001 /*
002 * Copyright 2004 The Apache Software Foundation
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016 package compressionFilters;
017
018 import java.io.IOException;
019 import java.io.OutputStream;
020 import java.io.OutputStreamWriter;
021 import java.io.PrintWriter;
022 import java.util.Locale;
023 import javax.servlet.ServletRequest;
024 import javax.servlet.ServletResponse;
025 import javax.servlet.ServletException;
026 import javax.servlet.ServletOutputStream;
027 import javax.servlet.ServletResponse;
028 import javax.servlet.ServletResponseWrapper;
029 import javax.servlet.http.HttpServletResponse;
030 import javax.servlet.http.HttpServletResponseWrapper;
031
032 /**
033 * Implementation of <b>HttpServletResponseWrapper</b> that works with
034 * the CompressionServletResponseStream implementation..
035 *
036 * @author Amy Roh
037 * @author Dmitri Valdin
038 * @version $Revision: 267129 $, $Date: 2004-03-18 08:40:35 -0800 (Thu, 18 Mar 2004) $
039 */
040
041 public class CompressionServletResponseWrapper extends HttpServletResponseWrapper {
042
043 // ----------------------------------------------------- Constructor
044
045 /**
046 * Calls the parent constructor which creates a ServletResponse adaptor
047 * wrapping the given response object.
048 */
049
050 public CompressionServletResponseWrapper(HttpServletResponse response) {
051 super(response);
052 origResponse = response;
053 if (debug > 1) {
054 System.out.println("CompressionServletResponseWrapper constructor gets called");
055 }
056 }
057
058
059 // ----------------------------------------------------- Instance Variables
060
061 /**
062 * Original response
063 */
064
065 protected HttpServletResponse origResponse = null;
066
067 /**
068 * Descriptive information about this Response implementation.
069 */
070
071 protected static final String info = "CompressionServletResponseWrapper";
072
073 /**
074 * The ServletOutputStream that has been returned by
075 * <code>getOutputStream()</code>, if any.
076 */
077
078 protected ServletOutputStream stream = null;
079
080
081 /**
082 * The PrintWriter that has been returned by
083 * <code>getWriter()</code>, if any.
084 */
085
086 protected PrintWriter writer = null;
087
088 /**
089 * The threshold number to compress
090 */
091 protected int threshold = 0;
092
093 /**
094 * Debug level
095 */
096 private int debug = 0;
097
098 /**
099 * Content type
100 */
101 protected String contentType = null;
102
103 // --------------------------------------------------------- Public Methods
104
105
106 /**
107 * Set content type
108 */
109 public void setContentType(String contentType) {
110 if (debug > 1) {
111 System.out.println("setContentType to "+contentType);
112 }
113 this.contentType = contentType;
114 origResponse.setContentType(contentType);
115 }
116
117
118 /**
119 * Set threshold number
120 */
121 public void setCompressionThreshold(int threshold) {
122 if (debug > 1) {
123 System.out.println("setCompressionThreshold to " + threshold);
124 }
125 this.threshold = threshold;
126 }
127
128
129 /**
130 * Set debug level
131 */
132 public void setDebugLevel(int debug) {
133 this.debug = debug;
134 }
135
136
137 /**
138 * Create and return a ServletOutputStream to write the content
139 * associated with this Response.
140 *
141 * @exception IOException if an input/output error occurs
142 */
143 public ServletOutputStream createOutputStream() throws IOException {
144 if (debug > 1) {
145 System.out.println("createOutputStream gets called");
146 }
147
148 CompressionResponseStream stream = new CompressionResponseStream(origResponse);
149 stream.setDebugLevel(debug);
150 stream.setBuffer(threshold);
151
152 return stream;
153
154 }
155
156
157 /**
158 * Finish a response.
159 */
160 public void finishResponse() {
161 try {
162 if (writer != null) {
163 writer.close();
164 } else {
165 if (stream != null)
166 stream.close();
167 }
168 } catch (IOException e) {
169 }
170 }
171
172
173 // ------------------------------------------------ ServletResponse Methods
174
175
176 /**
177 * Flush the buffer and commit this response.
178 *
179 * @exception IOException if an input/output error occurs
180 */
181 public void flushBuffer() throws IOException {
182 if (debug > 1) {
183 System.out.println("flush buffer @ CompressionServletResponseWrapper");
184 }
185 ((CompressionResponseStream)stream).flush();
186
187 }
188
189 /**
190 * Return the servlet output stream associated with this Response.
191 *
192 * @exception IllegalStateException if <code>getWriter</code> has
193 * already been called for this response
194 * @exception IOException if an input/output error occurs
195 */
196 public ServletOutputStream getOutputStream() throws IOException {
197
198 if (writer != null)
199 throw new IllegalStateException("getWriter() has already been called for this response");
200
201 if (stream == null)
202 stream = createOutputStream();
203 if (debug > 1) {
204 System.out.println("stream is set to "+stream+" in getOutputStream");
205 }
206
207 return (stream);
208
209 }
210
211 /**
212 * Return the writer associated with this Response.
213 *
214 * @exception IllegalStateException if <code>getOutputStream</code> has
215 * already been called for this response
216 * @exception IOException if an input/output error occurs
217 */
218 public PrintWriter getWriter() throws IOException {
219
220 if (writer != null)
221 return (writer);
222
223 if (stream != null)
224 throw new IllegalStateException("getOutputStream() has already been called for this response");
225
226 stream = createOutputStream();
227 if (debug > 1) {
228 System.out.println("stream is set to "+stream+" in getWriter");
229 }
230 //String charset = getCharsetFromContentType(contentType);
231 String charEnc = origResponse.getCharacterEncoding();
232 if (debug > 1) {
233 System.out.println("character encoding is " + charEnc);
234 }
235 // HttpServletResponse.getCharacterEncoding() shouldn't return null
236 // according the spec, so feel free to remove that "if"
237 if (charEnc != null) {
238 writer = new PrintWriter(new OutputStreamWriter(stream, charEnc));
239 } else {
240 writer = new PrintWriter(stream);
241 }
242
243 return (writer);
244
245 }
246
247
248 public void setContentLength(int length) {
249 }
250
251
252 /**
253 * Returns character from content type. This method was taken from tomcat.
254 * @author rajo
255 */
256 private static String getCharsetFromContentType(String type) {
257
258 if (type == null) {
259 return null;
260 }
261 int semi = type.indexOf(";");
262 if (semi == -1) {
263 return null;
264 }
265 String afterSemi = type.substring(semi + 1);
266 int charsetLocation = afterSemi.indexOf("charset=");
267 if(charsetLocation == -1) {
268 return null;
269 } else {
270 String afterCharset = afterSemi.substring(charsetLocation + 8);
271 String encoding = afterCharset.trim();
272 return encoding;
273 }
274 }
275
276 }