KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > apache > commons > chain > web > servlet > ServletWebContext


1 /*
2  * Copyright 1999-2004 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 package org.apache.commons.chain.web.servlet;
17
18
19 import java.util.Map JavaDoc;
20 import javax.servlet.ServletContext JavaDoc;
21 import javax.servlet.http.HttpServletRequest JavaDoc;
22 import javax.servlet.http.HttpServletResponse JavaDoc;
23 import org.apache.commons.chain.web.WebContext;
24
25
26 /**
27  * <p>Concrete implementation of {@link WebContext} suitable for use in
28  * Servlets and JSP pages. The abstract methods are mapped to the appropriate
29  * collections of the underlying servlet context, request, and response
30  * instances that are passed to the constructor (or the initialize method).</p>
31  *
32  * @author Craig R. McClanahan
33  * @version $Revision: 1.5 $ $Date: 2004/02/25 00:01:04 $
34  */
35
36 public class ServletWebContext extends WebContext {
37
38
39     // ------------------------------------------------------------ Constructors
40
41
42     /**
43      * <p>Construct an uninitialized {@link ServletWebContext} instance.</p>
44      */
45     public ServletWebContext() {
46
47         ;
48
49     }
50
51
52     /**
53      * <p>Construct a {@link ServletWebContext} instance that is initialized
54      * with the specified Servlet API objects.</p>
55      *
56      * @param context The <code>ServletContext</code> for this web application
57      * @param request The <code>HttpServletRequest</code> for this request
58      * @param response The <code>HttpServletResponse</code> for this request
59      */
60     public ServletWebContext(ServletContext JavaDoc context,
61                              HttpServletRequest JavaDoc request,
62                              HttpServletResponse JavaDoc response) {
63
64         initialize(context, request, response);
65
66     }
67
68
69     // ------------------------------------------------------ Instance Variables
70
71
72     /**
73      * <p>The lazily instantiated <code>Map</code> of application scope
74      * attributes.</p>
75      */
76     private Map JavaDoc applicationScope = null;
77
78
79     /**
80      * <p>The <code>ServletContext</code> for this web application.</p>
81      */
82     protected ServletContext JavaDoc context = null;
83
84
85     /**
86      * <p>The lazily instantiated <code>Map</code> of header name-value
87      * combinations (immutable).</p>
88      */
89     private Map JavaDoc header = null;
90
91
92     /**
93      * <p>The lazily instantitated <code>Map</code> of header name-values
94      * combinations (immutable).</p>
95      */
96     private Map JavaDoc headerValues = null;
97
98
99     /**
100      * <p>The lazily instantiated <code>Map</code> of context initialization
101      * parameters.</p>
102      */
103     private Map JavaDoc initParam = null;
104
105
106     /**
107      * <p>The lazily instantiated <code>Map</code> of request
108      * parameter name-value.</p>
109      */
110     private Map JavaDoc param = null;
111
112
113     /**
114      * <p>The lazily instantiated <code>Map</code> of request
115      * parameter name-values.</p>
116      */
117     private Map JavaDoc paramValues = null;
118
119
120     /**
121      * <p>The <code>HttpServletRequest</code> for this request.</p>
122      */
123     protected HttpServletRequest JavaDoc request = null;
124
125
126     /**
127      * <p>The lazily instantiated <code>Map</code> of request scope
128      * attributes.</p>
129      */
130     private Map JavaDoc requestScope = null;
131
132
133     /**
134      * <p>The <code>HttpServletResponse</code> for this request.</p>
135      */
136     protected HttpServletResponse JavaDoc response = null;
137
138
139     /**
140      * <p>The lazily instantiated <code>Map</code> of session scope
141      * attributes.</p>
142      */
143     private Map JavaDoc sessionScope = null;
144
145
146     // ---------------------------------------------------------- Public Methods
147
148
149     /**
150      * <p>Return the {@link ServletContext} for this context.</p>
151      */
152     public ServletContext JavaDoc getContext() {
153
154     return (this.context);
155
156     }
157
158
159     /**
160      * <p>Return the {@link HttpServletRequest} for this context.</p>
161      */
162     public HttpServletRequest JavaDoc getRequest() {
163
164     return (this.request);
165
166     }
167
168
169     /**
170      * <p>Return the {@link HttpServletResponse} for this context.</p>
171      */
172     public HttpServletResponse JavaDoc getResponse() {
173
174     return (this.response);
175
176     }
177
178
179     /**
180      * <p>Initialize (or reinitialize) this {@link ServletWebContext} instance
181      * for the specified Servlet API objects.</p>
182      *
183      * @param context The <code>ServletContext</code> for this web application
184      * @param request The <code>HttpServletRequest</code> for this request
185      * @param response The <code>HttpServletResponse</code> for this request
186      */
187     public void initialize(ServletContext JavaDoc context,
188                            HttpServletRequest JavaDoc request,
189                            HttpServletResponse JavaDoc response) {
190
191         // Save the specified Servlet API object references
192 this.context = context;
193         this.request = request;
194         this.response = response;
195
196         // Perform other setup as needed
197
198     }
199
200
201     /**
202      * <p>Release references to allocated resources acquired in
203      * <code>initialize()</code> of via subsequent processing. After this
204      * method is called, subsequent calls to any other method than
205      * <code>initialize()</code> will return undefined results.</p>
206      */
207     public void release() {
208
209         // Release references to allocated collections
210 applicationScope = null;
211         header = null;
212         headerValues = null;
213         initParam = null;
214         param = null;
215         paramValues = null;
216         requestScope = null;
217         sessionScope = null;
218
219         // Release references to Servlet API objects
220 context = null;
221         request = null;
222         response = null;
223
224     }
225
226
227
228     // ------------------------------------------------------ WebContext Methods
229
230
231     public Map JavaDoc getApplicationScope() {
232
233         if ((applicationScope == null) && (context != null)) {
234             applicationScope = new ServletApplicationScopeMap(context);
235         }
236         return (applicationScope);
237
238     }
239
240
241     public Map JavaDoc getHeader() {
242
243         if ((header == null) && (request != null)) {
244             header = new ServletHeaderMap(request);
245         }
246         return (header);
247
248     }
249
250
251     public Map JavaDoc getHeaderValues() {
252
253         if ((headerValues == null) && (request != null)) {
254             headerValues = new ServletHeaderValuesMap(request);
255         }
256         return (headerValues);
257
258     }
259
260
261     public Map JavaDoc getInitParam() {
262
263         if ((initParam == null) && (context != null)) {
264             initParam = new ServletInitParamMap(context);
265         }
266         return (initParam);
267
268     }
269
270
271     public Map JavaDoc getParam() {
272
273         if ((param == null) && (request != null)) {
274             param = new ServletParamMap(request);
275         }
276         return (param);
277
278     }
279
280
281     public Map JavaDoc getParamValues() {
282
283         if ((paramValues == null) && (request != null)) {
284             paramValues = new ServletParamValuesMap(request);
285         }
286         return (paramValues);
287
288     }
289
290
291     public Map JavaDoc getRequestScope() {
292
293         if ((requestScope == null) && (request != null)) {
294             requestScope = new ServletRequestScopeMap(request);
295         }
296         return (requestScope);
297
298     }
299
300
301     public Map JavaDoc getSessionScope() {
302
303         if ((sessionScope == null) && (request != null)) {
304             sessionScope = new ServletSessionScopeMap(request.getSession());
305         }
306         return (sessionScope);
307
308     }
309
310
311
312 }
313
Popular Tags