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 javax.servlet.http;
017
018 import java.io.IOException;
019
020 import javax.servlet.ServletResponse;
021
022 /**
023 *
024 * Extends the {@link ServletResponse} interface to provide HTTP-specific
025 * functionality in sending a response. For example, it has methods
026 * to access HTTP headers and cookies.
027 *
028 * <p>The servlet container creates an <code>HttpServletResponse</code> object
029 * and passes it as an argument to the servlet's service methods
030 * (<code>doGet</code>, <code>doPost</code>, etc).
031 *
032 *
033 * @author Various
034 * @version $Version$
035 *
036 * @see javax.servlet.ServletResponse
037 *
038 */
039
040
041
042 public interface HttpServletResponse extends ServletResponse {
043
044 /**
045 * Adds the specified cookie to the response. This method can be called
046 * multiple times to set more than one cookie.
047 *
048 * @param cookie the Cookie to return to the client
049 *
050 */
051
052 public void addCookie(Cookie cookie);
053
054 /**
055 * Returns a boolean indicating whether the named response header
056 * has already been set.
057 *
058 * @param name the header name
059 * @return <code>true</code> if the named response header
060 * has already been set;
061 * <code>false</code> otherwise
062 */
063
064 public boolean containsHeader(String name);
065
066 /**
067 * Encodes the specified URL by including the session ID in it,
068 * or, if encoding is not needed, returns the URL unchanged.
069 * The implementation of this method includes the logic to
070 * determine whether the session ID needs to be encoded in the URL.
071 * For example, if the browser supports cookies, or session
072 * tracking is turned off, URL encoding is unnecessary.
073 *
074 * <p>For robust session tracking, all URLs emitted by a servlet
075 * should be run through this
076 * method. Otherwise, URL rewriting cannot be used with browsers
077 * which do not support cookies.
078 *
079 * @param url the url to be encoded.
080 * @return the encoded URL if encoding is needed;
081 * the unchanged URL otherwise.
082 */
083
084 public String encodeURL(String url);
085
086 /**
087 * Encodes the specified URL for use in the
088 * <code>sendRedirect</code> method or, if encoding is not needed,
089 * returns the URL unchanged. The implementation of this method
090 * includes the logic to determine whether the session ID
091 * needs to be encoded in the URL. Because the rules for making
092 * this determination can differ from those used to decide whether to
093 * encode a normal link, this method is separated from the
094 * <code>encodeURL</code> method.
095 *
096 * <p>All URLs sent to the <code>HttpServletResponse.sendRedirect</code>
097 * method should be run through this method. Otherwise, URL
098 * rewriting cannot be used with browsers which do not support
099 * cookies.
100 *
101 * @param url the url to be encoded.
102 * @return the encoded URL if encoding is needed;
103 * the unchanged URL otherwise.
104 *
105 * @see #sendRedirect
106 * @see #encodeUrl
107 */
108
109 public String encodeRedirectURL(String url);
110
111 /**
112 * @deprecated As of version 2.1, use encodeURL(String url) instead
113 *
114 * @param url the url to be encoded.
115 * @return the encoded URL if encoding is needed;
116 * the unchanged URL otherwise.
117 */
118
119 public String encodeUrl(String url);
120
121 /**
122 * @deprecated As of version 2.1, use
123 * encodeRedirectURL(String url) instead
124 *
125 * @param url the url to be encoded.
126 * @return the encoded URL if encoding is needed;
127 * the unchanged URL otherwise.
128 */
129
130 public String encodeRedirectUrl(String url);
131
132 /**
133 * Sends an error response to the client using the specified
134 * status. The server defaults to creating the
135 * response to look like an HTML-formatted server error page
136 * containing the specified message, setting the content type
137 * to "text/html", leaving cookies and other headers unmodified.
138 *
139 * If an error-page declaration has been made for the web application
140 * corresponding to the status code passed in, it will be served back in
141 * preference to the suggested msg parameter.
142 *
143 * <p>If the response has already been committed, this method throws
144 * an IllegalStateException.
145 * After using this method, the response should be considered
146 * to be committed and should not be written to.
147 *
148 * @param sc the error status code
149 * @param msg the descriptive message
150 * @exception IOException If an input or output exception occurs
151 * @exception IllegalStateException If the response was committed
152 */
153
154 public void sendError(int sc, String msg) throws IOException;
155
156 /**
157 * Sends an error response to the client using the specified status
158 * code and clearing the buffer.
159 * <p>If the response has already been committed, this method throws
160 * an IllegalStateException.
161 * After using this method, the response should be considered
162 * to be committed and should not be written to.
163 *
164 * @param sc the error status code
165 * @exception IOException If an input or output exception occurs
166 * @exception IllegalStateException If the response was committed
167 * before this method call
168 */
169
170 public void sendError(int sc) throws IOException;
171
172 /**
173 * Sends a temporary redirect response to the client using the
174 * specified redirect location URL. This method can accept relative URLs;
175 * the servlet container must convert the relative URL to an absolute URL
176 * before sending the response to the client. If the location is relative
177 * without a leading '/' the container interprets it as relative to
178 * the current request URI. If the location is relative with a leading
179 * '/' the container interprets it as relative to the servlet container root.
180 *
181 * <p>If the response has already been committed, this method throws
182 * an IllegalStateException.
183 * After using this method, the response should be considered
184 * to be committed and should not be written to.
185 *
186 * @param location the redirect location URL
187 * @exception IOException If an input or output exception occurs
188 * @exception IllegalStateException If the response was committed or
189 if a partial URL is given and cannot be converted into a valid URL
190 */
191
192 public void sendRedirect(String location) throws IOException;
193
194 /**
195 *
196 * Sets a response header with the given name and
197 * date-value. The date is specified in terms of
198 * milliseconds since the epoch. If the header had already
199 * been set, the new value overwrites the previous one. The
200 * <code>containsHeader</code> method can be used to test for the
201 * presence of a header before setting its value.
202 *
203 * @param name the name of the header to set
204 * @param date the assigned date value
205 *
206 * @see #containsHeader
207 * @see #addDateHeader
208 */
209
210 public void setDateHeader(String name, long date);
211
212 /**
213 *
214 * Adds a response header with the given name and
215 * date-value. The date is specified in terms of
216 * milliseconds since the epoch. This method allows response headers
217 * to have multiple values.
218 *
219 * @param name the name of the header to set
220 * @param date the additional date value
221 *
222 * @see #setDateHeader
223 */
224
225 public void addDateHeader(String name, long date);
226
227 /**
228 *
229 * Sets a response header with the given name and value.
230 * If the header had already been set, the new value overwrites the
231 * previous one. The <code>containsHeader</code> method can be
232 * used to test for the presence of a header before setting its
233 * value.
234 *
235 * @param name the name of the header
236 * @param value the header value If it contains octet string,
237 * it should be encoded according to RFC 2047
238 * (http://www.ietf.org/rfc/rfc2047.txt)
239 *
240 * @see #containsHeader
241 * @see #addHeader
242 */
243
244 public void setHeader(String name, String value);
245
246 /**
247 * Adds a response header with the given name and value.
248 * This method allows response headers to have multiple values.
249 *
250 * @param name the name of the header
251 * @param value the additional header value If it contains
252 * octet string, it should be encoded
253 * according to RFC 2047
254 * (http://www.ietf.org/rfc/rfc2047.txt)
255 *
256 * @see #setHeader
257 */
258
259 public void addHeader(String name, String value);
260
261 /**
262 * Sets a response header with the given name and
263 * integer value. If the header had already been set, the new value
264 * overwrites the previous one. The <code>containsHeader</code>
265 * method can be used to test for the presence of a header before
266 * setting its value.
267 *
268 * @param name the name of the header
269 * @param value the assigned integer value
270 *
271 * @see #containsHeader
272 * @see #addIntHeader
273 */
274
275 public void setIntHeader(String name, int value);
276
277 /**
278 * Adds a response header with the given name and
279 * integer value. This method allows response headers to have multiple
280 * values.
281 *
282 * @param name the name of the header
283 * @param value the assigned integer value
284 *
285 * @see #setIntHeader
286 */
287
288 public void addIntHeader(String name, int value);
289
290
291
292 /**
293 * Sets the status code for this response. This method is used to
294 * set the return status code when there is no error (for example,
295 * for the status codes SC_OK or SC_MOVED_TEMPORARILY). If there
296 * is an error, and the caller wishes to invoke an error-page defined
297 * in the web application, the <code>sendError</code> method should be used
298 * instead.
299 * <p> The container clears the buffer and sets the Location header, preserving
300 * cookies and other headers.
301 *
302 * @param sc the status code
303 *
304 * @see #sendError
305 */
306
307 public void setStatus(int sc);
308
309 /**
310 * @deprecated As of version 2.1, due to ambiguous meaning of the
311 * message parameter. To set a status code
312 * use <code>setStatus(int)</code>, to send an error with a description
313 * use <code>sendError(int, String)</code>.
314 *
315 * Sets the status code and message for this response.
316 *
317 * @param sc the status code
318 * @param sm the status message
319 */
320
321 public void setStatus(int sc, String sm);
322
323
324 /*
325 * Server status codes; see RFC 2068.
326 */
327
328 /**
329 * Status code (100) indicating the client can continue.
330 */
331
332 public static final int SC_CONTINUE = 100;
333
334
335 /**
336 * Status code (101) indicating the server is switching protocols
337 * according to Upgrade header.
338 */
339
340 public static final int SC_SWITCHING_PROTOCOLS = 101;
341
342 /**
343 * Status code (200) indicating the request succeeded normally.
344 */
345
346 public static final int SC_OK = 200;
347
348 /**
349 * Status code (201) indicating the request succeeded and created
350 * a new resource on the server.
351 */
352
353 public static final int SC_CREATED = 201;
354
355 /**
356 * Status code (202) indicating that a request was accepted for
357 * processing, but was not completed.
358 */
359
360 public static final int SC_ACCEPTED = 202;
361
362 /**
363 * Status code (203) indicating that the meta information presented
364 * by the client did not originate from the server.
365 */
366
367 public static final int SC_NON_AUTHORITATIVE_INFORMATION = 203;
368
369 /**
370 * Status code (204) indicating that the request succeeded but that
371 * there was no new information to return.
372 */
373
374 public static final int SC_NO_CONTENT = 204;
375
376 /**
377 * Status code (205) indicating that the agent <em>SHOULD</em> reset
378 * the document view which caused the request to be sent.
379 */
380
381 public static final int SC_RESET_CONTENT = 205;
382
383 /**
384 * Status code (206) indicating that the server has fulfilled
385 * the partial GET request for the resource.
386 */
387
388 public static final int SC_PARTIAL_CONTENT = 206;
389
390 /**
391 * Status code (300) indicating that the requested resource
392 * corresponds to any one of a set of representations, each with
393 * its own specific location.
394 */
395
396 public static final int SC_MULTIPLE_CHOICES = 300;
397
398 /**
399 * Status code (301) indicating that the resource has permanently
400 * moved to a new location, and that future references should use a
401 * new URI with their requests.
402 */
403
404 public static final int SC_MOVED_PERMANENTLY = 301;
405
406 /**
407 * Status code (302) indicating that the resource has temporarily
408 * moved to another location, but that future references should
409 * still use the original URI to access the resource.
410 *
411 * This definition is being retained for backwards compatibility.
412 * SC_FOUND is now the preferred definition.
413 */
414
415 public static final int SC_MOVED_TEMPORARILY = 302;
416
417 /**
418 * Status code (302) indicating that the resource reside
419 * temporarily under a different URI. Since the redirection might
420 * be altered on occasion, the client should continue to use the
421 * Request-URI for future requests.(HTTP/1.1) To represent the
422 * status code (302), it is recommended to use this variable.
423 */
424
425 public static final int SC_FOUND = 302;
426
427 /**
428 * Status code (303) indicating that the response to the request
429 * can be found under a different URI.
430 */
431
432 public static final int SC_SEE_OTHER = 303;
433
434 /**
435 * Status code (304) indicating that a conditional GET operation
436 * found that the resource was available and not modified.
437 */
438
439 public static final int SC_NOT_MODIFIED = 304;
440
441 /**
442 * Status code (305) indicating that the requested resource
443 * <em>MUST</em> be accessed through the proxy given by the
444 * <code><em>Location</em></code> field.
445 */
446
447 public static final int SC_USE_PROXY = 305;
448
449 /**
450 * Status code (307) indicating that the requested resource
451 * resides temporarily under a different URI. The temporary URI
452 * <em>SHOULD</em> be given by the <code><em>Location</em></code>
453 * field in the response.
454 */
455
456 public static final int SC_TEMPORARY_REDIRECT = 307;
457
458 /**
459 * Status code (400) indicating the request sent by the client was
460 * syntactically incorrect.
461 */
462
463 public static final int SC_BAD_REQUEST = 400;
464
465 /**
466 * Status code (401) indicating that the request requires HTTP
467 * authentication.
468 */
469
470 public static final int SC_UNAUTHORIZED = 401;
471
472 /**
473 * Status code (402) reserved for future use.
474 */
475
476 public static final int SC_PAYMENT_REQUIRED = 402;
477
478 /**
479 * Status code (403) indicating the server understood the request
480 * but refused to fulfill it.
481 */
482
483 public static final int SC_FORBIDDEN = 403;
484
485 /**
486 * Status code (404) indicating that the requested resource is not
487 * available.
488 */
489
490 public static final int SC_NOT_FOUND = 404;
491
492 /**
493 * Status code (405) indicating that the method specified in the
494 * <code><em>Request-Line</em></code> is not allowed for the resource
495 * identified by the <code><em>Request-URI</em></code>.
496 */
497
498 public static final int SC_METHOD_NOT_ALLOWED = 405;
499
500 /**
501 * Status code (406) indicating that the resource identified by the
502 * request is only capable of generating response entities which have
503 * content characteristics not acceptable according to the accept
504 * headers sent in the request.
505 */
506
507 public static final int SC_NOT_ACCEPTABLE = 406;
508
509 /**
510 * Status code (407) indicating that the client <em>MUST</em> first
511 * authenticate itself with the proxy.
512 */
513
514 public static final int SC_PROXY_AUTHENTICATION_REQUIRED = 407;
515
516 /**
517 * Status code (408) indicating that the client did not produce a
518 * request within the time that the server was prepared to wait.
519 */
520
521 public static final int SC_REQUEST_TIMEOUT = 408;
522
523 /**
524 * Status code (409) indicating that the request could not be
525 * completed due to a conflict with the current state of the
526 * resource.
527 */
528
529 public static final int SC_CONFLICT = 409;
530
531 /**
532 * Status code (410) indicating that the resource is no longer
533 * available at the server and no forwarding address is known.
534 * This condition <em>SHOULD</em> be considered permanent.
535 */
536
537 public static final int SC_GONE = 410;
538
539 /**
540 * Status code (411) indicating that the request cannot be handled
541 * without a defined <code><em>Content-Length</em></code>.
542 */
543
544 public static final int SC_LENGTH_REQUIRED = 411;
545
546 /**
547 * Status code (412) indicating that the precondition given in one
548 * or more of the request-header fields evaluated to false when it
549 * was tested on the server.
550 */
551
552 public static final int SC_PRECONDITION_FAILED = 412;
553
554 /**
555 * Status code (413) indicating that the server is refusing to process
556 * the request because the request entity is larger than the server is
557 * willing or able to process.
558 */
559
560 public static final int SC_REQUEST_ENTITY_TOO_LARGE = 413;
561
562 /**
563 * Status code (414) indicating that the server is refusing to service
564 * the request because the <code><em>Request-URI</em></code> is longer
565 * than the server is willing to interpret.
566 */
567
568 public static final int SC_REQUEST_URI_TOO_LONG = 414;
569
570 /**
571 * Status code (415) indicating that the server is refusing to service
572 * the request because the entity of the request is in a format not
573 * supported by the requested resource for the requested method.
574 */
575
576 public static final int SC_UNSUPPORTED_MEDIA_TYPE = 415;
577
578 /**
579 * Status code (416) indicating that the server cannot serve the
580 * requested byte range.
581 */
582
583 public static final int SC_REQUESTED_RANGE_NOT_SATISFIABLE = 416;
584
585 /**
586 * Status code (417) indicating that the server could not meet the
587 * expectation given in the Expect request header.
588 */
589
590 public static final int SC_EXPECTATION_FAILED = 417;
591
592 /**
593 * Status code (500) indicating an error inside the HTTP server
594 * which prevented it from fulfilling the request.
595 */
596
597 public static final int SC_INTERNAL_SERVER_ERROR = 500;
598
599 /**
600 * Status code (501) indicating the HTTP server does not support
601 * the functionality needed to fulfill the request.
602 */
603
604 public static final int SC_NOT_IMPLEMENTED = 501;
605
606 /**
607 * Status code (502) indicating that the HTTP server received an
608 * invalid response from a server it consulted when acting as a
609 * proxy or gateway.
610 */
611
612 public static final int SC_BAD_GATEWAY = 502;
613
614 /**
615 * Status code (503) indicating that the HTTP server is
616 * temporarily overloaded, and unable to handle the request.
617 */
618
619 public static final int SC_SERVICE_UNAVAILABLE = 503;
620
621 /**
622 * Status code (504) indicating that the server did not receive
623 * a timely response from the upstream server while acting as
624 * a gateway or proxy.
625 */
626
627 public static final int SC_GATEWAY_TIMEOUT = 504;
628
629 /**
630 * Status code (505) indicating that the server does not support
631 * or refuses to support the HTTP protocol version that was used
632 * in the request message.
633 */
634
635 public static final int SC_HTTP_VERSION_NOT_SUPPORTED = 505;
636 }