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1   /**
2    *
3    * Copyright 2003-2004 The Apache Software Foundation
4    *
5    *  Licensed under the Apache License, Version 2.0 (the "License");
6    *  you may not use this file except in compliance with the License.
7    *  You may obtain a copy of the License at
8    *
9    *     http://www.apache.org/licenses/LICENSE-2.0
10   *
11   *  Unless required by applicable law or agreed to in writing, software
12   *  distributed under the License is distributed on an "AS IS" BASIS,
13   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   *  See the License for the specific language governing permissions and
15   *  limitations under the License.
16   */
17  
18  //
19  // This source code implements specifications defined by the Java
20  // Community Process. In order to remain compliant with the specification
21  // DO NOT add / change / or delete method signatures!
22  //
23  
24  package javax.servlet.http;
25  
26  import java.io.IOException;
27  import javax.servlet.ServletResponse;
28  
29  /**
30   * Extends the {@link ServletResponse} interface to provide HTTP-specific
31   * functionality in sending a response.  For example, it has methods
32   * to access HTTP headers and cookies.
33   *
34   * <p>The servlet container creates an <code>HttpServletResponse</code> object
35   * and passes it as an argument to the servlet's service methods
36   * (<code>doGet</code>, <code>doPost</code>, etc).
37   *
38   * @see javax.servlet.ServletResponse
39   *
40   * @version $Rev: 46019 $ $Date: 2004-09-14 02:56:06 -0700 (Tue, 14 Sep 2004) $
41   */
42  public interface HttpServletResponse extends ServletResponse {
43      /**
44       * Adds the specified cookie to the response.  This method can be called
45       * multiple times to set more than one cookie.
46       *
47       * @param cookie the Cookie to return to the client
48       */
49      public void addCookie(Cookie cookie);
50  
51      /**
52       * Returns a boolean indicating whether the named response header has
53       * already been set.
54       *
55       * @param name the header name
56       * @return <code>true</code> if the named response header has already been
57       * set; <code>false</code> otherwise
58       */
59      public boolean containsHeader(String name);
60  
61      /**
62       * Encodes the specified URL by including the session ID in it,
63       * or, if encoding is not needed, returns the URL unchanged.
64       * The implementation of this method includes the logic to
65       * determine whether the session ID needs to be encoded in the URL.
66       * For example, if the browser supports cookies, or session
67       * tracking is turned off, URL encoding is unnecessary.
68       *
69       * <p>For robust session tracking, all URLs emitted by a servlet
70       * should be run through this
71       * method.  Otherwise, URL rewriting cannot be used with browsers
72       * which do not support cookies.
73       *
74       * @param url the url to be encoded.
75       * @return the encoded URL if encoding is needed; the unchanged URL
76       * otherwise.
77       */
78      public String encodeURL(String url);
79  
80      /**
81       * Encodes the specified URL for use in the
82       * <code>sendRedirect</code> method or, if encoding is not needed,
83       * returns the URL unchanged.  The implementation of this method
84       * includes the logic to determine whether the session ID
85       * needs to be encoded in the URL.  Because the rules for making
86       * this determination can differ from those used to decide whether to
87       * encode a normal link, this method is separete from the
88       * <code>encodeURL</code> method.
89       *
90       * <p>All URLs sent to the <code>HttpServletResponse.sendRedirect</code>
91       * method should be run through this method.  Otherwise, URL
92       * rewriting cannot be used with browsers which do not support
93       * cookies.
94       *
95       * @param url the url to be encoded.
96       * @return the encoded URL if encoding is needed; the unchanged URL
97       * otherwise.
98       *
99       * @see #sendRedirect
100      * @see #encodeUrl
101      */
102     public String encodeRedirectURL(String url);
103 
104     /**
105      * @deprecated As of version 2.1, use encodeURL(String url) instead
106      *
107      * @param url the url to be encoded.
108      * @return the encoded URL if encoding is needed; the unchanged URL
109      * otherwise.
110      */
111     public String encodeUrl(String url);
112 
113     /**
114      * @deprecated As of version 2.1, use encodeRedirectURL(String url) instead
115      *
116      * @param url the url to be encoded.
117      * @return the encoded URL if encoding is needed; the unchanged URL
118      * otherwise.
119      */
120     public String encodeRedirectUrl(String url);
121 
122     /**
123      * Sends an error response to the client using the specified
124      * status.  The server defaults to creating the
125      * response to look like an HTML-formatted server error page
126      * containing the specified message, setting the content type
127      * to "text/html", leaving cookies and other headers unmodified.
128      *
129      * If an error-page declaration has been made for the web application
130      * corresponding to the status code passed in, it will be served back in
131      * preference to the suggested msg parameter.
132      *
133      * <p>If the response has already been committed, this method throws
134      * an IllegalStateException.
135      * After using this method, the response should be considered
136      * to be committed and should not be written to.
137      *
138      * @param sc the error status code
139      * @param msg the descriptive message
140      * @exception IOException If an input or output exception occurs
141      * @exception IllegalStateException If the response was committed
142      */
143     public void sendError(int sc, String msg) throws IOException;
144 
145     /**
146      * Sends an error response to the client using the specified status
147      * code and clearing the buffer.
148      * <p>If the response has already been committed, this method throws
149      * an IllegalStateException.
150      * After using this method, the response should be considered
151      * to be committed and should not be written to.
152      *
153      * @param sc the error status code
154      * @exception IOException If an input or output exception occurs
155      * @exception IllegalStateException If the response was committed
156      * before this method call
157      */
158     public void sendError(int sc) throws IOException;
159 
160     /**
161      * Sends a temporary redirect response to the client using the
162      * specified redirect location URL.  This method can accept relative URLs;
163      * the servlet container must convert the relative URL to an absolute URL
164      * before sending the response to the client. If the location is relative
165      * without a leading '/' the container interprets it as relative to
166      * the current request URI. If the location is relative with a leading
167      * '/' the container interprets it as relative to the servlet container root.
168      *
169      * <p>If the response has already been committed, this method throws
170      * an IllegalStateException.
171      * After using this method, the response should be considered
172      * to be committed and should not be written to.
173      *
174      * @param location the redirect location URL
175      * @exception IOException If an input or output exception occurs
176      * @exception IllegalStateException If the response was committed or
177      * if a partial URL is given and cannot be converted into a valid URL
178      */
179     public void sendRedirect(String location) throws IOException;
180 
181     /**
182      * Sets a response header with the given name and
183      * date-value.  The date is specified in terms of
184      * milliseconds since the epoch.  If the header had already
185      * been set, the new value overwrites the previous one.  The
186      * <code>containsHeader</code> method can be used to test for the
187      * presence of a header before setting its value.
188      *
189      * @param name the name of the header to set
190      * @param date the assigned date value
191      *
192      * @see #containsHeader
193      * @see #addDateHeader
194      */
195     public void setDateHeader(String name, long date);
196 
197     /**
198      * Adds a response header with the given name and
199      * date-value.  The date is specified in terms of
200      * milliseconds since the epoch.  This method allows response headers
201      * to have multiple values.
202      *
203      * @param name the name of the header to set
204      * @param date the additional date value
205      *
206      * @see #setDateHeader
207      */
208     public void addDateHeader(String name, long date);
209 
210     /**
211      * Sets a response header with the given name and value.
212      * If the header had already been set, the new value overwrites the
213      * previous one.  The <code>containsHeader</code> method can be
214      * used to test for the presence of a header before setting its
215      * value.
216      *
217      * @param name the name of the header
218      * @param value the header value  If it contains octet string,
219      * it should be encoded according to RFC 2047
220      * (http://www.ietf.org/rfc/rfc2047.txt)
221      *
222      * @see #containsHeader
223      * @see #addHeader
224      */
225     public void setHeader(String name, String value);
226 
227     /**
228      * Adds a response header with the given name and value.
229      * This method allows response headers to have multiple values.
230      *
231      * @param name the name of the header
232      * @param value the additional header value If it contains octet string,
233      * it should be encoded according to RFC 2047
234      * (http://www.ietf.org/rfc/rfc2047.txt)
235      *
236      * @see #setHeader
237      */
238     public void addHeader(String name, String value);
239 
240     /**
241      * Sets a response header with the given name and
242      * integer value.  If the header had already been set, the new value
243      * overwrites the previous one.  The <code>containsHeader</code>
244      * method can be used to test for the presence of a header before
245      * setting its value.
246      *
247      * @param name the name of the header
248      * @param value the assigned integer value
249      *
250      * @see #containsHeader
251      * @see #addIntHeader
252      */
253     public void setIntHeader(String name, int value);
254 
255     /**
256      * Adds a response header with the given name and
257      * integer value.  This method allows response headers to have multiple
258      * values.
259      *
260      * @param name the name of the header
261      * @param value the assigned integer value
262      *
263      * @see #setIntHeader
264      */
265     public void addIntHeader(String name, int value);
266 
267     /**
268      * Sets the status code for this response.  This method is used to
269      * set the return status code when there is no error (for example,
270      * for the status codes SC_OK or SC_MOVED_TEMPORARILY).  If there
271      * is an error, and the caller wishes to invoke an error-page defined
272      * in the web applicaion, the <code>sendError</code> method should be used
273      * instead.
274      * <p> The container clears the buffer and sets the Location header, preserving
275      * cookies and other headers.
276      *
277      * @param sc the status code
278      *
279      * @see #sendError
280      */
281     public void setStatus(int sc);
282 
283     /**
284      * @deprecated As of version 2.1, due to ambiguous meaning of the
285      * message parameter. To set a status code
286      * use <code>setStatus(int)</code>, to send an error with a description
287      * use <code>sendError(int, String)</code>.
288      *
289      * Sets the status code and message for this response.
290      *
291      * @param sc the status code
292      * @param sm the status message
293      */
294     public void setStatus(int sc, String sm);
295 
296     //
297     // Server status codes; see RFC 2068.
298     //
299 
300     /**
301      * Status code (100) indicating the client can continue.
302      */
303     public static final int SC_CONTINUE = 100;
304 
305     /**
306      * Status code (101) indicating the server is switching protocols
307      * according to Upgrade header.
308      */
309     public static final int SC_SWITCHING_PROTOCOLS = 101;
310 
311     /**
312      * Status code (200) indicating the request succeeded normally.
313      */
314     public static final int SC_OK = 200;
315 
316     /**
317      * Status code (201) indicating the request succeeded and created
318      * a new resource on the server.
319      */
320     public static final int SC_CREATED = 201;
321 
322     /**
323      * Status code (202) indicating that a request was accepted for
324      * processing, but was not completed.
325      */
326     public static final int SC_ACCEPTED = 202;
327 
328     /**
329      * Status code (203) indicating that the meta information presented
330      * by the client did not originate from the server.
331      */
332     public static final int SC_NON_AUTHORITATIVE_INFORMATION = 203;
333 
334     /**
335      * Status code (204) indicating that the request succeeded but that
336      * there was no new information to return.
337      */
338     public static final int SC_NO_CONTENT = 204;
339 
340     /**
341      * Status code (205) indicating that the agent <em>SHOULD</em> reset
342      * the document view which caused the request to be sent.
343      */
344     public static final int SC_RESET_CONTENT = 205;
345 
346     /**
347      * Status code (206) indicating that the server has fulfilled
348      * the partial GET request for the resource.
349      */
350     public static final int SC_PARTIAL_CONTENT = 206;
351 
352     /**
353      * Status code (300) indicating that the requested resource
354      * corresponds to any one of a set of representations, each with
355      * its own specific location.
356      */
357     public static final int SC_MULTIPLE_CHOICES = 300;
358 
359     /**
360      * Status code (301) indicating that the resource has permanently
361      * moved to a new location, and that future references should use a
362      * new URI with their requests.
363      */
364     public static final int SC_MOVED_PERMANENTLY = 301;
365 
366     /**
367      * Status code (302) indicating that the resource has temporarily
368      * moved to another location, but that future references should
369      * still use the original URI to access the resource.
370      *
371      * This definition is being retained for backwards compatibility.
372      * SC_FOUND is now the preferred definition.
373      */
374     public static final int SC_MOVED_TEMPORARILY = 302;
375 
376     /**
377      * Status code (302) indicating that the resource reside
378      * temporarily under a different URI. Since the redirection might
379      * be altered on occasion, the client should continue to use the
380      * Request-URI for future requests.(HTTP/1.1) To represent the
381      * status code (302), it is recommended to use this variable.
382      */
383     public static final int SC_FOUND = 302;
384 
385     /**
386      * Status code (303) indicating that the response to the request
387      * can be found under a different URI.
388      */
389     public static final int SC_SEE_OTHER = 303;
390 
391     /**
392      * Status code (304) indicating that a conditional GET operation
393      * found that the resource was available and not modified.
394      */
395     public static final int SC_NOT_MODIFIED = 304;
396 
397     /**
398      * Status code (305) indicating that the requested resource
399      * <em>MUST</em> be accessed through the proxy given by the
400      * <code><em>Location</em></code> field.
401      */
402     public static final int SC_USE_PROXY = 305;
403 
404     /**
405      * Status code (307) indicating that the requested resource
406      * resides temporarily under a different URI. The temporary URI
407      * <em>SHOULD</em> be given by the <code><em>Location</em></code>
408      * field in the response.
409      */
410     public static final int SC_TEMPORARY_REDIRECT = 307;
411 
412     /**
413      * Status code (400) indicating the request sent by the client was
414      * syntactically incorrect.
415      */
416     public static final int SC_BAD_REQUEST = 400;
417 
418     /**
419      * Status code (401) indicating that the request requires HTTP
420      * authentication.
421      */
422     public static final int SC_UNAUTHORIZED = 401;
423 
424     /**
425      * Status code (402) reserved for future use.
426      */
427     public static final int SC_PAYMENT_REQUIRED = 402;
428 
429     /**
430      * Status code (403) indicating the server understood the request
431      * but refused to fulfill it.
432      */
433     public static final int SC_FORBIDDEN = 403;
434 
435     /**
436      * Status code (404) indicating that the requested resource is not
437      * available.
438      */
439     public static final int SC_NOT_FOUND = 404;
440 
441     /**
442      * Status code (405) indicating that the method specified in the
443      * <code><em>Request-Line</em></code> is not allowed for the resource
444      * identified by the <code><em>Request-URI</em></code>.
445      */
446     public static final int SC_METHOD_NOT_ALLOWED = 405;
447 
448     /**
449      * Status code (406) indicating that the resource identified by the
450      * request is only capable of generating response entities which have
451      * content characteristics not acceptable according to the accept
452      * headers sent in the request.
453      */
454     public static final int SC_NOT_ACCEPTABLE = 406;
455 
456     /**
457      * Status code (407) indicating that the client <em>MUST</em> first
458      * authenticate itself with the proxy.
459      */
460     public static final int SC_PROXY_AUTHENTICATION_REQUIRED = 407;
461 
462     /**
463      * Status code (408) indicating that the client did not produce a
464      * request within the time that the server was prepared to wait.
465      */
466     public static final int SC_REQUEST_TIMEOUT = 408;
467 
468     /**
469      * Status code (409) indicating that the request could not be
470      * completed due to a conflict with the current state of the
471      * resource.
472      */
473     public static final int SC_CONFLICT = 409;
474 
475     /**
476      * Status code (410) indicating that the resource is no longer
477      * available at the server and no forwarding address is known.
478      * This condition <em>SHOULD</em> be considered permanent.
479      */
480     public static final int SC_GONE = 410;
481 
482     /**
483      * Status code (411) indicating that the request cannot be handled
484      * without a defined <code><em>Content-Length</em></code>.
485      */
486     public static final int SC_LENGTH_REQUIRED = 411;
487 
488     /**
489      * Status code (412) indicating that the precondition given in one
490      * or more of the request-header fields evaluated to false when it
491      * was tested on the server.
492      */
493     public static final int SC_PRECONDITION_FAILED = 412;
494 
495     /**
496      * Status code (413) indicating that the server is refusing to process
497      * the request because the request entity is larger than the server is
498      * willing or able to process.
499      */
500     public static final int SC_REQUEST_ENTITY_TOO_LARGE = 413;
501 
502     /**
503      * Status code (414) indicating that the server is refusing to service
504      * the request because the <code><em>Request-URI</em></code> is longer
505      * than the server is willing to interpret.
506      */
507     public static final int SC_REQUEST_URI_TOO_LONG = 414;
508 
509     /**
510      * Status code (415) indicating that the server is refusing to service
511      * the request because the entity of the request is in a format not
512      * supported by the requested resource for the requested method.
513      */
514     public static final int SC_UNSUPPORTED_MEDIA_TYPE = 415;
515 
516     /**
517      * Status code (416) indicating that the server cannot serve the
518      * requested byte range.
519      */
520     public static final int SC_REQUESTED_RANGE_NOT_SATISFIABLE = 416;
521 
522     /**
523      * Status code (417) indicating that the server could not meet the
524      * expectation given in the Expect request header.
525      */
526     public static final int SC_EXPECTATION_FAILED = 417;
527 
528     /**
529      * Status code (500) indicating an error inside the HTTP server
530      * which prevented it from fulfilling the request.
531      */
532     public static final int SC_INTERNAL_SERVER_ERROR = 500;
533 
534     /**
535      * Status code (501) indicating the HTTP server does not support
536      * the functionality needed to fulfill the request.
537      */
538     public static final int SC_NOT_IMPLEMENTED = 501;
539 
540     /**
541      * Status code (502) indicating that the HTTP server received an
542      * invalid response from a server it consulted when acting as a
543      * proxy or gateway.
544      */
545     public static final int SC_BAD_GATEWAY = 502;
546 
547     /**
548      * Status code (503) indicating that the HTTP server is
549      * temporarily overloaded, and unable to handle the request.
550      */
551     public static final int SC_SERVICE_UNAVAILABLE = 503;
552 
553     /**
554      * Status code (504) indicating that the server did not receive
555      * a timely response from the upstream server while acting as
556      * a gateway or proxy.
557      */
558     public static final int SC_GATEWAY_TIMEOUT = 504;
559 
560     /**
561      * Status code (505) indicating that the server does not support
562      * or refuses to support the HTTP protocol version that was used
563      * in the request message.
564      */
565     public static final int SC_HTTP_VERSION_NOT_SUPPORTED = 505;
566 }