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
22 package org.apache.struts.tiles.actions;
23
24 import java.io.IOException;
25 import java.io.PrintWriter;
26
27 import jakarta.servlet.http.HttpServletRequest;
28 import jakarta.servlet.http.HttpServletResponse;
29
30 import org.apache.struts.action.Action;
31 import org.apache.struts.action.ActionForm;
32 import org.apache.struts.action.ActionForward;
33 import org.apache.struts.action.ActionMapping;
34 import org.apache.struts.tiles.ComponentDefinition;
35 import org.apache.struts.tiles.DefinitionsFactoryException;
36 import org.apache.struts.tiles.FactoryNotFoundException;
37 import org.apache.struts.tiles.NoSuchDefinitionException;
38 import org.apache.struts.tiles.TilesUtil;
39 import org.slf4j.Logger;
40 import org.slf4j.LoggerFactory;
41
42 /**
43 * <p>An <strong>Action</strong> that dispatches to a Tiles Definition
44 * that is named by the request parameter whose name is specified
45 * by the <code>parameter</code> property of the corresponding
46 * ActionMapping.
47 * This action is useful in following situations:
48 * <li>
49 * <ul>To associate an Url to a definition</ul>
50 * <ul>To use Struts <html:link> tag on a definition</ul>
51 * </li>
52 * <p>To configure the use of this action in your
53 * <code>struts-config.xml</code> file, create an entry like this:</p>
54 *
55 * <code>
56 * <action path="/saveSubscription"
57 * type="org.apache.struts.tiles.actions.DefinitionDispatcherAction"
58 * parameter="def"/>
59 * <forward name="success" path="anything" //>
60 * <forward name="error" path="path.to.error.page" //>
61 * </code>
62 *
63 * <p>which will use the value of the request parameter named "def"
64 * to pick the appropriate definition name.
65 * <p> The value for success doesn't matter. The forward will forward to
66 * appropriate definition.
67 * <p> The value for error should denote a valid jsp path or definition name.
68 *
69 * @version $Rev$ $Date$
70 */
71 public class DefinitionDispatcherAction extends Action {
72 private static final long serialVersionUID = 8663194696860741591L;
73
74 /**
75 * The {@code Log} instance for this class.
76 */
77 private transient final Logger log =
78 LoggerFactory.getLogger(DefinitionDispatcherAction.class);
79
80 /**
81 * Process the specified HTTP request, and create the corresponding HTTP
82 * response (or forward to another web component that will create it),
83 * with provision for handling exceptions thrown by the business logic.
84 *
85 * @param mapping The ActionMapping used to select this instance
86 * @param form The optional ActionForm bean for this request (if any)
87 * @param request The HTTP request we are processing
88 * @param response The HTTP response we are creating
89 *
90 * @exception Exception if the application business logic throws
91 * an exception
92 * @since Struts 1.1
93 */
94 @SuppressWarnings("deprecation")
95 public ActionForward execute(
96 ActionMapping mapping,
97 ActionForm form,
98 HttpServletRequest request,
99 HttpServletResponse response)
100 throws Exception {
101
102 // Identify the request parameter containing the method name
103 // If none defined, use "def"
104 String parameter = mapping.getParameter();
105 if (parameter == null) {
106 parameter = "def";
107 }
108
109 // Identify the method name to be dispatched to
110 String name = request.getParameter(parameter);
111 if (name == null) {
112 log.error("Can't get parameter '{}'.", parameter);
113
114 return mapping.findForward("error");
115 }
116
117 // Try to dispatch to requested definition
118 try {
119 // Read definition from factory, but we can create it here.
120 ComponentDefinition definition =
121 TilesUtil.getDefinition(
122 name,
123 request,
124 getServlet().getServletContext());
125
126 log.debug("Get Definition {}", definition);
127
128 org.apache.struts.tiles.DefinitionsUtil.setActionDefinition(request, definition);
129
130 } catch (FactoryNotFoundException e) {
131 log.error("Can't get definition factory.", e);
132 return mapping.findForward("error");
133
134 } catch (NoSuchDefinitionException e) {
135 log.error("Can't get definition '{}'.", name, e);
136 return mapping.findForward("error");
137
138 } catch (DefinitionsFactoryException e) {
139 log.error("General Factory error '{}'.", e.getMessage(), e);
140 return mapping.findForward("error");
141
142 } catch (Exception e) {
143 log.error("General error '{}'.", e.getMessage(), e);
144 return mapping.findForward("error");
145 }
146
147 return mapping.findForward("success");
148
149 }
150
151 /**
152 * @deprecated This will be removed after Struts 1.2.
153 */
154 @Deprecated
155 protected void printError(HttpServletResponse response, String msg)
156 throws IOException {
157 response.setContentType("text/plain");
158 PrintWriter writer = response.getWriter();
159 writer.println(msg);
160 writer.flush();
161 writer.close();
162 }
163 }