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 org.apache.commons.beanutils.DynaBean;
21 import org.apache.commons.chain.Command;
22 import org.apache.commons.chain.Context;
23 import org.apache.commons.chain.web.WebContext;
24 import org.apache.struts.action.ActionForm;
25 import org.apache.struts.action.ActionMapping;
26 import org.apache.struts.action.ActionServlet;
27 import org.apache.struts.action.DynaActionForm;
28 import org.apache.struts.action.DynaActionFormClass;
29 import org.apache.struts.chain.Constants;
30 import org.apache.struts.chain.util.ClassUtils;
31 import org.apache.struts.config.ActionConfig;
32 import org.apache.struts.config.FormBeanConfig;
33 import org.apache.struts.config.ModuleConfig;
34 import org.apache.commons.logging.Log;
35 import org.apache.commons.logging.LogFactory;
36
37
38 /**
39 * <p>Create (if necessary) and cache a form bean for this request.</p>
40 *
41 * @author Craig R. McClanahan
42 * @version $Rev: 54933 $ $Date: 2004-10-16 18:04:52 +0100 (Sat, 16 Oct 2004) $
43 */
44
45 public class CreateActionForm implements Command {
46
47
48 // ------------------------------------------------------ Instance Variables
49
50
51 private String actionConfigKey = Constants.ACTION_CONFIG_KEY;
52 private String actionFormKey = Constants.ACTION_FORM_KEY;
53 private String actionServletKey = Constants.ACTION_SERVLET_KEY;
54 private String moduleConfigKey = Constants.MODULE_CONFIG_KEY;
55
56 private static final Log log =
57 LogFactory.getLog(CreateActionForm.class);
58
59 // -------------------------------------------------------------- Properties
60
61
62 /**
63 * <p>Return the context attribute key under which the
64 * <code>ActionConfig</code> for the currently selected application
65 * action is stored.</p>
66 */
67 public String getActionConfigKey() {
68
69 return (this.actionConfigKey);
70
71 }
72
73
74 /**
75 * <p>Set the context attribute key under which the
76 * <code>ActionConfig</code> for the currently selected application
77 * action is stored.</p>
78 *
79 * @param actionConfigKey The new context attribute key
80 */
81 public void setActionConfigKey(String actionConfigKey) {
82
83 this.actionConfigKey = actionConfigKey;
84
85 }
86
87
88 /**
89 * <p>Return the context attribute key under which the
90 * <code>ActionForm</code> for the currently selected application
91 * action is stored.</p>
92 */
93 public String getActionFormKey() {
94
95 return (this.actionFormKey);
96
97 }
98
99
100 /**
101 * <p>Set the context attribute key under which the
102 * <code>ActionForm</code> for the currently selected application
103 * action is stored.</p>
104 *
105 * @param actionFormKey The new context attribute key
106 */
107 public void setActionFormKey(String actionFormKey) {
108
109 this.actionFormKey = actionFormKey;
110
111 }
112
113
114 /**
115 * <p>Return the context attribute key under which the
116 * <code>ActionServlet</code> for the currently selected application
117 * action is stored.</p>
118 */
119 public String getActionServletKey() {
120
121 return (this.actionServletKey);
122
123 }
124
125
126 /**
127 * <p>Set the context attribute key under which the
128 * <code>ActionServlet</code> for the currently selected application
129 * action is stored.</p>
130 *
131 * @param actionServletKey The new context attribute key
132 */
133 public void setActionServletKey(String actionServletKey) {
134
135 this.actionServletKey = actionServletKey;
136
137 }
138
139 /**
140 * <p>Return the context attribute key under which the
141 * <code>ModuleConfig</code> for the currently selected application
142 * module is stored.</p>
143 */
144 public String getModuleConfigKey() {
145
146 return (this.moduleConfigKey);
147
148 }
149
150
151 /**
152 * <p>Set the context attribute key under which the
153 * <code>ModuleConfig</code> for the currently selected application
154 * module is stored.</p>
155 *
156 * @param moduleConfigKey The new context attribute key
157 */
158 public void setModuleConfigKey(String moduleConfigKey) {
159
160 this.moduleConfigKey = moduleConfigKey;
161
162 }
163
164
165 // ---------------------------------------------------------- Public Methods
166
167
168 /**
169 * <p>Create (if necessary) and cache a form bean for this request.</p>
170 *
171 * @param context The <code>Context</code> for the current request
172 *
173 * @return <code>false</code> so that processing continues
174 */
175 public boolean execute(Context context) throws Exception {
176
177 // Is there a form bean associated with this ActionConfig?
178 ActionConfig actionConfig = (ActionConfig)
179 context.get(getActionConfigKey());
180 String name = actionConfig.getName();
181 if (name == null) {
182 context.remove(getActionFormKey());
183 return (false);
184 }
185
186 log.trace("Look up form-bean " + name);
187
188 // Look up the corresponding FormBeanConfig (if any)
189 FormBeanConfig formBeanConfig =
190 actionConfig.getModuleConfig().findFormBeanConfig(name);
191 if (formBeanConfig == null) {
192 log.warn("No FormBeanConfig found in module "
193 + actionConfig.getModuleConfig().getPrefix()
194 + " under name " + name);
195 context.remove(getActionFormKey());
196 return (false);
197 }
198
199 // Look up the session scope ActionForm instance (if any)
200 WebContext wcontext = (WebContext) context;
201 ActionForm instance = null;
202 if ("session".equals(actionConfig.getScope())) {
203 instance = (ActionForm)
204 wcontext.getSessionScope().get(actionConfig.getAttribute());
205 }
206
207 // Can we recycle the existing instance (if any)?
208 if (instance != null) {
209 log.trace("Found an instance in the session; test for reusability");
210 if (formBeanConfig.getDynamic()) {
211 String className =
212 ((DynaBean) instance).getDynaClass().getName();
213 if (className.equals(formBeanConfig.getName())) {
214 wcontext.put
215 (getActionFormKey(), instance);
216 /* It should already be in session scope
217 if ("session".equals(actionConfig.getScope())) {
218 wcontext.getSessionScope().put
219 (actionConfig.getAttribute(), instance);
220 }
221 */
222 log.debug("Using existing instance (dynamic)");
223 return (false);
224 }
225 } else {
226 try {
227 Class configClass =
228 ClassUtils.getApplicationClass
229 (formBeanConfig.getType());
230 if (configClass.isAssignableFrom(instance.getClass())) {
231 wcontext.put
232 (getActionFormKey(), instance);
233 /* It should already be in session scope
234 if ("session".equals(actionConfig.getScope())) {
235 wcontext.getSessionScope().put
236 (actionConfig.getAttribute(), instance);
237 }
238 */
239 log.debug("Using existing instance (non-dynamic)");
240 return (false);
241 }
242 } catch (Exception e) {
243 log.debug("Error testing existing instance for reusability; just create a new instance", e);
244 }
245 }
246 }
247
248 log.trace("Make a new instance of: " + formBeanConfig);
249 // Create a new form bean instance
250 if (formBeanConfig.getDynamic()) {
251 ModuleConfig moduleConfig = (ModuleConfig)
252 wcontext.get(getModuleConfigKey());
253 DynaActionFormClass dynaClass =
254 DynaActionFormClass.createDynaActionFormClass(formBeanConfig);
255 instance = (ActionForm) dynaClass.newInstance();
256 ((DynaActionForm) instance).initialize
257 ((ActionMapping) actionConfig);
258 } else {
259 instance = (ActionForm)
260 ClassUtils.getApplicationInstance(formBeanConfig.getType());
261 }
262
263 // Configure and cache the new instance
264 ActionServlet servlet = (ActionServlet)
265 wcontext.get(getActionServletKey());
266 instance.setServlet(servlet);
267 wcontext.put(getActionFormKey(), instance);
268 if ("session".equals(actionConfig.getScope())) {
269 wcontext.getSessionScope().put
270 (actionConfig.getAttribute(), instance);
271 } else if ("request".equals(actionConfig.getScope())) {
272 wcontext.getRequestScope().put
273 (actionConfig.getAttribute(), instance);
274 }
275
276 return (false);
277
278 }
279
280
281 }