View Javadoc
1   /*
2    * $Id$
3    *
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *  http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing,
15   * software distributed under the License is distributed on an
16   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17   * KIND, either express or implied.  See the License for the
18   * specific language governing permissions and limitations
19   * under the License.
20   */
21  package org.apache.struts.extras.actions;
22  
23  import jakarta.servlet.RequestDispatcher;
24  import jakarta.servlet.ServletException;
25  import jakarta.servlet.http.HttpServletRequest;
26  import jakarta.servlet.http.HttpServletResponse;
27  
28  import org.apache.struts.action.ActionForm;
29  import org.apache.struts.action.ActionForward;
30  import org.apache.struts.action.ActionMapping;
31  
32  /**
33   * <p>An <strong>Action</strong> that includes the context-relative URI
34   * specified by the <code>parameter</code> property of our associated
35   * <code>ActionMapping</code>.  This can be used to integrate Struts with
36   * other business logic components that are implemented as servlets (or JSP
37   * pages), but still take advantage of the Struts controller servlet's
38   * functionality (such as processing of form beans).</p>
39   *
40   * <p>To configure the use of this Action in your <code>struts-config.xml</code>
41   * file, create an entry like this:</p>
42   *
43   * {@code &lt;action path="/saveSubscription"
44   * type="org.apache.struts.extras.actions.IncludeAction"
45   * name="subscriptionForm" scope="request" input="/subscription.jsp"
46   * parameter="/path/to/processing/servlet"&gt;}
47   *
48   * <p>which will include the context-relative URI specified by the
49   * <code>parameter</code> attribute.</p>
50   *
51   * @version $Rev$ $Date: 2005-11-09 00:11:45 -0500 (Wed, 09 Nov 2005)
52   *          $
53   */
54  public class IncludeAction extends BaseAction {
55      private static final long serialVersionUID = -6455723242287515520L;
56  
57      // ----------------------------------------------------- Instance Variables
58  
59      /**
60       * Process the specified HTTP request, and create the corresponding HTTP
61       * response (or forward to another web component that will create it).
62       * Return an <code>ActionForward</code> instance describing where and how
63       * control should be forwarded, or <code>null</code> if the response has
64       * already been completed.
65       *
66       * @param mapping  The ActionMapping used to select this instance
67       * @param form     The optional ActionForm bean for this request (if any)
68       * @param request  The HTTP request we are processing
69       * @param response The HTTP response we are creating
70       * @return The forward to which control should be transferred, or
71       *         <code>null</code> if the response has been completed.
72       * @throws Exception if an error occurs
73       */
74      public ActionForward execute(ActionMapping mapping, ActionForm form,
75          HttpServletRequest request, HttpServletResponse response)
76          throws Exception {
77          // Create a RequestDispatcher the corresponding resource
78          String path = mapping.getParameter();
79  
80          if (path == null) {
81              throw new ServletException(messages.getMessage("include.path"));
82          }
83  
84          RequestDispatcher rd =
85              servlet.getServletContext().getRequestDispatcher(path);
86  
87          if (rd == null) {
88              throw new ServletException(messages.getMessage("include.rd", path));
89          }
90  
91          // Forward control to the specified resource
92          rd.include(request, response);
93  
94          // Tell the controller servlet that the response has been created
95          return (null);
96      }
97  }