Struts 2的拦截器（Interceptor）

package org.iridium.hellostruts;

import com.opensymphony.xwork2.ActionInvocation;

import com.opensymphony.xwork2.interceptor.AbstractInterceptor;

public class MyInterceptor extends AbstractInterceptor {

        @Override

        public String intercept(ActionInvocation invocation) throws Exception {

               /* let us do some pre-processing */

              String output = "Pre-Processing" ;

              System. out .println(output);

               /* let us call action or next interceptor */

              String result = invocation.invoke();

               /* let us do some post-processing */

              output = "Post-Processing" ;

              System. out .println(output);

               return result;

       }

}

<?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 = "helloworld" extends = "struts-default">

               <interceptors>

                      <interceptor name = "myinterceptor" class = "org.iridium.hellostruts.MyInterceptor" />

               </interceptors>

               <action name = "hello" class = "org.iridium.hellostruts.HelloWorldAction"

                      method = "execute">

                      <interceptor-ref name = "params" />

                      <!-- <interceptor-ref name="timer" /> -->

                      <interceptor-ref name = "myinterceptor" />

                      <result name = "success"> /HelloWorld.jsp </result >

                      <result name = "error"> /error.html </result >

               </action>

        </package>

</struts>

Pre-Processing

Inside Action!!!

Post-Processing

<package name="default" extends="struts-default">

   <interceptors>

        <interceptor name="timer" class=".."/>

        <interceptor name="logger" class=".."/>

        <interceptor-stack name="myStack">

           <interceptor-ref name="timer"/>

           <interceptor-ref name="logger"/>

        </interceptor-stack>

    </interceptors>

<action name="login"

     class="tutuorial.Login">

         <interceptor-ref name="myStack"/>

         <result name="input">login.jsp</result>

         <result name="success"

             type="redirectAction">/secure/home</result>

</action>

</package>