View Javadoc

1   /*
2    * $Id: DefinitionsUtil.java 421151 2006-07-12 06:07:14Z wsmoak $
3    *
4    * Copyright 1999-2004 The Apache Software Foundation.
5    *
6    * Licensed under the Apache License, Version 2.0 (the "License");
7    * you may not use this file except in compliance with the License.
8    * You may obtain a copy of the License at
9    *
10   *      http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing, software
13   * distributed under the License is distributed on an "AS IS" BASIS,
14   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15   * See the License for the specific language governing permissions and
16   * limitations under the License.
17   */
18  
19  package org.apache.struts.tiles;
20  
21  import java.lang.reflect.InvocationTargetException;
22  import java.util.Enumeration;
23  import java.util.HashMap;
24  import java.util.Map;
25  
26  import javax.servlet.ServletConfig;
27  import javax.servlet.ServletContext;
28  import javax.servlet.ServletRequest;
29  
30  import org.apache.commons.logging.Log;
31  import org.apache.commons.logging.LogFactory;
32  import org.apache.struts.tiles.taglib.ComponentConstants;
33  
34  /***
35   * Utilities class for definitions factory.
36   * Also define userDebugLevel property (TODO to be moved from this class ?).
37   * @deprecated Use {@link TilesUtil#createDefinitionsFactory(ServletContext, DefinitionsFactoryConfig)}
38   */
39  public class DefinitionsUtil extends TilesUtil implements ComponentConstants {
40  
41      /***
42       * Commons Logging instance.
43       */
44      protected static Log log = LogFactory.getLog(DefinitionsUtil.class);
45  
46      /***
47       * Global user defined debug level.
48       * @deprecated This will be removed in a release after Struts 1.2.
49       */
50      public static int userDebugLevel = 0;
51  
52      /***
53       * User Debug level.
54       * @deprecated This will be removed in a release after Struts 1.2.
55       */
56      public static final int NO_DEBUG = 0;
57  
58      /***
59       * Name of init property carrying debug level.
60       */
61      public static final String DEFINITIONS_CONFIG_USER_DEBUG_LEVEL =
62          "definitions-debug";
63  
64      /***
65       * Name of init property carrying factory class name.
66       */
67      public static final String DEFINITIONS_FACTORY_CLASSNAME =
68          "definitions-factory-class";
69  
70      /***
71       * Constant name used to store factory in context.
72       */
73      public static final String DEFINITIONS_FACTORY =
74          "org.apache.struts.tiles.DEFINITIONS_FACTORY";
75  
76      /***
77       * Constant name used to store definition in jsp context.
78       * Used to pass definition from a Struts action to servlet forward.
79       */
80      public static final String ACTION_DEFINITION =
81          "org.apache.struts.tiles.ACTION_DEFINITION";
82  
83      /***
84       * Create Definition factory.
85       * If a factory class name is provided, a factory of this class is created. Otherwise,
86       * default factory is created.
87       * @param classname Class name of the factory to create.
88       * @param servletContext Servlet Context passed to newly created factory.
89       * @param properties Map of name/property used to initialize factory configuration object.
90       * @return newly created factory.
91       * @throws DefinitionsFactoryException If an error occur while initializing factory
92       * @deprecated Use createDefinitionsFactory(ServletContext servletContext, ServletConfig servletConfig)
93       */
94      public static DefinitionsFactory createDefinitionsFactory(
95          ServletContext servletContext,
96          Map properties,
97          String classname)
98          throws DefinitionsFactoryException {
99  
100         // Create config object
101         DefinitionsFactoryConfig factoryConfig = new DefinitionsFactoryConfig();
102         // populate it from map.
103         try {
104             factoryConfig.populate(properties);
105 
106         } catch (Exception ex) {
107             throw new DefinitionsFactoryException(
108                 "Error - createDefinitionsFactory : Can't populate config object from properties map",
109                 ex);
110         }
111 
112         // Add classname
113         if (classname != null)
114             factoryConfig.setFactoryClassname(classname);
115 
116         // Create factory using config object
117         return createDefinitionsFactory(servletContext, factoryConfig);
118     }
119 
120     /***
121      * Create default Definition factory.
122      * @param servletContext Servlet Context passed to newly created factory.
123      * @param properties Map of name/property used to initialize factory configuration object.
124      * @return newly created factory of type ConfigurableDefinitionsFactory.
125      * @throws DefinitionsFactoryException If an error occur while initializing factory
126      */
127     public static DefinitionsFactory createDefinitionsFactory(
128         ServletContext servletContext,
129         Map properties)
130         throws DefinitionsFactoryException {
131 
132         return createDefinitionsFactory(servletContext, properties, null);
133     }
134 
135     /***
136      * Create Definition factory.
137      * Create configuration object from servlet web.xml file, then create
138      * ConfigurableDefinitionsFactory and initialized it with object.
139      * <p>
140      * Convenience method. Calls createDefinitionsFactory(ServletContext servletContext, DefinitionsFactoryConfig factoryConfig)
141      *
142      * @param servletContext Servlet Context passed to newly created factory.
143      * @param servletConfig Servlet config containing parameters to be passed to factory configuration object.
144      * @return newly created factory of type ConfigurableDefinitionsFactory.
145      * @throws DefinitionsFactoryException If an error occur while initializing factory
146      */
147     public static DefinitionsFactory createDefinitionsFactory(
148         ServletContext servletContext,
149         ServletConfig servletConfig)
150         throws DefinitionsFactoryException {
151 
152         DefinitionsFactoryConfig factoryConfig = readFactoryConfig(servletConfig);
153 
154         return createDefinitionsFactory(servletContext, factoryConfig);
155     }
156 
157     /***
158      * Create Definition factory.
159      * Create configuration object from servlet web.xml file, then create
160      * ConfigurableDefinitionsFactory and initialized it with object.
161      * <p>
162      * If checkIfExist is true, start by checking if factory already exist. If yes,
163      * return it. If no, create a new one.
164      * <p>
165      * If checkIfExist is false, factory is always created.
166      * <p>
167      * Convenience method. Calls createDefinitionsFactory(ServletContext servletContext, DefinitionsFactoryConfig factoryConfig)
168      *
169      * @param servletContext Servlet Context passed to newly created factory.
170      * @param servletConfig Servlet config containing parameters to be passed to factory configuration object.
171      * @param checkIfExist Check if factory already exist. If true and factory exist, return it.
172      * If true and factory doesn't exist, create it. If false, create it in all cases.
173      * @return newly created factory of type ConfigurableDefinitionsFactory.
174      * @throws DefinitionsFactoryException If an error occur while initializing factory
175      */
176     public static DefinitionsFactory createDefinitionsFactory(
177         ServletContext servletContext,
178         ServletConfig servletConfig,
179         boolean checkIfExist)
180         throws DefinitionsFactoryException {
181 
182         if (checkIfExist) {
183             // Check if already exist in context
184             DefinitionsFactory factory = getDefinitionsFactory(servletContext);
185             if (factory != null)
186                 return factory;
187         }
188 
189         return createDefinitionsFactory(servletContext, servletConfig);
190     }
191 
192     /***
193      * Get definition factory from appropriate servlet context.
194      * @return Definitions factory or null if not found.
195      * @deprecated Use {@link TilesUtil#getDefinitionsFactory(ServletRequest, ServletContext)}
196      * @since 20020708
197      */
198     public static DefinitionsFactory getDefinitionsFactory(ServletContext servletContext) {
199         return (DefinitionsFactory) servletContext.getAttribute(DEFINITIONS_FACTORY);
200     }
201 
202     /***
203      * Get Definition stored in jsp context by an action.
204      * @return ComponentDefinition or null if not found.
205      */
206     public static ComponentDefinition getActionDefinition(ServletRequest request) {
207         return (ComponentDefinition) request.getAttribute(ACTION_DEFINITION);
208     }
209 
210     /***
211      * Store definition in jsp context.
212      * Mainly used by Struts to pass a definition defined in an Action to the forward.
213      */
214     public static void setActionDefinition(
215         ServletRequest request,
216         ComponentDefinition definition) {
217 
218         request.setAttribute(ACTION_DEFINITION, definition);
219     }
220 
221     /***
222      * Remove Definition stored in jsp context.
223      * Mainly used by Struts to pass a definition defined in an Action to the forward.
224      */
225     public static void removeActionDefinition(
226         ServletRequest request,
227         ComponentDefinition definition) {
228 
229         request.removeAttribute(ACTION_DEFINITION);
230     }
231 
232     /***
233      * Populate Definition Factory Config from web.xml properties.
234      * @param factoryConfig Definition Factory Config to populate.
235      * @param servletConfig Current servlet config containing web.xml properties.
236      * @exception IllegalAccessException if the caller does not have
237      *  access to the property accessor method
238      * @exception java.lang.reflect.InvocationTargetException if the property accessor method
239      *  throws an exception
240      * @see org.apache.commons.beanutils.BeanUtils
241      * @since tiles 20020708
242      */
243     public static void populateDefinitionsFactoryConfig(
244         DefinitionsFactoryConfig factoryConfig,
245         ServletConfig servletConfig)
246         throws IllegalAccessException, InvocationTargetException {
247 
248         Map properties = new DefinitionsUtil.ServletPropertiesMap(servletConfig);
249         factoryConfig.populate(properties);
250     }
251 
252     /***
253      * Create FactoryConfig and initialize it from web.xml.
254      *
255      * @param servletConfig ServletConfig for the module with which
256      *  this plug in is associated
257      * @exception DefinitionsFactoryException if this <code>PlugIn</code> cannot
258      *  be successfully initialized
259      */
260     protected static DefinitionsFactoryConfig readFactoryConfig(ServletConfig servletConfig)
261         throws DefinitionsFactoryException {
262 
263         // Create tiles definitions config object
264         DefinitionsFactoryConfig factoryConfig = new DefinitionsFactoryConfig();
265 
266         // Get init parameters from web.xml files
267         try {
268             DefinitionsUtil.populateDefinitionsFactoryConfig(
269                 factoryConfig,
270                 servletConfig);
271 
272         } catch (Exception ex) {
273             ex.printStackTrace();
274             throw new DefinitionsFactoryException(
275                 "Can't populate DefinitionsFactoryConfig class from 'web.xml'.",
276                 ex);
277         }
278 
279         return factoryConfig;
280     }
281 
282     /***
283      * Inner class.
284      * Wrapper for ServletContext init parameters.
285      * Object of this class is an hashmap containing parameters and values
286      * defined in the servlet config file (web.xml).
287      */
288     static class ServletPropertiesMap extends HashMap {
289         /***
290          * Constructor.
291          */
292         ServletPropertiesMap(ServletConfig config) {
293             // This implementation is very simple.
294             // It is possible to avoid creation of a new structure, but this need
295             // imply writing all Map interface.
296             Enumeration e = config.getInitParameterNames();
297             while (e.hasMoreElements()) {
298                 String key = (String) e.nextElement();
299                 put(key, config.getInitParameter(key));
300             }
301         }
302     } // end inner class
303 
304 }