1 //
2 // ========================================================================
3 // Copyright (c) 1995-2013 Mort Bay Consulting Pty. Ltd.
4 // ------------------------------------------------------------------------
5 // All rights reserved. This program and the accompanying materials
6 // are made available under the terms of the Eclipse Public License v1.0
7 // and Apache License v2.0 which accompanies this distribution.
8 //
9 // The Eclipse Public License is available at
10 // http://www.eclipse.org/legal/epl-v10.html
11 //
12 // The Apache License v2.0 is available at
13 // http://www.opensource.org/licenses/apache2.0.php
14 //
15 // You may elect to redistribute this code under either of these licenses.
16 // ========================================================================
17 //
18
19 package org.eclipse.jetty.servlets.gzip;
20
21 import java.io.IOException;
22 import java.io.OutputStream;
23 import java.io.OutputStreamWriter;
24 import java.io.PrintWriter;
25 import java.io.UnsupportedEncodingException;
26 import java.util.HashSet;
27 import java.util.Set;
28 import java.util.StringTokenizer;
29 import java.util.zip.DeflaterOutputStream;
30 import java.util.zip.GZIPOutputStream;
31
32 import javax.servlet.ServletException;
33 import javax.servlet.http.HttpServletRequest;
34 import javax.servlet.http.HttpServletResponse;
35
36 import org.eclipse.jetty.continuation.Continuation;
37 import org.eclipse.jetty.continuation.ContinuationListener;
38 import org.eclipse.jetty.continuation.ContinuationSupport;
39 import org.eclipse.jetty.http.HttpMethod;
40 import org.eclipse.jetty.server.Request;
41 import org.eclipse.jetty.server.handler.HandlerWrapper;
42 import org.eclipse.jetty.util.log.Log;
43 import org.eclipse.jetty.util.log.Logger;
44
45 /* ------------------------------------------------------------ */
46 /**
47 * GZIP Handler This handler will gzip the content of a response if:
48 * <ul>
49 * <li>The filter is mapped to a matching path</li>
50 * <li>The response status code is >=200 and <300
51 * <li>The content length is unknown or more than the <code>minGzipSize</code> initParameter or the minGzipSize is 0(default)</li>
52 * <li>The content-type is in the comma separated list of mimeTypes set in the <code>mimeTypes</code> initParameter or if no mimeTypes are defined the
53 * content-type is not "application/gzip"</li>
54 * <li>No content-encoding is specified by the resource</li>
55 * </ul>
56 *
57 * <p>
58 * Compressing the content can greatly improve the network bandwidth usage, but at a cost of memory and CPU cycles. If this handler is used for static content,
59 * then use of efficient direct NIO may be prevented, thus use of the gzip mechanism of the <code>org.eclipse.jetty.servlet.DefaultServlet</code> is advised instead.
60 * </p>
61 */
62 public class GzipHandler extends HandlerWrapper
63 {
64 private static final Logger LOG = Log.getLogger(GzipHandler.class);
65
66 protected Set<String> _mimeTypes;
67 protected Set<String> _excluded;
68 protected int _bufferSize = 8192;
69 protected int _minGzipSize = 256;
70 protected String _vary = "Accept-Encoding, User-Agent";
71
72 /* ------------------------------------------------------------ */
73 /**
74 * Instantiates a new gzip handler.
75 */
76 public GzipHandler()
77 {
78 }
79
80 /* ------------------------------------------------------------ */
81 /**
82 * Get the mime types.
83 *
84 * @return mime types to set
85 */
86 public Set<String> getMimeTypes()
87 {
88 return _mimeTypes;
89 }
90
91 /* ------------------------------------------------------------ */
92 /**
93 * Set the mime types.
94 *
95 * @param mimeTypes
96 * the mime types to set
97 */
98 public void setMimeTypes(Set<String> mimeTypes)
99 {
100 _mimeTypes = mimeTypes;
101 }
102
103 /* ------------------------------------------------------------ */
104 /**
105 * Set the mime types.
106 *
107 * @param mimeTypes
108 * the mime types to set
109 */
110 public void setMimeTypes(String mimeTypes)
111 {
112 if (mimeTypes != null)
113 {
114 _mimeTypes = new HashSet<String>();
115 StringTokenizer tok = new StringTokenizer(mimeTypes,",",false);
116 while (tok.hasMoreTokens())
117 {
118 _mimeTypes.add(tok.nextToken());
119 }
120 }
121 }
122
123 /* ------------------------------------------------------------ */
124 /**
125 * Get the excluded user agents.
126 *
127 * @return excluded user agents
128 */
129 public Set<String> getExcluded()
130 {
131 return _excluded;
132 }
133
134 /* ------------------------------------------------------------ */
135 /**
136 * Set the excluded user agents.
137 *
138 * @param excluded
139 * excluded user agents to set
140 */
141 public void setExcluded(Set<String> excluded)
142 {
143 _excluded = excluded;
144 }
145
146 /* ------------------------------------------------------------ */
147 /**
148 * Set the excluded user agents.
149 *
150 * @param excluded
151 * excluded user agents to set
152 */
153 public void setExcluded(String excluded)
154 {
155 if (excluded != null)
156 {
157 _excluded = new HashSet<String>();
158 StringTokenizer tok = new StringTokenizer(excluded,",",false);
159 while (tok.hasMoreTokens())
160 _excluded.add(tok.nextToken());
161 }
162 }
163
164 /* ------------------------------------------------------------ */
165 /**
166 * @return The value of the Vary header set if a response can be compressed.
167 */
168 public String getVary()
169 {
170 return _vary;
171 }
172
173 /* ------------------------------------------------------------ */
174 /**
175 * Set the value of the Vary header sent with responses that could be compressed.
176 * <p>
177 * By default it is set to 'Accept-Encoding, User-Agent' since IE6 is excluded by
178 * default from the excludedAgents. If user-agents are not to be excluded, then
179 * this can be set to 'Accept-Encoding'. Note also that shared caches may cache
180 * many copies of a resource that is varied by User-Agent - one per variation of the
181 * User-Agent, unless the cache does some normalization of the UA string.
182 * @param vary The value of the Vary header set if a response can be compressed.
183 */
184 public void setVary(String vary)
185 {
186 _vary = vary;
187 }
188
189 /* ------------------------------------------------------------ */
190 /**
191 * Get the buffer size.
192 *
193 * @return the buffer size
194 */
195 public int getBufferSize()
196 {
197 return _bufferSize;
198 }
199
200 /* ------------------------------------------------------------ */
201 /**
202 * Set the buffer size.
203 *
204 * @param bufferSize
205 * buffer size to set
206 */
207 public void setBufferSize(int bufferSize)
208 {
209 _bufferSize = bufferSize;
210 }
211
212 /* ------------------------------------------------------------ */
213 /**
214 * Get the minimum reponse size.
215 *
216 * @return minimum reponse size
217 */
218 public int getMinGzipSize()
219 {
220 return _minGzipSize;
221 }
222
223 /* ------------------------------------------------------------ */
224 /**
225 * Set the minimum reponse size.
226 *
227 * @param minGzipSize
228 * minimum reponse size
229 */
230 public void setMinGzipSize(int minGzipSize)
231 {
232 _minGzipSize = minGzipSize;
233 }
234
235 /* ------------------------------------------------------------ */
236 /**
237 * @see org.eclipse.jetty.server.handler.HandlerWrapper#handle(java.lang.String, org.eclipse.jetty.server.Request, javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
238 */
239 @Override
240 public void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException
241 {
242 if (_handler!=null && isStarted())
243 {
244 String ae = request.getHeader("accept-encoding");
245 if (ae != null && ae.indexOf("gzip")>=0 && !response.containsHeader("Content-Encoding")
246 && !HttpMethod.HEAD.is(request.getMethod()))
247 {
248 if (_excluded!=null)
249 {
250 String ua = request.getHeader("User-Agent");
251 if (_excluded.contains(ua))
252 {
253 _handler.handle(target,baseRequest, request, response);
254 return;
255 }
256 }
257
258 final CompressedResponseWrapper wrappedResponse = newGzipResponseWrapper(request,response);
259
260 boolean exceptional=true;
261 try
262 {
263 _handler.handle(target, baseRequest, request, wrappedResponse);
264 exceptional=false;
265 }
266 finally
267 {
268 Continuation continuation = ContinuationSupport.getContinuation(request);
269 if (continuation.isSuspended() && continuation.isResponseWrapped())
270 {
271 continuation.addContinuationListener(new ContinuationListener()
272 {
273 public void onComplete(Continuation continuation)
274 {
275 try
276 {
277 wrappedResponse.finish();
278 }
279 catch(IOException e)
280 {
281 LOG.warn(e);
282 }
283 }
284
285 public void onTimeout(Continuation continuation)
286 {}
287 });
288 }
289 else if (exceptional && !response.isCommitted())
290 {
291 wrappedResponse.resetBuffer();
292 wrappedResponse.noCompression();
293 }
294 else
295 wrappedResponse.finish();
296 }
297 }
298 else
299 {
300 _handler.handle(target,baseRequest, request, response);
301 }
302 }
303 }
304
305 /**
306 * Allows derived implementations to replace ResponseWrapper implementation.
307 *
308 * @param request the request
309 * @param response the response
310 * @return the gzip response wrapper
311 */
312 protected CompressedResponseWrapper newGzipResponseWrapper(HttpServletRequest request, HttpServletResponse response)
313 {
314 return new CompressedResponseWrapper(request,response)
315 {
316 {
317 super.setMimeTypes(GzipHandler.this._mimeTypes);
318 super.setBufferSize(GzipHandler.this._bufferSize);
319 super.setMinCompressSize(GzipHandler.this._minGzipSize);
320 }
321
322 @Override
323 protected AbstractCompressedStream newCompressedStream(HttpServletRequest request,HttpServletResponse response) throws IOException
324 {
325 return new AbstractCompressedStream("gzip",request,this,_vary)
326 {
327 @Override
328 protected DeflaterOutputStream createStream() throws IOException
329 {
330 return new GZIPOutputStream(_response.getOutputStream(),_bufferSize);
331 }
332 };
333 }
334
335 @Override
336 protected PrintWriter newWriter(OutputStream out,String encoding) throws UnsupportedEncodingException
337 {
338 return GzipHandler.this.newWriter(out,encoding);
339 }
340 };
341 }
342
343 /**
344 * Allows derived implementations to replace PrintWriter implementation.
345 *
346 * @param out the out
347 * @param encoding the encoding
348 * @return the prints the writer
349 * @throws UnsupportedEncodingException
350 */
351 protected PrintWriter newWriter(OutputStream out,String encoding) throws UnsupportedEncodingException
352 {
353 return encoding==null?new PrintWriter(out):new PrintWriter(new OutputStreamWriter(out,encoding));
354 }
355 }