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.ServletException;
24 import jakarta.servlet.http.HttpServletRequest;
25 import jakarta.servlet.http.HttpServletResponse;
26
27 import org.apache.struts.Globals;
28 import org.apache.struts.action.ActionForm;
29 import org.apache.struts.action.ActionForward;
30 import org.apache.struts.action.ActionMapping;
31 import org.apache.struts.util.ModuleUtils;
32 import org.slf4j.Logger;
33 import org.slf4j.LoggerFactory;
34
35 /**
36 * <p>A standard <strong>Action</strong> that switches to a new module and
37 * then forwards control to a URI (specified in a number of possible ways)
38 * within the new module.</p>
39 *
40 * <p>Valid request parameters for this Action are:</p>
41 *
42 * <ul>
43 *
44 * <li><strong>page</strong> - Module-relative URI (beginning with "/") to
45 * which control should be forwarded after switching.</li>
46 *
47 * <li><strong>prefix</strong> - The module prefix (beginning with "/") of the
48 * module to which control should be switched. Use a zero-length string for
49 * the default module. The appropriate <code>ModuleConfig</code> object will
50 * be stored as a request attribute, so any subsequent logic will assume the
51 * new module.</li>
52 *
53 * </ul>
54 *
55 * @version $Rev$ $Date: 2005-05-14 21:27:02 -0400 (Sat, 14 May 2005)
56 * $
57 * @since Struts 1.1
58 */
59 public class SwitchAction extends BaseAction {
60 private static final long serialVersionUID = -8632296010034881915L;
61
62 // ----------------------------------------------------- Instance Variables
63
64 /**
65 * The {@code Log} instance for this class.
66 */
67 private transient final Logger log =
68 LoggerFactory.getLogger(SwitchAction.class);
69
70 /**
71 * Process the specified HTTP request, and create the corresponding HTTP
72 * response (or forward to another web component that will create it).
73 * Return an <code>ActionForward</code> instance describing where and how
74 * control should be forwarded, or <code>null</code> if the response has
75 * already been completed.
76 *
77 * @param mapping The ActionMapping used to select this instance
78 * @param form The optional ActionForm bean for this request (if any)
79 * @param request The HTTP request we are processing
80 * @param response The HTTP response we are creating
81 * @return Return an <code>ActionForward</code> instance describing where
82 * and how control should be forwarded, or <code>null</code> if
83 * the response has already been completed.
84 * @throws Exception if an exception occurs
85 */
86 public ActionForward execute(ActionMapping mapping, ActionForm form,
87 HttpServletRequest request, HttpServletResponse response)
88 throws Exception {
89 // Identify the request parameters controlling our actions
90 String page = request.getParameter("page");
91 String prefix = request.getParameter("prefix");
92
93 if ((page == null) || (prefix == null)) {
94 String message = messages.getMessage("switch.required");
95
96 log.error(message);
97 throw new ServletException(message);
98 }
99
100 // Switch to the requested module
101 ModuleUtils.getInstance().selectModule(prefix, request,
102 getServlet().getServletContext());
103
104 if (request.getAttribute(Globals.MODULE_KEY) == null) {
105 String message = messages.getMessage("switch.prefix", prefix);
106
107 log.error(message);
108 throw new ServletException(message);
109 }
110
111 // Forward control to the specified module-relative URI
112 return (new ActionForward(page));
113 }
114 }