1   /*
    2    * $Id: IncludeAction.java 54929 2004-10-16 16:38:42Z germuska $ 
    3    *
    4    * Copyright 2001-2004 The Apache Software Foundation.
    5    * 
    6    * Licensed under the Apache License, Version 2.0 (the "License");
    7    * you may not use this file except in compliance with the License.
    8    * You may obtain a copy of the License at
    9    * 
   10    *      http://www.apache.org/licenses/LICENSE-2.0
   11    * 
   12    * Unless required by applicable law or agreed to in writing, software
   13    * distributed under the License is distributed on an "AS IS" BASIS,
   14    * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   15    * See the License for the specific language governing permissions and
   16    * limitations under the License.
   17    */
   18    
   19   package org.apache.struts.actions;
   20   
   21   import javax.servlet.RequestDispatcher;
   22   import javax.servlet.ServletException;
   23   import javax.servlet.http.HttpServletRequest;
   24   import javax.servlet.http.HttpServletResponse;
   25   
   26   import org.apache.struts.action.Action;
   27   import org.apache.struts.action.ActionForm;
   28   import org.apache.struts.action.ActionForward;
   29   import org.apache.struts.action.ActionMapping;
   30   import org.apache.struts.upload.MultipartRequestWrapper;
   31   import org.apache.struts.util.MessageResources;
   32   
   33   /**
   34    * <p>An <strong>Action</strong> that includes the context-relative
   35    * URI specified by the <code>parameter</code> property of our associated
   36    * <code>ActionMapping</code>.  This can be used to integrate Struts with
   37    * other business logic components that are implemented as servlets (or JSP
   38    * pages), but still take advantage of the Struts controller servlet's
   39    * functionality (such as processing of form beans).</p>
   40    *
   41    * <p>To configure the use of this Action in your
   42    * <code>struts-config.xml</code> file, create an entry like this:</p>
   43    *
   44    * <code>
   45    *   &lt;action path="/saveSubscription"
   46    *           type="org.apache.struts.actions.IncludeAction"
   47    *           name="subscriptionForm"
   48    *          scope="request"
   49    *          input="/subscription.jsp"
   50    *      parameter="/path/to/processing/servlet"&gt;
   51    * </code>
   52    *
   53    * <p>which will include the context-relative URI specified by the
   54    * <code>parameter</code> attribute.</p>
   55    *
   56    * @version $Rev: 54929 $ $Date: 2004-10-16 17:38:42 +0100 (Sat, 16 Oct 2004) $
   57    */
   58   public class IncludeAction extends Action {
   59   
   60   
   61       // ----------------------------------------------------- Instance Variables
   62   
   63   
   64       /**
   65        * The message resources for this package.
   66        */
   67       protected static MessageResources messages =
   68        MessageResources.getMessageResources
   69           ("org.apache.struts.actions.LocalStrings");
   70   
   71   
   72       // --------------------------------------------------------- Public Methods
   73   
   74   
   75       /**
   76        * Process the specified HTTP request, and create the corresponding HTTP
   77        * response (or forward to another web component that will create it).
   78        * Return an <code>ActionForward</code> instance describing where and how
   79        * control should be forwarded, or <code>null</code> if the response has
   80        * already been completed.
   81        *
   82        * @param mapping The ActionMapping used to select this instance
   83        * @param form The optional ActionForm bean for this request (if any)
   84        * @param request The HTTP request we are processing
   85        * @param response The HTTP response we are creating
   86        *
   87        * @exception Exception if an error occurs
   88        */
   89       public ActionForward execute(
   90           ActionMapping mapping,
   91           ActionForm form,
   92           HttpServletRequest request,
   93           HttpServletResponse response)
   94           throws Exception {
   95   
   96           // Create a RequestDispatcher the corresponding resource
   97           String path = mapping.getParameter();
   98           if (path == null) {
   99               throw new ServletException(messages.getMessage("include.path"));
  100           }
  101   
  102           RequestDispatcher rd =
  103               servlet.getServletContext().getRequestDispatcher(path);
  104   
  105           if (rd == null) {
  106               throw new ServletException(messages.getMessage("include.rd", path));
  107           }
  108   
  109           // Unwrap the multipart request, if there is one.
  110           if (request instanceof MultipartRequestWrapper) {
  111               request = ((MultipartRequestWrapper) request).getRequest();
  112           }
  113   
  114           // Forward control to the specified resource
  115           rd.include(request, response);
  116   
  117           // Tell the controller servlet that the response has been created
  118           return (null);
  119   
  120       }
  121   
  122   
  123   }
  124