001 /**
002 *
003 * Copyright 2003-2004 The Apache Software Foundation
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018 //
019 // This source code implements specifications defined by the Java
020 // Community Process. In order to remain compliant with the specification
021 // DO NOT add / change / or delete method signatures!
022 //
023
024 package javax.servlet;
025
026 import java.io.BufferedReader;
027 import java.io.IOException;
028 import java.util.Enumeration;
029 import java.util.Locale;
030 import java.util.Map;
031
032
033 /**
034 * Defines an object to provide client request information to a servlet. The
035 * servlet container creates a <code>ServletRequest</code> object and passes
036 * it as an argument to the servlet's <code>service</code> method.
037 *
038 * <p>A <code>ServletRequest</code> object provides data including
039 * parameter name and values, attributes, and an input stream.
040 * Interfaces that extend <code>ServletRequest</code> can provide
041 * additional protocol-specific data (for example, HTTP data is
042 * provided by {@link javax.servlet.http.HttpServletRequest}.
043 *
044 * @see javax.servlet.http.HttpServletRequest
045 *
046 * @version $Rev: 46019 $ $Date: 2004-09-14 02:56:06 -0700 (Tue, 14 Sep 2004) $
047 */
048 public interface ServletRequest {
049 /**
050 * Returns the value of the named attribute as an <code>Object</code>,
051 * or <code>null</code> if no attribute of the given name exists.
052 *
053 * <p> Attributes can be set two ways. The servlet container may set
054 * attributes to make available custom information about a request.
055 * For example, for requests made using HTTPS, the attribute
056 * <code>javax.servlet.request.X509Certificate</code> can be used to
057 * retrieve information on the certificate of the client. Attributes
058 * can also be set programatically using
059 * {@link ServletRequest#setAttribute}. This allows information to be
060 * embedded into a request before a {@link RequestDispatcher} call.
061 *
062 * <p>Attribute names should follow the same conventions as package
063 * names. This specification reserves names matching <code>java.*</code>,
064 * <code>javax.*</code>, and <code>sun.*</code>.
065 *
066 * @param name a <code>String</code> specifying the name of
067 * the attribute
068 *
069 * @return an <code>Object</code> containing the value
070 * of the attribute, or <code>null</code> if the attribute does not exist
071 */
072 public Object getAttribute(String name);
073
074 /**
075 * Returns an <code>Enumeration</code> containing the
076 * names of the attributes available to this request.
077 * This method returns an empty <code>Enumeration</code>
078 * if the request has no attributes available to it.
079 *
080 *
081 * @return an <code>Enumeration</code> of strings
082 * containing the names of the request's attributes
083 */
084 public Enumeration getAttributeNames();
085
086 /**
087 * Returns the name of the character encoding used in the body of this
088 * request. This method returns <code>null</code> if the request
089 * does not specify a character encoding
090 *
091 * @return a <code>String</code> containing the name of
092 * the chararacter encoding, or <code>null</code>
093 * if the request does not specify a character encoding
094 */
095 public String getCharacterEncoding();
096
097 /**
098 * Overrides the name of the character encoding used in the body of this
099 * request. This method must be called prior to reading request parameters
100 * or reading input using getReader().
101 *
102 * @param env a <code>String</code> containing the name of
103 * the chararacter encoding.
104 *
105 * @throws java.io.UnsupportedEncodingException if this is not a valid encoding
106 */
107 public void setCharacterEncoding(String env) throws java.io.UnsupportedEncodingException;
108
109 /**
110 * Returns the length, in bytes, of the request body
111 * and made available by the input stream, or -1 if the
112 * length is not known. For HTTP servlets, same as the value
113 * of the CGI variable CONTENT_LENGTH.
114 *
115 * @return an integer containing the length of the
116 * request body or -1 if the length is not known
117 */
118 public int getContentLength();
119
120 /**
121 * Returns the MIME type of the body of the request, or
122 * <code>null</code> if the type is not known. For HTTP servlets,
123 * same as the value of the CGI variable CONTENT_TYPE.
124 *
125 * @return a <code>String</code> containing the name
126 * of the MIME type of the request, or null if the type is not known
127 */
128 public String getContentType();
129
130 /**
131 * Retrieves the body of the request as binary data using
132 * a {@link ServletInputStream}. Either this method or
133 * {@link #getReader} may be called to read the body, not both.
134 *
135 * @return a {@link ServletInputStream} object containing
136 * the body of the request
137 *
138 * @exception IllegalStateException if the {@link #getReader} method
139 * has already been called for this request
140 *
141 * @exception IOException if an input or output exception occurred
142 */
143 public ServletInputStream getInputStream() throws IOException;
144
145 /**
146 * Returns the value of a request parameter as a <code>String</code>,
147 * or <code>null</code> if the parameter does not exist. Request parameters
148 * are extra information sent with the request. For HTTP servlets,
149 * parameters are contained in the query string or posted form data.
150 *
151 * <p>You should only use this method when you are sure the
152 * parameter has only one value. If the parameter might have
153 * more than one value, use {@link #getParameterValues}.
154 *
155 * <p>If you use this method with a multivalued
156 * parameter, the value returned is equal to the first value
157 * in the array returned by <code>getParameterValues</code>.
158 *
159 * <p>If the parameter data was sent in the request body, such as occurs
160 * with an HTTP POST request, then reading the body directly via {@link
161 * #getInputStream} or {@link #getReader} can interfere
162 * with the execution of this method.
163 *
164 * @param name a <code>String</code> specifying the
165 * name of the parameter
166 *
167 * @return a <code>String</code> representing the
168 * single value of the parameter
169 *
170 * @see #getParameterValues
171 */
172 public String getParameter(String name);
173
174 /**
175 * Returns an <code>Enumeration</code> of <code>String</code>
176 * objects containing the names of the parameters contained
177 * in this request. If the request has
178 * no parameters, the method returns an
179 * empty <code>Enumeration</code>.
180 *
181 * @return an <code>Enumeration</code> of <code>String</code>
182 * objects, each <code>String</code> containing
183 * the name of a request parameter; or an
184 * empty <code>Enumeration</code> if the
185 * request has no parameters
186 */
187 public Enumeration getParameterNames();
188
189 /**
190 * Returns an array of <code>String</code> objects containing
191 * all of the values the given request parameter has, or
192 * <code>null</code> if the parameter does not exist.
193 *
194 * <p>If the parameter has a single value, the array has a length
195 * of 1.
196 *
197 * @param name a <code>String</code> containing the name of
198 * the parameter whose value is requested
199 *
200 * @return an array of <code>String</code> objects
201 * containing the parameter's values
202 *
203 * @see #getParameter
204 */
205 public String[] getParameterValues(String name);
206
207 /**
208 * Returns a java.util.Map of the parameters of this request.
209 * Request parameters are extra information sent with the request.
210 * For HTTP servlets, parameters are contained in the query
211 * string or posted form data.
212 *
213 * @return an immutable java.util.Map containing parameter names as
214 * keys and parameter values as map values. The keys in the parameter
215 * map are of type String. The values in the parameter map are of type
216 * String array.
217 */
218 public Map getParameterMap();
219
220 /**
221 * Returns the name and version of the protocol the request uses
222 * in the form <i>protocol/majorVersion.minorVersion</i>, for
223 * example, HTTP/1.1. For HTTP servlets, the value
224 * returned is the same as the value of the CGI variable
225 * <code>SERVER_PROTOCOL</code>.
226 *
227 * @return a <code>String</code> containing the protocol
228 * name and version number
229 */
230 public String getProtocol();
231
232 /**
233 * Returns the name of the scheme used to make this request,
234 * for example,
235 * <code>http</code>, <code>https</code>, or <code>ftp</code>.
236 * Different schemes have different rules for constructing URLs,
237 * as noted in RFC 1738.
238 *
239 * @return a <code>String</code> containing the name
240 * of the scheme used to make this request
241 */
242 public String getScheme();
243
244 /**
245 * Returns the host name of the server to which the request was sent.
246 * It is the value of the part before ":" in the <code>Host</code>
247 * header, if any, or the resolved server name, or the server IP address.
248 *
249 * @return a <code>String</code> containing the name
250 * of the server
251 */
252 public String getServerName();
253
254 /**
255 * Returns the port number to which the request was sent.
256 * It is the value of the part after ":" in the <code>Host</code>
257 * header, if any, or the server port where the client connection
258 * was accepted on.
259 *
260 * @return an integer specifying the port number
261 */
262 public int getServerPort();
263
264 /**
265 * Retrieves the body of the request as character data using
266 * a <code>BufferedReader</code>. The reader translates the character
267 * data according to the character encoding used on the body.
268 * Either this method or {@link #getInputStream} may be called to read the
269 * body, not both.
270 *
271 * @return a <code>BufferedReader</code> containing the body of the request
272 *
273 * @exception UnsupportedEncodingException if the character set encoding
274 * used is not supported and the text cannot be decoded
275 *
276 * @exception IllegalStateException if {@link #getInputStream} method
277 * has been called on this request
278 *
279 * @exception IOException if an input or output exception occurred
280 *
281 * @see #getInputStream
282 */
283 public BufferedReader getReader() throws IOException;
284
285 /**
286 * Returns the Internet Protocol (IP) address of the client
287 * or last proxy that sent the request.
288 * For HTTP servlets, same as the value of the
289 * CGI variable <code>REMOTE_ADDR</code>.
290 *
291 * @return a <code>String</code> containing the
292 * IP address of the client that sent the request
293 */
294 public String getRemoteAddr();
295
296 /**
297 * Returns the fully qualified name of the client
298 * or the last proxy that sent the request.
299 * If the engine cannot or chooses not to resolve the hostname
300 * (to improve performance), this method returns the dotted-string form of
301 * the IP address. For HTTP servlets, same as the value of the CGI variable
302 * <code>REMOTE_HOST</code>.
303 *
304 * @return a <code>String</code> containing the fully
305 * qualified name of the client
306 */
307 public String getRemoteHost();
308
309 /**
310 * Stores an attribute in this request.
311 * Attributes are reset between requests. This method is most
312 * often used in conjunction with {@link RequestDispatcher}.
313 *
314 * <p>Attribute names should follow the same conventions as
315 * package names. Names beginning with <code>java.*</code>,
316 * <code>javax.*</code>, and <code>com.sun.*</code>, are
317 * reserved for use by Sun Microsystems.
318 *<br> If the object passed in is null, the effect is the same as
319 * calling {@link #removeAttribute}.
320 *
321 * @param name a <code>String</code> specifying the name of the attribute
322 *
323 * @param o the <code>Object</code> to be stored
324 */
325 public void setAttribute(String name, Object o);
326
327 /**
328 * Removes an attribute from this request. This method is not
329 * generally needed as attributes only persist as long as the request
330 * is being handled.
331 *
332 * <p>Attribute names should follow the same conventions as
333 * package names. Names beginning with <code>java.*</code>,
334 * <code>javax.*</code>, and <code>com.sun.*</code>, are
335 * reserved for use by Sun Microsystems.
336 *
337 * @param name a <code>String</code> specifying
338 * the name of the attribute to remove
339 */
340 public void removeAttribute(String name);
341
342 /**
343 * Returns the preferred <code>Locale</code> that the client will
344 * accept content in, based on the Accept-Language header.
345 * If the client request doesn't provide an Accept-Language header,
346 * this method returns the default locale for the server.
347 *
348 * @return the preferred <code>Locale</code> for the client
349 */
350 public Locale getLocale();
351
352 /**
353 * Returns an <code>Enumeration</code> of <code>Locale</code> objects
354 * indicating, in decreasing order starting with the preferred locale, the
355 * locales that are acceptable to the client based on the Accept-Language
356 * header.
357 * If the client request doesn't provide an Accept-Language header,
358 * this method returns an <code>Enumeration</code> containing one
359 * <code>Locale</code>, the default locale for the server.
360 *
361 * @return an <code>Enumeration</code> of preferred
362 * <code>Locale</code> objects for the client
363 */
364 public Enumeration getLocales();
365
366 /**
367 * Returns a boolean indicating whether this request was made using a
368 * secure channel, such as HTTPS.
369 *
370 * @return a boolean indicating if the request was made using a
371 * secure channel
372 */
373 public boolean isSecure();
374
375 /**
376 * Returns a {@link RequestDispatcher} object that acts as a wrapper for
377 * the resource located at the given path.
378 * A <code>RequestDispatcher</code> object can be used to forward
379 * a request to the resource or to include the resource in a response.
380 * The resource can be dynamic or static.
381 *
382 * <p>The pathname specified may be relative, although it cannot extend
383 * outside the current servlet context. If the path begins with
384 * a "/" it is interpreted as relative to the current context root.
385 * This method returns <code>null</code> if the servlet container
386 * cannot return a <code>RequestDispatcher</code>.
387 *
388 * <p>The difference between this method and {@link
389 * ServletContext#getRequestDispatcher} is that this method can take a
390 * relative path.
391 *
392 * @param path a <code>String</code> specifying the pathname to the
393 * resource. If it is relative, it must be relative against the
394 * current servlet.
395 *
396 * @return a <code>RequestDispatcher</code> object that acts as a
397 * wrapper for the resource at the specified path, or <code>null</code>
398 * if the servlet container cannot return a
399 * <code>RequestDispatcher</code>
400 *
401 * @see RequestDispatcher
402 * @see ServletContext#getRequestDispatcher
403 */
404 public RequestDispatcher getRequestDispatcher(String path);
405
406 /**
407 * @deprecated As of Version 2.1 of the Java Servlet API,
408 * use {@link ServletContext#getRealPath} instead.
409 */
410 public String getRealPath(String path);
411
412 /**
413 * Returns the Internet Protocol (IP) source port of the client
414 * or last proxy that sent the request.
415 *
416 * @since Servlet 2.4
417 */
418 public int getRemotePort();
419
420 /**
421 * Returns the host name of the Internet Protocol (IP) interface on
422 * which the request was received.
423 *
424 * @return a <code>String</code> containing the host
425 * name of the IP on which the request was received.
426 *
427 * @since Servlet 2.4
428 */
429 public String getLocalName();
430
431 /**
432 * Returns the Internet Protocol (IP) address of the interface on
433 * which the request was received.
434 *
435 * @return a <code>String</code> containing the
436 * IP address on which the request was received.
437 *
438 * @since Servlet 2.4
439 */
440 public String getLocalAddr();
441
442 /**
443 * Returns the Internet Protocol (IP) port number of the interface
444 * on which the request was received.
445 *
446 * @return an integer specifying the port number
447 *
448 * @since Servlet 2.4
449 */
450 public int getLocalPort();
451 }
452