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
017 package compressionFilters;
018
019 import java.io.IOException;
020 import java.io.OutputStream;
021 import java.io.OutputStreamWriter;
022 import java.io.PrintWriter;
023 import java.util.Locale;
024 import javax.servlet.ServletRequest;
025 import javax.servlet.ServletResponse;
026 import javax.servlet.ServletException;
027 import javax.servlet.ServletOutputStream;
028 import javax.servlet.ServletResponse;
029 import javax.servlet.ServletResponseWrapper;
030 import javax.servlet.http.HttpServletResponse;
031 import javax.servlet.http.HttpServletResponseWrapper;
032
033 /**
034 * Implementation of <b>HttpServletResponseWrapper</b> that works with
035 * the CompressionServletResponseStream implementation..
036 *
037 * @author Amy Roh
038 * @author Dmitri Valdin
039 * @version $Revision: 267129 $, $Date: 2004-03-18 08:40:35 -0800 (Thu, 18 Mar 2004) $
040 */
041
042 public class CompressionServletResponseWrapper extends HttpServletResponseWrapper {
043
044 // ----------------------------------------------------- Constructor
045
046 /**
047 * Calls the parent constructor which creates a ServletResponse adaptor
048 * wrapping the given response object.
049 */
050
051 public CompressionServletResponseWrapper(HttpServletResponse response) {
052 super(response);
053 origResponse = response;
054 if (debug > 1) {
055 System.out.println("CompressionServletResponseWrapper constructor gets called");
056 }
057 }
058
059
060 // ----------------------------------------------------- Instance Variables
061
062 /**
063 * Original response
064 */
065
066 protected HttpServletResponse origResponse = null;
067
068 /**
069 * Descriptive information about this Response implementation.
070 */
071
072 protected static final String info = "CompressionServletResponseWrapper";
073
074 /**
075 * The ServletOutputStream that has been returned by
076 * <code>getOutputStream()</code>, if any.
077 */
078
079 protected ServletOutputStream stream = null;
080
081
082 /**
083 * The PrintWriter that has been returned by
084 * <code>getWriter()</code>, if any.
085 */
086
087 protected PrintWriter writer = null;
088
089 /**
090 * The threshold number to compress
091 */
092 protected int threshold = 0;
093
094 /**
095 * Debug level
096 */
097 private int debug = 0;
098
099 /**
100 * Content type
101 */
102 protected String contentType = null;
103
104 // --------------------------------------------------------- Public Methods
105
106
107 /**
108 * Set content type
109 */
110 public void setContentType(String contentType) {
111 if (debug > 1) {
112 System.out.println("setContentType to "+contentType);
113 }
114 this.contentType = contentType;
115 origResponse.setContentType(contentType);
116 }
117
118
119 /**
120 * Set threshold number
121 */
122 public void setCompressionThreshold(int threshold) {
123 if (debug > 1) {
124 System.out.println("setCompressionThreshold to " + threshold);
125 }
126 this.threshold = threshold;
127 }
128
129
130 /**
131 * Set debug level
132 */
133 public void setDebugLevel(int debug) {
134 this.debug = debug;
135 }
136
137
138 /**
139 * Create and return a ServletOutputStream to write the content
140 * associated with this Response.
141 *
142 * @exception IOException if an input/output error occurs
143 */
144 public ServletOutputStream createOutputStream() throws IOException {
145 if (debug > 1) {
146 System.out.println("createOutputStream gets called");
147 }
148
149 CompressionResponseStream stream = new CompressionResponseStream(origResponse);
150 stream.setDebugLevel(debug);
151 stream.setBuffer(threshold);
152
153 return stream;
154
155 }
156
157
158 /**
159 * Finish a response.
160 */
161 public void finishResponse() {
162 try {
163 if (writer != null) {
164 writer.close();
165 } else {
166 if (stream != null)
167 stream.close();
168 }
169 } catch (IOException e) {
170 }
171 }
172
173
174 // ------------------------------------------------ ServletResponse Methods
175
176
177 /**
178 * Flush the buffer and commit this response.
179 *
180 * @exception IOException if an input/output error occurs
181 */
182 public void flushBuffer() throws IOException {
183 if (debug > 1) {
184 System.out.println("flush buffer @ CompressionServletResponseWrapper");
185 }
186 ((CompressionResponseStream)stream).flush();
187
188 }
189
190 /**
191 * Return the servlet output stream associated with this Response.
192 *
193 * @exception IllegalStateException if <code>getWriter</code> has
194 * already been called for this response
195 * @exception IOException if an input/output error occurs
196 */
197 public ServletOutputStream getOutputStream() throws IOException {
198
199 if (writer != null)
200 throw new IllegalStateException("getWriter() has already been called for this response");
201
202 if (stream == null)
203 stream = createOutputStream();
204 if (debug > 1) {
205 System.out.println("stream is set to "+stream+" in getOutputStream");
206 }
207
208 return (stream);
209
210 }
211
212 /**
213 * Return the writer associated with this Response.
214 *
215 * @exception IllegalStateException if <code>getOutputStream</code> has
216 * already been called for this response
217 * @exception IOException if an input/output error occurs
218 */
219 public PrintWriter getWriter() throws IOException {
220
221 if (writer != null)
222 return (writer);
223
224 if (stream != null)
225 throw new IllegalStateException("getOutputStream() has already been called for this response");
226
227 stream = createOutputStream();
228 if (debug > 1) {
229 System.out.println("stream is set to "+stream+" in getWriter");
230 }
231 //String charset = getCharsetFromContentType(contentType);
232 String charEnc = origResponse.getCharacterEncoding();
233 if (debug > 1) {
234 System.out.println("character encoding is " + charEnc);
235 }
236 // HttpServletResponse.getCharacterEncoding() shouldn't return null
237 // according the spec, so feel free to remove that "if"
238 if (charEnc != null) {
239 writer = new PrintWriter(new OutputStreamWriter(stream, charEnc));
240 } else {
241 writer = new PrintWriter(stream);
242 }
243
244 return (writer);
245
246 }
247
248
249 public void setContentLength(int length) {
250 }
251
252
253 /**
254 * Returns character from content type. This method was taken from tomcat.
255 * @author rajo
256 */
257 private static String getCharsetFromContentType(String type) {
258
259 if (type == null) {
260 return null;
261 }
262 int semi = type.indexOf(";");
263 if (semi == -1) {
264 return null;
265 }
266 String afterSemi = type.substring(semi + 1);
267 int charsetLocation = afterSemi.indexOf("charset=");
268 if(charsetLocation == -1) {
269 return null;
270 } else {
271 String afterCharset = afterSemi.substring(charsetLocation + 8);
272 String encoding = afterCharset.trim();
273 return encoding;
274 }
275 }
276
277 }