001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements. See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership. The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License. You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied. See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019
020 //
021 // This source code implements specifications defined by the Java
022 // Community Process. In order to remain compliant with the specification
023 // DO NOT add / change / or delete method signatures!
024 //
025
026 package javax.servlet;
027
028 import java.io.BufferedReader;
029 import java.io.IOException;
030 import java.util.Enumeration;
031 import java.util.Locale;
032 import java.util.Map;
033
034
035 /**
036 * Defines an object to provide client request information to a servlet. The
037 * servlet container creates a <code>ServletRequest</code> object and passes
038 * it as an argument to the servlet's <code>service</code> method.
039 *
040 * <p>A <code>ServletRequest</code> object provides data including
041 * parameter name and values, attributes, and an input stream.
042 * Interfaces that extend <code>ServletRequest</code> can provide
043 * additional protocol-specific data (for example, HTTP data is
044 * provided by {@link javax.servlet.http.HttpServletRequest}.
045 *
046 * @see javax.servlet.http.HttpServletRequest
047 *
048 * @version $Rev: 467553 $ $Date: 2006-10-24 21:01:51 -0700 (Tue, 24 Oct 2006) $
049 */
050 public interface ServletRequest {
051 /**
052 * Returns the value of the named attribute as an <code>Object</code>,
053 * or <code>null</code> if no attribute of the given name exists.
054 *
055 * <p> Attributes can be set two ways. The servlet container may set
056 * attributes to make available custom information about a request.
057 * For example, for requests made using HTTPS, the attribute
058 * <code>javax.servlet.request.X509Certificate</code> can be used to
059 * retrieve information on the certificate of the client. Attributes
060 * can also be set programatically using
061 * {@link ServletRequest#setAttribute}. This allows information to be
062 * embedded into a request before a {@link RequestDispatcher} call.
063 *
064 * <p>Attribute names should follow the same conventions as package
065 * names. This specification reserves names matching <code>java.*</code>,
066 * <code>javax.*</code>, and <code>sun.*</code>.
067 *
068 * @param name a <code>String</code> specifying the name of
069 * the attribute
070 *
071 * @return an <code>Object</code> containing the value
072 * of the attribute, or <code>null</code> if the attribute does not exist
073 */
074 public Object getAttribute(String name);
075
076 /**
077 * Returns an <code>Enumeration</code> containing the
078 * names of the attributes available to this request.
079 * This method returns an empty <code>Enumeration</code>
080 * if the request has no attributes available to it.
081 *
082 *
083 * @return an <code>Enumeration</code> of strings
084 * containing the names of the request's attributes
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 * @return a <code>String</code> containing the name of
094 * the chararacter encoding, or <code>null</code>
095 * if the request does not specify a character encoding
096 */
097 public String getCharacterEncoding();
098
099 /**
100 * Overrides the name of the character encoding used in the body of this
101 * request. This method must be called prior to reading request parameters
102 * or reading input using getReader().
103 *
104 * @param env a <code>String</code> containing the name of
105 * the chararacter encoding.
106 *
107 * @throws java.io.UnsupportedEncodingException if this is not a valid encoding
108 */
109 public void setCharacterEncoding(String env) throws java.io.UnsupportedEncodingException;
110
111 /**
112 * Returns the length, in bytes, of the request body
113 * and made available by the input stream, or -1 if the
114 * length is not known. For HTTP servlets, same as the value
115 * of the CGI variable CONTENT_LENGTH.
116 *
117 * @return an integer containing the length of the
118 * request body or -1 if the length is not known
119 */
120 public int getContentLength();
121
122 /**
123 * Returns the MIME type of the body of the request, or
124 * <code>null</code> if the type is not known. For HTTP servlets,
125 * same as the value of the CGI variable CONTENT_TYPE.
126 *
127 * @return a <code>String</code> containing the name
128 * of the MIME type of the request, or null if the type is not known
129 */
130 public String getContentType();
131
132 /**
133 * Retrieves the body of the request as binary data using
134 * a {@link ServletInputStream}. Either this method or
135 * {@link #getReader} may be called to read the body, not both.
136 *
137 * @return a {@link ServletInputStream} object containing
138 * the body of the request
139 *
140 * @exception IllegalStateException if the {@link #getReader} method
141 * has already been called for this request
142 *
143 * @exception IOException if an input or output exception occurred
144 */
145 public ServletInputStream getInputStream() throws IOException;
146
147 /**
148 * Returns the value of a request parameter as a <code>String</code>,
149 * or <code>null</code> if the parameter does not exist. Request parameters
150 * are extra information sent with the request. For HTTP servlets,
151 * parameters are contained in the query string or posted form data.
152 *
153 * <p>You should only use this method when you are sure the
154 * parameter has only one value. If the parameter might have
155 * more than one value, use {@link #getParameterValues}.
156 *
157 * <p>If you use this method with a multivalued
158 * parameter, the value returned is equal to the first value
159 * in the array returned by <code>getParameterValues</code>.
160 *
161 * <p>If the parameter data was sent in the request body, such as occurs
162 * with an HTTP POST request, then reading the body directly via {@link
163 * #getInputStream} or {@link #getReader} can interfere
164 * with the execution of this method.
165 *
166 * @param name a <code>String</code> specifying the
167 * name of the parameter
168 *
169 * @return a <code>String</code> representing the
170 * single value of the parameter
171 *
172 * @see #getParameterValues
173 */
174 public String getParameter(String name);
175
176 /**
177 * Returns an <code>Enumeration</code> of <code>String</code>
178 * objects containing the names of the parameters contained
179 * in this request. If the request has
180 * no parameters, the method returns an
181 * empty <code>Enumeration</code>.
182 *
183 * @return an <code>Enumeration</code> of <code>String</code>
184 * objects, each <code>String</code> containing
185 * the name of a request parameter; or an
186 * empty <code>Enumeration</code> if the
187 * request has no parameters
188 */
189 public Enumeration getParameterNames();
190
191 /**
192 * Returns an array of <code>String</code> objects containing
193 * all of the values the given request parameter has, or
194 * <code>null</code> if the parameter does not exist.
195 *
196 * <p>If the parameter has a single value, the array has a length
197 * of 1.
198 *
199 * @param name a <code>String</code> containing the name of
200 * the parameter whose value is requested
201 *
202 * @return an array of <code>String</code> objects
203 * containing the parameter's values
204 *
205 * @see #getParameter
206 */
207 public String[] getParameterValues(String name);
208
209 /**
210 * Returns a java.util.Map of the parameters of this request.
211 * Request parameters are extra information sent with the request.
212 * For HTTP servlets, parameters are contained in the query
213 * string or posted form data.
214 *
215 * @return an immutable java.util.Map containing parameter names as
216 * keys and parameter values as map values. The keys in the parameter
217 * map are of type String. The values in the parameter map are of type
218 * String array.
219 */
220 public Map getParameterMap();
221
222 /**
223 * Returns the name and version of the protocol the request uses
224 * in the form <i>protocol/majorVersion.minorVersion</i>, for
225 * example, HTTP/1.1. For HTTP servlets, the value
226 * returned is the same as the value of the CGI variable
227 * <code>SERVER_PROTOCOL</code>.
228 *
229 * @return a <code>String</code> containing the protocol
230 * name and version number
231 */
232 public String getProtocol();
233
234 /**
235 * Returns the name of the scheme used to make this request,
236 * for example,
237 * <code>http</code>, <code>https</code>, or <code>ftp</code>.
238 * Different schemes have different rules for constructing URLs,
239 * as noted in RFC 1738.
240 *
241 * @return a <code>String</code> containing the name
242 * of the scheme used to make this request
243 */
244 public String getScheme();
245
246 /**
247 * Returns the host name of the server to which the request was sent.
248 * It is the value of the part before ":" in the <code>Host</code>
249 * header, if any, or the resolved server name, or the server IP address.
250 *
251 * @return a <code>String</code> containing the name
252 * of the server
253 */
254 public String getServerName();
255
256 /**
257 * Returns the port number to which the request was sent.
258 * It is the value of the part after ":" in the <code>Host</code>
259 * header, if any, or the server port where the client connection
260 * was accepted on.
261 *
262 * @return an integer specifying the port number
263 */
264 public int getServerPort();
265
266 /**
267 * Retrieves the body of the request as character data using
268 * a <code>BufferedReader</code>. The reader translates the character
269 * data according to the character encoding used on the body.
270 * Either this method or {@link #getInputStream} may be called to read the
271 * body, not both.
272 *
273 * @return a <code>BufferedReader</code> containing the body of the request
274 *
275 * @exception UnsupportedEncodingException if the character set encoding
276 * used is not supported and the text cannot be decoded
277 *
278 * @exception IllegalStateException if {@link #getInputStream} method
279 * has been called on this request
280 *
281 * @exception IOException if an input or output exception occurred
282 *
283 * @see #getInputStream
284 */
285 public BufferedReader getReader() throws IOException;
286
287 /**
288 * Returns the Internet Protocol (IP) address of the client
289 * or last proxy that sent the request.
290 * For HTTP servlets, same as the value of the
291 * CGI variable <code>REMOTE_ADDR</code>.
292 *
293 * @return a <code>String</code> containing the
294 * IP address of the client that sent the request
295 */
296 public String getRemoteAddr();
297
298 /**
299 * Returns the fully qualified name of the client
300 * or the last proxy that sent the request.
301 * If the engine cannot or chooses not to resolve the hostname
302 * (to improve performance), this method returns the dotted-string form of
303 * the IP address. For HTTP servlets, same as the value of the CGI variable
304 * <code>REMOTE_HOST</code>.
305 *
306 * @return a <code>String</code> containing the fully
307 * qualified name of the client
308 */
309 public String getRemoteHost();
310
311 /**
312 * Stores an attribute in this request.
313 * Attributes are reset between requests. This method is most
314 * often used in conjunction with {@link RequestDispatcher}.
315 *
316 * <p>Attribute names should follow the same conventions as
317 * package names. Names beginning with <code>java.*</code>,
318 * <code>javax.*</code>, and <code>com.sun.*</code>, are
319 * reserved for use by Sun Microsystems.
320 *<br> If the object passed in is null, the effect is the same as
321 * calling {@link #removeAttribute}.
322 *
323 * @param name a <code>String</code> specifying the name of the attribute
324 *
325 * @param o the <code>Object</code> to be stored
326 */
327 public void setAttribute(String name, Object o);
328
329 /**
330 * Removes an attribute from this request. This method is not
331 * generally needed as attributes only persist as long as the request
332 * is being handled.
333 *
334 * <p>Attribute names should follow the same conventions as
335 * package names. Names beginning with <code>java.*</code>,
336 * <code>javax.*</code>, and <code>com.sun.*</code>, are
337 * reserved for use by Sun Microsystems.
338 *
339 * @param name a <code>String</code> specifying
340 * the name of the attribute to remove
341 */
342 public void removeAttribute(String name);
343
344 /**
345 * Returns the preferred <code>Locale</code> that the client will
346 * accept content in, based on the Accept-Language header.
347 * If the client request doesn't provide an Accept-Language header,
348 * this method returns the default locale for the server.
349 *
350 * @return the preferred <code>Locale</code> for the client
351 */
352 public Locale getLocale();
353
354 /**
355 * Returns an <code>Enumeration</code> of <code>Locale</code> objects
356 * indicating, in decreasing order starting with the preferred locale, the
357 * locales that are acceptable to the client based on the Accept-Language
358 * header.
359 * If the client request doesn't provide an Accept-Language header,
360 * this method returns an <code>Enumeration</code> containing one
361 * <code>Locale</code>, the default locale for the server.
362 *
363 * @return an <code>Enumeration</code> of preferred
364 * <code>Locale</code> objects for the client
365 */
366 public Enumeration getLocales();
367
368 /**
369 * Returns a boolean indicating whether this request was made using a
370 * secure channel, such as HTTPS.
371 *
372 * @return a boolean indicating if the request was made using a
373 * secure channel
374 */
375 public boolean isSecure();
376
377 /**
378 * Returns a {@link RequestDispatcher} object that acts as a wrapper for
379 * the resource located at the given path.
380 * A <code>RequestDispatcher</code> object can be used to forward
381 * a request to the resource or to include the resource in a response.
382 * The resource can be dynamic or static.
383 *
384 * <p>The pathname specified may be relative, although it cannot extend
385 * outside the current servlet context. If the path begins with
386 * a "/" it is interpreted as relative to the current context root.
387 * This method returns <code>null</code> if the servlet container
388 * cannot return a <code>RequestDispatcher</code>.
389 *
390 * <p>The difference between this method and {@link
391 * ServletContext#getRequestDispatcher} is that this method can take a
392 * relative path.
393 *
394 * @param path a <code>String</code> specifying the pathname to the
395 * resource. If it is relative, it must be relative against the
396 * current servlet.
397 *
398 * @return a <code>RequestDispatcher</code> object that acts as a
399 * wrapper for the resource at the specified path, or <code>null</code>
400 * if the servlet container cannot return a
401 * <code>RequestDispatcher</code>
402 *
403 * @see RequestDispatcher
404 * @see ServletContext#getRequestDispatcher
405 */
406 public RequestDispatcher getRequestDispatcher(String path);
407
408 /**
409 * @deprecated As of Version 2.1 of the Java Servlet API,
410 * use {@link ServletContext#getRealPath} instead.
411 */
412 public String getRealPath(String path);
413
414 /**
415 * Returns the Internet Protocol (IP) source port of the client
416 * or last proxy that sent the request.
417 *
418 * @since Servlet 2.4
419 */
420 public int getRemotePort();
421
422 /**
423 * Returns the host name of the Internet Protocol (IP) interface on
424 * which the request was received.
425 *
426 * @return a <code>String</code> containing the host
427 * name of the IP on which the request was received.
428 *
429 * @since Servlet 2.4
430 */
431 public String getLocalName();
432
433 /**
434 * Returns the Internet Protocol (IP) address of the interface on
435 * which the request was received.
436 *
437 * @return a <code>String</code> containing the
438 * IP address on which the request was received.
439 *
440 * @since Servlet 2.4
441 */
442 public String getLocalAddr();
443
444 /**
445 * Returns the Internet Protocol (IP) port number of the interface
446 * on which the request was received.
447 *
448 * @return an integer specifying the port number
449 *
450 * @since Servlet 2.4
451 */
452 public int getLocalPort();
453 }
454