1 /*
2 * Copyright 2003,2004 The Apache Software Foundation.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package org.apache.struts.chain;
18
19
20 import java.util.HashMap;
21 import java.util.Map;
22 import org.apache.commons.chain.Command;
23 import org.apache.commons.chain.Context;
24 import org.apache.commons.chain.web.WebContext;
25 import org.apache.struts.action.Action;
26 import org.apache.struts.action.ActionServlet;
27 import org.apache.struts.chain.Constants;
28 import org.apache.struts.chain.util.ClassUtils;
29 import org.apache.struts.config.ActionConfig;
30 import org.apache.struts.config.ModuleConfig;
31 import org.apache.commons.logging.Log;
32 import org.apache.commons.logging.LogFactory;
33
34
35 /**
36 * <p>Create (if necessary) and cache an <code>Action</code> for this request.
37 * </p>
38 *
39 * @author Craig R. McClanahan
40 * @version $Rev: 54933 $ $Date: 2004-10-16 18:04:52 +0100 (Sat, 16 Oct 2004) $
41 */
42
43 public class CreateAction implements Command {
44
45
46 // ------------------------------------------------------ Instance Variables
47 private static final Log log = LogFactory.getLog(CreateAction.class);
48
49 private String actionKey = Constants.ACTION_KEY;
50 private String actionConfigKey = Constants.ACTION_CONFIG_KEY;
51 private String actionServletKey = Constants.ACTION_SERVLET_KEY;
52 private String validKey = Constants.VALID_KEY;
53
54
55 // -------------------------------------------------------------- Properties
56
57
58 /**
59 * <p>Return the context attribute key under which the
60 * <code>Action</code> for the currently selected application
61 * action is stored.</p>
62 */
63 public String getActionKey() {
64
65 return (this.actionKey);
66
67 }
68
69
70 /**
71 * <p>Set the context attribute key under which the
72 * <code>Action</code> for the currently selected application
73 * action is stored.</p>
74 *
75 * @param actionKey The new context attribute key
76 */
77 public void setActionKey(String actionKey) {
78
79 this.actionKey = actionKey;
80
81 }
82
83
84 /**
85 * <p>Return the context attribute key under which the
86 * <code>ActionConfig</code> for the currently selected application
87 * action is stored.</p>
88 */
89 public String getActionConfigKey() {
90
91 return (this.actionConfigKey);
92
93 }
94
95
96 /**
97 * <p>Set the context attribute key under which the
98 * <code>ActionConfig</code> for the currently selected application
99 * action is stored.</p>
100 *
101 * @param actionConfigKey The new context attribute key
102 */
103 public void setActionConfigKey(String actionConfigKey) {
104
105 this.actionConfigKey = actionConfigKey;
106
107 }
108
109
110 /**
111 * <p>Return the context attribute key under which the
112 * <code>ActionServlet</code> for the current web application
113 * is stored.</p>
114 */
115 public String getActionServletKey() {
116
117 return (this.actionServletKey);
118
119 }
120
121
122 /**
123 * <p>Set the context attribute key under which the
124 * <code>ActionServlet</code> for the current web application
125 * is stored.</p>
126 *
127 * @param actionServletKey The new context attribute key
128 */
129 public void setActionServletKey(String actionServletKey) {
130
131 this.actionServletKey = actionServletKey;
132
133 }
134
135
136 /**
137 * <p>Return the context attribute key under which the
138 * validity flag for this request is stored.</p>
139 */
140 public String getValidKey() {
141
142 return (this.validKey);
143
144 }
145
146
147 /**
148 * <p>Set the context attribute key under which the
149 * validity flag for this request is stored.</p>
150 *
151 * @param validKey The new context attribute key
152 */
153 public void setValidKey(String validKey) {
154
155 this.validKey = validKey;
156
157 }
158
159
160 // ---------------------------------------------------------- Public Methods
161
162
163 /**
164 * <p>Create (if necessary) and cache an <code>Action</code> for this
165 * request.</p>
166 *
167 * @param context The <code>Context</code> for the current request
168 *
169 * @return <code>false</code> so that processing continues
170 */
171 public boolean execute(Context context) throws Exception {
172
173 // Skip processing if the current request is not valid
174 Boolean valid = (Boolean) context.get(getValidKey());
175 if ((valid == null) || !valid.booleanValue()) {
176 return (false);
177 }
178
179 // Check to see if an action has already been created
180 if (context.get(getActionKey()) != null) {
181 return (false);
182 }
183
184 // Look up the class name for the desired Action
185 ActionConfig actionConfig = (ActionConfig)
186 context.get(getActionConfigKey());
187 String type = actionConfig.getType();
188
189 if (type == null) {
190 return (false);
191 }
192
193 // Create (if necessary) and cache an Action instance
194 Action action = null;
195 Map actions = getActions(context, actionConfig.getModuleConfig());
196 synchronized (actions) {
197 action = (Action) actions.get(type);
198 if (action == null) {
199 log.info("Initialize action of type: " + type + " for actionConfig " + actionConfig);
200 action = (Action) ClassUtils.getApplicationInstance(type);
201 ActionServlet actionServlet = (ActionServlet)
202 context.get(getActionServletKey());
203 action.setServlet(actionServlet);
204 actions.put(type, action);
205 }
206 }
207 context.put(getActionKey(), action);
208
209 return (false);
210
211 }
212
213
214 // ------------------------------------------------------- Protected Methods
215
216
217 /**
218 * <p>Create (if necessary) and return a <code>Map</code> containing the
219 * <code>Action</code> instances for the current application module.</p>
220 *
221 * @param context The context for this request
222 * @param moduleConfig The <code>ModuleConfig</code> for the current
223 * application module
224 */
225 protected synchronized Map getActions(Context context,
226 ModuleConfig moduleConfig) {
227
228 WebContext wcontext = (WebContext) context;
229 String actionsKey = Constants.ACTIONS_KEY + moduleConfig.getPrefix();
230 Map actions = (Map) wcontext.getApplicationScope().get(actionsKey);
231 if (actions == null) {
232 actions = new HashMap();
233 wcontext.getApplicationScope().put(actionKey, actions);
234 }
235 return (actions);
236
237 }
238
239
240
241 }