将session范围扩大到JSP层，防止抛出延迟加载异常

<filter>
      <filter-name>hibernateFilter</filter-name>
      <filter-class>org.springframework.orm.hibernate3.support. OpenSessionInViewFilter</filter-class>
</filter>
<filter-mapping>
      <filter-name> hibernateFilter</filter-name>
      <url-pattern>*.do</url-pattern><!--  对Struts 1的Action启用-->
</filter-mapping>

代理方式

继承方式融入Spring非常简单，但是缺点是代码与Spring发生了耦合，并且Action并没有交给Spring管理，因此不能使用Spring的AOP、IoC特性，使用代理方式则可以避免这些缺陷

public class CatAction extends Action{  //此处继承的Struts 1的Action
      private ICatService catService；
      //setter、getter略

      public ActionForward execute(ActionMappingmapping,ActionForm form,HttpServletRequest request,HttpServletResponseresponse){
             CatForm catForm = (CatForm) form;
             if("list".equals(catForm.getAction())){
                    returnthis.list(mapping,form,request,response);
             }
      }

      public ActionForward list(ActionMappingmapping,ActionForm form,HttpServletRequest request,HttpServletResponseresponse){
             CatForm catForm = (CatForm) form;
             ICatService catService =getCatService();
             List<Cat> catList =catService.listCats();
             request.setAttribute("carList",catList);

             return mapping.find("list");
      }
}

这个Action没有与Spring发生耦合，只是定义了一个ICatService属性，然后由Spring负责注入

struts-congfig.xml配置

<form-beans>
      <form-bean name="catForm" type="com.clf.spring.CatForm">
</form-beans>

<action-mappings>
      <action name=" catForm"  path="/cat" type="com.clf.spring.CatAction">
             <forward name="list" path="/jsp/listCat.jsp"></forward>
      </action>
</action-mappings>

<!--  最核心的配置，该配置把Struts的Action交给Spring代理-->
<controller processorClass="org.springframework.web.struts.DelegatingRequestProcessor" />

<!-- controller配置生效后，Action的type属性就是去作用了，Struts不会用type属性指定的类来创建CatAction，而是到Spring配置中寻找，因此Spring中必须配置CatAction -->
<!--  Spring中配置Action使用的是name属性而不是id，Spring会截获"/cat.do"的请求，将catService通过setter方法注入到CatAction中，并调用execute()方法-->
<bean name="/cat" class=" com.clf.spring.CatAction">
      <property name="catService" ref="catService" />
</bean>

web.xml的配置与上面的继承方式相同

使用代理方式的Action可以配置拦截器等Spring特性，例如给CatAction配置方法前拦截器和返回后拦截器

<bean id="catBeforeInterceptor" class="org.springframework.aop.support.NameMatchMethodPointcutAdvodor">
      <property name="advice">
             <bean class="com.clf.spring.MethodBeforeInterceptor" />
      </property>
      <property name="mappedName" value="*"></property>
</bean>

<bean id="catAfterInterceptor" class="org.springframework.aop.support.NameMatchMethodPointcutAdvodor">
      <property name="advice">
             <bean class="com.clf.spring.MethodAfterInterceptor" />
      </property>
      <property name="mappedName" value="*"></property>
</bean>

<bean name="/cat" class="org.springframework.aop.framework.ProxyFactoryBean">
      <property name="interceptorNames">
             <list>
                    <value> catBeforeInterceptor</value>
                    <value> catAfterInterceptor</value>
             </list>
      </property>
      <property name="target">
             <bean class="com.clf.spring.CatAction">
                    <property name="catService" ref="catService"></property>
             </bean>
      </property>
</bean>

整合Struts 2

Spring整合Struts 2需要struts2-spring-2.011.jar包

public class CatAction{
      private ICatService catService;
      private Cat cat;
      //setter、getter略

      public String list(){
             catService.listCats();
             return ＂list＂;
      }

      public String add(){
             catService.createCat(cat);
             return list();
      }
}

struts.xml配置

除了正常的配置之外，还需要<contstant/>添加名为struts.objectFactory的常量，把值设为spring，表示该Action由Spring产生。然后把<action/>的class属性改为catAction，Struts 2将会到Spring中寻找名为catAction的bean

<constant name=" struts.objectFactory" value="spring" />

<packagename="cat" extends="struts-default">
<action name="*_cat" method="{1}" class="catAction">
      <param name="action" >{1}</param>
      <result>/list.jsp</result>
      <result name="list">/list.jsp</result>
</action>
</package>

Spring配置

<bean id="catAction" scope="prototype" class="com.clf.spring.CatAction">
      <property name="catService" ref="catService"></property>
</bean>

web.xml配置

<context-param><!--  Spring配置文件的位置-->
      <param-name>contextConfigLocation</param-name>
      <param-value>/WEB-INF/classes/applicationContext.xml</param-value>
</context-param>

<listener><!--  使用Listener加载Spring配置文件-->
      <listener-class>
             org.springframework.web.context.ContextLoaderListener
      </listener-class>
</listener>

<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>