1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.chain.web.javax.servlet;
18
19 import java.util.Map;
20
21 import javax.servlet.ServletContext;
22 import javax.servlet.http.Cookie;
23 import javax.servlet.http.HttpServletRequest;
24 import javax.servlet.http.HttpServletResponse;
25
26 import org.apache.commons.chain.web.javax.WebContext;
27
28 /**
29 * Concrete implementation of {@link WebContext} suitable for use in
30 * Servlets and JSP pages. The abstract methods are mapped to the appropriate
31 * collections of the underlying servlet context, request, and response
32 * instances that are passed to the constructor (or the initialize method).
33 *
34 * @author Craig R. McClanahan
35 */
36 public class ServletWebContext extends WebContext {
37 private static final long serialVersionUID = 5302874006663111922L;
38
39 // ------------------------------------------------------ Instance Variables
40
41 /**
42 * The lazily instantiated {@code Map} of application scope
43 * attributes.
44 */
45 private transient Map<String, Object> applicationScope = null;
46
47 /**
48 * The {@code ServletContext} for this web application.
49 */
50 private transient ServletContext context = null;
51
52 /**
53 * The lazily instantiated {@code Map} of header name-value
54 * combinations (immutable).
55 */
56 private transient Map<String, String> header = null;
57
58 /**
59 * The lazily instantiated {@code Map} of header name-values
60 * combinations (immutable).
61 */
62 private transient Map<String, String[]> headerValues = null;
63
64 /**
65 * The lazily instantiated {@code Map} of context initialization
66 * parameters.
67 */
68 private transient Map<String, String> initParam = null;
69
70 /**
71 * The lazily instantiated {@code Map} of cookies.
72 */
73 private transient Map<String, Cookie> cookieValues = null;
74
75 /**
76 * The lazily instantiated {@code Map} of request
77 * parameter name-value.
78 */
79 private transient Map<String, String> param = null;
80
81 /**
82 * The lazily instantiated {@code Map} of request
83 * parameter name-values.
84 */
85 private transient Map<String, String[]> paramValues = null;
86
87 /**
88 * The {@code HttpServletRequest} for this request.
89 */
90 private transient HttpServletRequest request = null;
91
92 /**
93 * The lazily instantiated {@code Map} of request scope
94 * attributes.
95 */
96 private transient Map<String, Object> requestScope = null;
97
98 /**
99 * The {@code HttpServletResponse} for this request.
100 */
101 private transient HttpServletResponse response = null;
102
103 /**
104 * The lazily instantiated {@code Map} of session scope
105 * attributes.
106 */
107 private transient Map<String, Object> sessionScope = null;
108
109 // ------------------------------------------------------------ Constructors
110
111 /**
112 * Construct an uninitialized {@link ServletWebContext} instance.
113 */
114 public ServletWebContext() {
115 }
116
117 /**
118 * Construct a {@link ServletWebContext} instance that is initialized
119 * with the specified Servlet API objects.
120 *
121 * @param context The {@code ServletContext} for this web application
122 * @param request The {@code HttpServletRequest} for this request
123 * @param response The {@code HttpServletResponse} for this request
124 */
125 public ServletWebContext(ServletContext context,
126 HttpServletRequest request,
127 HttpServletResponse response) {
128
129 initialize(context, request, response);
130 }
131
132 // ---------------------------------------------------------- Public Methods
133
134 /**
135 * Return the {@link ServletContext} for this context.
136 *
137 * @return The {@code ServletContext} for this context.
138 */
139 public ServletContext getContext() {
140 return this.context;
141 }
142
143 /**
144 * Return the {@link HttpServletRequest} for this context.
145 *
146 * @return The {@code HttpServletRequest} for this context.
147 */
148 public HttpServletRequest getRequest() {
149 return this.request;
150 }
151
152 /**
153 * Return the {@link HttpServletResponse} for this context.
154 *
155 * @return The {@code HttpServletResponse} for this context.
156 */
157 public HttpServletResponse getResponse() {
158 return this.response;
159 }
160
161 /**
162 * Initialize (or reinitialize) this {@link ServletWebContext} instance
163 * for the specified Servlet API objects.
164 *
165 * @param context The {@code ServletContext} for this web application
166 * @param request The {@code HttpServletRequest} for this request
167 * @param response The {@code HttpServletResponse} for this request
168 */
169 public void initialize(ServletContext context,
170 HttpServletRequest request,
171 HttpServletResponse response) {
172
173 // Save the specified Servlet API object references
174 this.context = context;
175 this.request = request;
176 this.response = response;
177
178 // Perform other setup as needed
179 }
180
181 /**
182 * Release references to allocated resources acquired in
183 * {@code initialize()} of via subsequent processing. After this
184 * method is called, subsequent calls to any other method than
185 * {@code initialize()} will return undefined results.
186 */
187 public void release() {
188 // Release references to allocated collections
189 applicationScope = null;
190 header = null;
191 headerValues = null;
192 initParam = null;
193 param = null;
194 paramValues = null;
195 cookieValues = null;
196 requestScope = null;
197 sessionScope = null;
198
199 // Release references to Servlet API objects
200 context = null;
201 request = null;
202 response = null;
203 }
204
205 // ------------------------------------------------------ WebContext Methods
206
207 /**
208 * See the {@link WebContext}'s Javadoc.
209 *
210 * @return Application scope Map.
211 */
212 @Override
213 public Map<String, Object> getApplicationScope() {
214 if (applicationScope == null && context != null) {
215 applicationScope = new ServletApplicationScopeMap(context);
216 }
217 return applicationScope;
218 }
219
220 /**
221 * See the {@link WebContext}'s Javadoc.
222 *
223 * @return Header values Map.
224 */
225 @Override
226 public Map<String, String> getHeader() {
227 if (header == null && request != null) {
228 header = new ServletHeaderMap(request);
229 }
230 return header;
231 }
232
233 /**
234 * See the {@link WebContext}'s Javadoc.
235 *
236 * @return Header values Map.
237 */
238 @Override
239 public Map<String, String[]> getHeaderValues() {
240 if (headerValues == null && request != null) {
241 headerValues = new ServletHeaderValuesMap(request);
242 }
243 return headerValues;
244 }
245
246 /**
247 * See the {@link WebContext}'s Javadoc.
248 *
249 * @return Initialization parameter Map.
250 */
251 @Override
252 public Map<String, String> getInitParam() {
253 if (initParam == null && context != null) {
254 initParam = new ServletInitParamMap(context);
255 }
256 return initParam;
257 }
258
259 /**
260 * See the {@link WebContext}'s Javadoc.
261 *
262 * @return Request parameter Map.
263 */
264 @Override
265 public Map<String, String> getParam() {
266 if (param == null && request != null) {
267 param = new ServletParamMap(request);
268 }
269 return param;
270 }
271
272 /**
273 * See the {@link WebContext}'s Javadoc.
274 *
275 * @return Request parameter Map.
276 */
277 @Override
278 public Map<String, String[]> getParamValues() {
279 if (paramValues == null && request != null) {
280 paramValues = new ServletParamValuesMap(request);
281 }
282 return paramValues;
283 }
284
285 /**
286 * See the {@link WebContext}'s Javadoc.
287 *
288 * @return Map of Cookies.
289 * @since Chain 1.1
290 */
291 @Override
292 public Map<String, Cookie> getCookies() {
293 if (cookieValues == null && request != null) {
294 cookieValues = new ServletCookieMap(request);
295 }
296 return cookieValues;
297 }
298
299 /**
300 * See the {@link WebContext}'s Javadoc.
301 *
302 * @return Request scope Map.
303 */
304 @Override
305 public Map<String, Object> getRequestScope() {
306 if (requestScope == null && request != null) {
307 requestScope = new ServletRequestScopeMap(request);
308 }
309 return requestScope;
310 }
311
312 /**
313 * See the {@link WebContext}'s Javadoc.
314 *
315 * @return Session scope Map.
316 */
317 @Override
318 public Map<String, Object> getSessionScope() {
319 if (sessionScope == null && request != null) {
320 sessionScope = new ServletSessionScopeMap(request);
321 }
322 return sessionScope;
323 }
324 }