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;
017
018 import java.io.BufferedReader;
019 import java.io.IOException;
020 import java.util.Enumeration;
021 import java.util.Locale;
022 import java.util.Map;
023
024 /**
025 * Defines an object to provide client request information to a servlet. The
026 * servlet container creates a <code>ServletRequest</code> object and passes
027 * it as an argument to the servlet's <code>service</code> method.
028 *
029 * <p>A <code>ServletRequest</code> object provides data including
030 * parameter name and values, attributes, and an input stream.
031 * Interfaces that extend <code>ServletRequest</code> can provide
032 * additional protocol-specific data (for example, HTTP data is
033 * provided by {@link javax.servlet.http.HttpServletRequest}.
034 *
035 * @author Various
036 * @version $Version$
037 *
038 * @see javax.servlet.http.HttpServletRequest
039 *
040 */
041
042 public interface ServletRequest {
043
044 /**
045 *
046 * Returns the value of the named attribute as an <code>Object</code>,
047 * or <code>null</code> if no attribute of the given name exists.
048 *
049 * <p> Attributes can be set two ways. The servlet container may set
050 * attributes to make available custom information about a request.
051 * For example, for requests made using HTTPS, the attribute
052 * <code>javax.servlet.request.X509Certificate</code> can be used to
053 * retrieve information on the certificate of the client. Attributes
054 * can also be set programatically using
055 * {@link ServletRequest#setAttribute}. This allows information to be
056 * embedded into a request before a {@link RequestDispatcher} call.
057 *
058 * <p>Attribute names should follow the same conventions as package
059 * names. This specification reserves names matching <code>java.*</code>,
060 * <code>javax.*</code>, and <code>sun.*</code>.
061 *
062 * @param name a <code>String</code> specifying the name of
063 * the attribute
064 *
065 * @return an <code>Object</code> containing the value
066 * of the attribute, or <code>null</code> if
067 * the attribute does not exist
068 *
069 */
070
071 public Object getAttribute(String name);
072
073 /**
074 * Returns an <code>Enumeration</code> containing the
075 * names of the attributes available to this request.
076 * This method returns an empty <code>Enumeration</code>
077 * if the request has no attributes available to it.
078 *
079 *
080 * @return an <code>Enumeration</code> of strings
081 * containing the names
082 * of the request's attributes
083 *
084 */
085
086 public Enumeration getAttributeNames();
087
088 /**
089 * Returns the name of the character encoding used in the body of this
090 * request. This method returns <code>null</code> if the request
091 * does not specify a character encoding
092 *
093 *
094 * @return a <code>String</code> containing the name of
095 * the character encoding, or <code>null</code>
096 * if the request does not specify a character encoding
097 *
098 */
099
100 public String getCharacterEncoding();
101
102 /**
103 * Overrides the name of the character encoding used in the body of this
104 * request. This method must be called prior to reading request parameters
105 * or reading input using getReader().
106 *
107 *
108 * @param env a <code>String</code> containing the name of
109 * the character encoding.
110 * @throws java.io.UnsupportedEncodingException if this is not a valid encoding
111 */
112
113 public void setCharacterEncoding(String env)
114 throws java.io.UnsupportedEncodingException;
115
116 /**
117 * Returns the length, in bytes, of the request body
118 * and made available by the input stream, or -1 if the
119 * length is not known. For HTTP servlets, same as the value
120 * of the CGI variable CONTENT_LENGTH.
121 *
122 * @return an integer containing the length of the
123 * request body or -1 if the length is not known
124 *
125 */
126
127 public int getContentLength();
128
129 /**
130 * Returns the MIME type of the body of the request, or
131 * <code>null</code> if the type is not known. For HTTP servlets,
132 * same as the value of the CGI variable CONTENT_TYPE.
133 *
134 * @return a <code>String</code> containing the name
135 * of the MIME type of
136 * the request, or null if the type is not known
137 *
138 */
139
140 public String getContentType();
141
142 /**
143 * Retrieves the body of the request as binary data using
144 * a {@link ServletInputStream}. Either this method or
145 * {@link #getReader} may be called to read the body, not both.
146 *
147 * @return a {@link ServletInputStream} object containing
148 * the body of the request
149 *
150 * @exception IllegalStateException if the {@link #getReader} method
151 * has already been called for this request
152 *
153 * @exception IOException if an input or output exception occurred
154 *
155 */
156
157 public ServletInputStream getInputStream() throws IOException;
158
159 /**
160 * Returns the value of a request parameter as a <code>String</code>,
161 * or <code>null</code> if the parameter does not exist. Request parameters
162 * are extra information sent with the request. For HTTP servlets,
163 * parameters are contained in the query string or posted form data.
164 *
165 * <p>You should only use this method when you are sure the
166 * parameter has only one value. If the parameter might have
167 * more than one value, use {@link #getParameterValues}.
168 *
169 * <p>If you use this method with a multivalued
170 * parameter, the value returned is equal to the first value
171 * in the array returned by <code>getParameterValues</code>.
172 *
173 * <p>If the parameter data was sent in the request body, such as occurs
174 * with an HTTP POST request, then reading the body directly via {@link
175 * #getInputStream} or {@link #getReader} can interfere
176 * with the execution of this method.
177 *
178 * @param name a <code>String</code> specifying the
179 * name of the parameter
180 *
181 * @return a <code>String</code> representing the
182 * single value of the parameter
183 *
184 * @see #getParameterValues
185 *
186 */
187
188 public String getParameter(String name);
189
190 /**
191 *
192 * Returns an <code>Enumeration</code> of <code>String</code>
193 * objects containing the names of the parameters contained
194 * in this request. If the request has
195 * no parameters, the method returns an
196 * empty <code>Enumeration</code>.
197 *
198 * @return an <code>Enumeration</code> of <code>String</code>
199 * objects, each <code>String</code> containing
200 * the name of a request parameter; or an
201 * empty <code>Enumeration</code> if the
202 * request has no parameters
203 *
204 */
205
206 public Enumeration getParameterNames();
207
208 /**
209 * Returns an array of <code>String</code> objects containing
210 * all of the values the given request parameter has, or
211 * <code>null</code> if the parameter does not exist.
212 *
213 * <p>If the parameter has a single value, the array has a length
214 * of 1.
215 *
216 * @param name a <code>String</code> containing the name of
217 * the parameter whose value is requested
218 *
219 * @return an array of <code>String</code> objects
220 * containing the parameter's values
221 *
222 * @see #getParameter
223 *
224 */
225
226 public String[] getParameterValues(String name);
227
228 /** Returns a java.util.Map of the parameters of this request.
229 * Request parameters
230 * are extra information sent with the request. For HTTP servlets,
231 * parameters are contained in the query string or posted form data.
232 *
233 * @return an immutable java.util.Map containing parameter names as
234 * keys and parameter values as map values. The keys in the parameter
235 * map are of type String. The values in the parameter map are of type
236 * String array.
237 *
238 */
239
240 public Map getParameterMap();
241
242 /**
243 * Returns the name and version of the protocol the request uses
244 * in the form <i>protocol/majorVersion.minorVersion</i>, for
245 * example, HTTP/1.1. For HTTP servlets, the value
246 * returned is the same as the value of the CGI variable
247 * <code>SERVER_PROTOCOL</code>.
248 *
249 * @return a <code>String</code> containing the protocol
250 * name and version number
251 *
252 */
253
254 public String getProtocol();
255
256 /**
257 * Returns the name of the scheme used to make this request,
258 * for example,
259 * <code>http</code>, <code>https</code>, or <code>ftp</code>.
260 * Different schemes have different rules for constructing URLs,
261 * as noted in RFC 1738.
262 *
263 * @return a <code>String</code> containing the name
264 * of the scheme used to make this request
265 *
266 */
267
268 public String getScheme();
269
270 /**
271 * Returns the host name of the server to which the request was sent.
272 * It is the value of the part before ":" in the <code>Host</code>
273 * header value, if any, or the resolved server name, or the server IP address.
274 *
275 * @return a <code>String</code> containing the name
276 * of the server
277 */
278
279 public String getServerName();
280
281 /**
282 * Returns the port number to which the request was sent.
283 * It is the value of the part after ":" in the <code>Host</code>
284 * header value, if any, or the server port where the client connection
285 * was accepted on.
286 *
287 * @return an integer specifying the port number
288 *
289 */
290
291 public int getServerPort();
292
293 /**
294 * Retrieves the body of the request as character data using
295 * a <code>BufferedReader</code>. The reader translates the character
296 * data according to the character encoding used on the body.
297 * Either this method or {@link #getInputStream} may be called to read the
298 * body, not both.
299 *
300 *
301 * @return a <code>BufferedReader</code>
302 * containing the body of the request
303 *
304 * @exception UnsupportedEncodingException if the character set encoding
305 * used is not supported and the
306 * text cannot be decoded
307 *
308 * @exception IllegalStateException if {@link #getInputStream} method
309 * has been called on this request
310 *
311 * @exception IOException if an input or output exception occurred
312 *
313 * @see #getInputStream
314 *
315 */
316
317 public BufferedReader getReader() throws IOException;
318
319 /**
320 * Returns the Internet Protocol (IP) address of the client
321 * or last proxy that sent the request.
322 * For HTTP servlets, same as the value of the
323 * CGI variable <code>REMOTE_ADDR</code>.
324 *
325 * @return a <code>String</code> containing the
326 * IP address of the client that sent the request
327 *
328 */
329
330 public String getRemoteAddr();
331
332 /**
333 * Returns the fully qualified name of the client
334 * or the last proxy that sent the request.
335 * If the engine cannot or chooses not to resolve the hostname
336 * (to improve performance), this method returns the dotted-string form of
337 * the IP address. For HTTP servlets, same as the value of the CGI variable
338 * <code>REMOTE_HOST</code>.
339 *
340 * @return a <code>String</code> containing the fully
341 * qualified name of the client
342 *
343 */
344
345 public String getRemoteHost();
346
347 /**
348 *
349 * Stores an attribute in this request.
350 * Attributes are reset between requests. This method is most
351 * often used in conjunction with {@link RequestDispatcher}.
352 *
353 * <p>Attribute names should follow the same conventions as
354 * package names. Names beginning with <code>java.*</code>,
355 * <code>javax.*</code>, and <code>com.sun.*</code>, are
356 * reserved for use by Sun Microsystems.
357 *<br> If the object passed in is null, the effect is the same as
358 * calling {@link #removeAttribute}.
359 * <br> It is warned that when the request is dispatched from the
360 * servlet resides in a different web application by
361 * <code>RequestDispatcher</code>, the object set by this method
362 * may not be correctly retrieved in the caller servlet.
363 *
364 *
365 * @param name a <code>String</code> specifying
366 * the name of the attribute
367 *
368 * @param o the <code>Object</code> to be stored
369 *
370 */
371
372 public void setAttribute(String name, Object o);
373
374 /**
375 *
376 * Removes an attribute from this request. This method is not
377 * generally needed as attributes only persist as long as the request
378 * is being handled.
379 *
380 * <p>Attribute names should follow the same conventions as
381 * package names. Names beginning with <code>java.*</code>,
382 * <code>javax.*</code>, and <code>com.sun.*</code>, are
383 * reserved for use by Sun Microsystems.
384 *
385 *
386 * @param name a <code>String</code> specifying
387 * the name of the attribute to remove
388 *
389 */
390
391 public void removeAttribute(String name);
392
393 /**
394 *
395 * Returns the preferred <code>Locale</code> that the client will
396 * accept content in, based on the Accept-Language header.
397 * If the client request doesn't provide an Accept-Language header,
398 * this method returns the default locale for the server.
399 *
400 *
401 * @return the preferred <code>Locale</code> for the client
402 *
403 */
404
405 public Locale getLocale();
406
407 /**
408 *
409 * Returns an <code>Enumeration</code> of <code>Locale</code> objects
410 * indicating, in decreasing order starting with the preferred locale, the
411 * locales that are acceptable to the client based on the Accept-Language
412 * header.
413 * If the client request doesn't provide an Accept-Language header,
414 * this method returns an <code>Enumeration</code> containing one
415 * <code>Locale</code>, the default locale for the server.
416 *
417 *
418 * @return an <code>Enumeration</code> of preferred
419 * <code>Locale</code> objects for the client
420 *
421 */
422
423 public Enumeration getLocales();
424
425 /**
426 *
427 * Returns a boolean indicating whether this request was made using a
428 * secure channel, such as HTTPS.
429 *
430 *
431 * @return a boolean indicating if the request was made using a
432 * secure channel
433 *
434 */
435
436 public boolean isSecure();
437
438 /**
439 *
440 * Returns a {@link RequestDispatcher} object that acts as a wrapper for
441 * the resource located at the given path.
442 * A <code>RequestDispatcher</code> object can be used to forward
443 * a request to the resource or to include the resource in a response.
444 * The resource can be dynamic or static.
445 *
446 * <p>The pathname specified may be relative, although it cannot extend
447 * outside the current servlet context. If the path begins with
448 * a "/" it is interpreted as relative to the current context root.
449 * This method returns <code>null</code> if the servlet container
450 * cannot return a <code>RequestDispatcher</code>.
451 *
452 * <p>The difference between this method and {@link
453 * ServletContext#getRequestDispatcher} is that this method can take a
454 * relative path.
455 *
456 * @param path a <code>String</code> specifying the pathname
457 * to the resource. If it is relative, it must be
458 * relative against the current servlet.
459 *
460 * @return a <code>RequestDispatcher</code> object
461 * that acts as a wrapper for the resource
462 * at the specified path, or <code>null</code>
463 * if the servlet container cannot return a
464 * <code>RequestDispatcher</code>
465 *
466 * @see RequestDispatcher
467 * @see ServletContext#getRequestDispatcher
468 *
469 */
470
471 public RequestDispatcher getRequestDispatcher(String path);
472
473 /**
474 *
475 * @deprecated As of Version 2.1 of the Java Servlet API,
476 * use {@link ServletContext#getRealPath} instead.
477 *
478 */
479
480 public String getRealPath(String path);
481
482 /**
483 * Returns the Internet Protocol (IP) source port of the client
484 * or last proxy that sent the request.
485 *
486 * @return an integer specifying the port number
487 *
488 * @since 2.4
489 */
490 public int getRemotePort();
491
492 /**
493 * Returns the host name of the Internet Protocol (IP) interface on
494 * which the request was received.
495 *
496 * @return a <code>String</code> containing the host
497 * name of the IP on which the request was received.
498 *
499 * @since 2.4
500 */
501 public String getLocalName();
502
503 /**
504 * Returns the Internet Protocol (IP) address of the interface on
505 * which the request was received.
506 *
507 * @return a <code>String</code> containing the
508 * IP address on which the request was received.
509 *
510 * @since 2.4
511 *
512 */
513 public String getLocalAddr();
514
515 /**
516 * Returns the Internet Protocol (IP) port number of the interface
517 * on which the request was received.
518 *
519 * @return an integer specifying the port number
520 *
521 * @since 2.4
522 */
523 public int getLocalPort();
524
525 }
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