001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018 package compressionFilters;
019
020 import java.io.IOException;
021 import java.io.OutputStreamWriter;
022 import java.io.PrintWriter;
023
024 import javax.servlet.ServletOutputStream;
025 import javax.servlet.http.HttpServletResponse;
026 import javax.servlet.http.HttpServletResponseWrapper;
027
028 /**
029 * Implementation of <b>HttpServletResponseWrapper</b> that works with
030 * the CompressionServletResponseStream implementation..
031 *
032 * @author Amy Roh
033 * @author Dmitri Valdin
034 * @version $Revision: 664175 $, $Date: 2008-06-06 18:43:44 -0400 (Fri, 06 Jun 2008) $
035 */
036
037 public class CompressionServletResponseWrapper extends HttpServletResponseWrapper {
038
039 // ----------------------------------------------------- Constructor
040
041 /**
042 * Calls the parent constructor which creates a ServletResponse adaptor
043 * wrapping the given response object.
044 */
045
046 public CompressionServletResponseWrapper(HttpServletResponse response) {
047 super(response);
048 origResponse = response;
049 if (debug > 1) {
050 System.out.println("CompressionServletResponseWrapper constructor gets called");
051 }
052 }
053
054 // ----------------------------------------------------- Instance Variables
055
056 /**
057 * Original response
058 */
059
060 protected HttpServletResponse origResponse = null;
061
062 /**
063 * Descriptive information about this Response implementation.
064 */
065
066 protected static final String info = "CompressionServletResponseWrapper";
067
068 /**
069 * The ServletOutputStream that has been returned by
070 * <code>getOutputStream()</code>, if any.
071 */
072
073 protected ServletOutputStream stream = null;
074
075
076 /**
077 * The PrintWriter that has been returned by
078 * <code>getWriter()</code>, if any.
079 */
080
081 protected PrintWriter writer = null;
082
083 /**
084 * The threshold number to compress
085 */
086 protected int threshold = 0;
087
088 /**
089 * Debug level
090 */
091 private int debug = 0;
092
093 /**
094 * Content type
095 */
096 protected String contentType = null;
097
098 // --------------------------------------------------------- Public Methods
099
100
101 /**
102 * Set content type
103 */
104 public void setContentType(String contentType) {
105 if (debug > 1) {
106 System.out.println("setContentType to " + contentType);
107 }
108 this.contentType = contentType;
109 origResponse.setContentType(contentType);
110 }
111
112
113 /**
114 * Set threshold number
115 */
116 public void setCompressionThreshold(int threshold) {
117 if (debug > 1) {
118 System.out.println("setCompressionThreshold to " + threshold);
119 }
120 this.threshold = threshold;
121 }
122
123
124 /**
125 * Set debug level
126 */
127 public void setDebugLevel(int debug) {
128 this.debug = debug;
129 }
130
131
132 /**
133 * Create and return a ServletOutputStream to write the content
134 * associated with this Response.
135 *
136 * @throws IOException if an input/output error occurs
137 */
138 public ServletOutputStream createOutputStream() throws IOException {
139 if (debug > 1) {
140 System.out.println("createOutputStream gets called");
141 }
142
143 CompressionResponseStream stream = new CompressionResponseStream(origResponse);
144 stream.setDebugLevel(debug);
145 stream.setBuffer(threshold);
146
147 return stream;
148
149 }
150
151
152 /**
153 * Finish a response.
154 */
155 public void finishResponse() {
156 try {
157 if (writer != null) {
158 writer.close();
159 } else {
160 if (stream != null)
161 stream.close();
162 }
163 } catch (IOException e) {
164 }
165 }
166
167 // ------------------------------------------------ ServletResponse Methods
168
169
170 /**
171 * Flush the buffer and commit this response.
172 *
173 * @throws IOException if an input/output error occurs
174 */
175 public void flushBuffer() throws IOException {
176 if (debug > 1) {
177 System.out.println("flush buffer @ CompressionServletResponseWrapper");
178 }
179 ((CompressionResponseStream) stream).flush();
180
181 }
182
183 /**
184 * Return the servlet output stream associated with this Response.
185 *
186 * @throws IllegalStateException if <code>getWriter</code> has
187 * already been called for this response
188 * @throws IOException if an input/output error occurs
189 */
190 public ServletOutputStream getOutputStream() throws IOException {
191
192 if (writer != null)
193 throw new IllegalStateException("getWriter() has already been called for this response");
194
195 if (stream == null)
196 stream = createOutputStream();
197 if (debug > 1) {
198 System.out.println("stream is set to " + stream + " in getOutputStream");
199 }
200
201 return (stream);
202
203 }
204
205 /**
206 * Return the writer associated with this Response.
207 *
208 * @throws IllegalStateException if <code>getOutputStream</code> has
209 * already been called for this response
210 * @throws IOException if an input/output error occurs
211 */
212 public PrintWriter getWriter() throws IOException {
213
214 if (writer != null)
215 return (writer);
216
217 if (stream != null)
218 throw new IllegalStateException("getOutputStream() has already been called for this response");
219
220 stream = createOutputStream();
221 if (debug > 1) {
222 System.out.println("stream is set to " + stream + " in getWriter");
223 }
224 //String charset = getCharsetFromContentType(contentType);
225 String charEnc = origResponse.getCharacterEncoding();
226 if (debug > 1) {
227 System.out.println("character encoding is " + charEnc);
228 }
229 // HttpServletResponse.getCharacterEncoding() shouldn't return null
230 // according the spec, so feel free to remove that "if"
231 if (charEnc != null) {
232 writer = new PrintWriter(new OutputStreamWriter(stream, charEnc));
233 } else {
234 writer = new PrintWriter(stream);
235 }
236
237 return (writer);
238
239 }
240
241
242 public void setContentLength(int length) {
243 }
244
245
246 /**
247 * Returns character from content type. This method was taken from tomcat.
248 *
249 * @author rajo
250 */
251 private static String getCharsetFromContentType(String type) {
252
253 if (type == null) {
254 return null;
255 }
256 int semi = type.indexOf(";");
257 if (semi == -1) {
258 return null;
259 }
260 String afterSemi = type.substring(semi + 1);
261 int charsetLocation = afterSemi.indexOf("charset=");
262 if (charsetLocation == -1) {
263 return null;
264 } else {
265 String afterCharset = afterSemi.substring(charsetLocation + 8);
266 String encoding = afterCharset.trim();
267 return encoding;
268 }
269 }
270
271 }