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 package javax.servlet.http;
021
022 import java.io.Serializable;
023 import java.text.MessageFormat;
024 import java.util.ResourceBundle;
025
026 /**
027 * Creates a cookie, a small amount of information sent by a servlet to
028 * a Web browser, saved by the browser, and later sent back to the server.
029 * A cookie's value can uniquely
030 * identify a client, so cookies are commonly used for session management.
031 * <p/>
032 * <p>A cookie has a name, a single value, and optional attributes
033 * such as a comment, path and domain qualifiers, a maximum age, and a
034 * version number. Some Web browsers have bugs in how they handle the
035 * optional attributes, so use them sparingly to improve the interoperability
036 * of your servlets.
037 * <p/>
038 * <p>The servlet sends cookies to the browser by using the
039 * {@link HttpServletResponse#addCookie} method, which adds
040 * fields to HTTP response headers to send cookies to the
041 * browser, one at a time. The browser is expected to
042 * support 20 cookies for each Web server, 300 cookies total, and
043 * may limit cookie size to 4 KB each.
044 * <p/>
045 * <p>The browser returns cookies to the servlet by adding
046 * fields to HTTP request headers. Cookies can be retrieved
047 * from a request by using the {@link HttpServletRequest#getCookies} method.
048 * Several cookies might have the same name but different path attributes.
049 * <p/>
050 * <p>Cookies affect the caching of the Web pages that use them.
051 * HTTP 1.0 does not cache pages that use cookies created with
052 * this class. This class does not support the cache control
053 * defined with HTTP 1.1.
054 * <p/>
055 * <p>This class supports both the Version 0 (by Netscape) and Version 1
056 * (by RFC 2109) cookie specifications. By default, cookies are
057 * created using Version 0 to ensure the best interoperability.
058 *
059 * @version $Rev: 901916 $ $Date: 2010-01-21 18:12:17 -0500 (Thu, 21 Jan 2010) $
060 */
061
062 public class Cookie implements Cloneable, Serializable {
063 private static final long serialVersionUID = -6454587001725327448L;
064
065 private static final String LSTRING_FILE =
066 "javax.servlet.http.LocalStrings";
067 private static ResourceBundle lStrings =
068 ResourceBundle.getBundle(LSTRING_FILE);
069
070 // Note -- disabled for now to allow full Netscape compatibility
071 // from RFC 2068, token special case characters
072 //
073 // private static final String tspecials = "()<>@,;:\\\"/[]?={} \t";
074
075 private static final String tspecials = ",; ";
076
077 //
078 // The value of the cookie itself.
079 //
080
081 private String name; // NAME= ... "$Name" style is reserved
082 private String value; // value of NAME
083
084 //
085 // Attributes encoded in the header's cookie fields.
086 //
087
088 private String comment; // ;Comment=VALUE ... describes cookie's use
089 // ;Discard ... implied by maxAge < 0
090 private String domain; // ;Domain=VALUE ... domain that sees cookie
091 private int maxAge = -1; // ;Max-Age=VALUE ... cookies auto-expire
092 private String path; // ;Path=VALUE ... URLs that see the cookie
093 private boolean secure; // ;Secure ... e.g. use SSL
094 private int version = 0; // ;Version=1 ... means RFC 2109++ style
095 private boolean httpOnly;
096
097 /**
098 * Constructs a cookie with a specified name and value.
099 * <p/>
100 * <p>The name must conform to RFC 2109. That means it can contain
101 * only ASCII alphanumeric characters and cannot contain commas,
102 * semicolons, or white space or begin with a $ character. The cookie's
103 * name cannot be changed after creation.
104 * <p/>
105 * <p>The value can be anything the server chooses to send. Its
106 * value is probably of interest only to the server. The cookie's
107 * value can be changed after creation with the
108 * <code>setValue</code> method.
109 * <p/>
110 * <p>By default, cookies are created according to the Netscape
111 * cookie specification. The version can be changed with the
112 * <code>setVersion</code> method.
113 *
114 * @param name a <code>String</code> specifying the name of the cookie
115 * @param value a <code>String</code> specifying the value of the cookie
116 * @throws IllegalArgumentException if the cookie name contains illegal characters
117 * (for example, a comma, space, or semicolon)
118 * or it is one of the tokens reserved for use
119 * by the cookie protocol
120 * @see #setValue
121 * @see #setVersion
122 */
123 public Cookie(String name, String value) {
124 if (!isToken(name)
125 || name.equalsIgnoreCase("Comment") // rfc2019
126 || name.equalsIgnoreCase("Discard") // 2019++
127 || name.equalsIgnoreCase("Domain")
128 || name.equalsIgnoreCase("Expires") // (old cookies)
129 || name.equalsIgnoreCase("Max-Age") // rfc2019
130 || name.equalsIgnoreCase("Path")
131 || name.equalsIgnoreCase("Secure")
132 || name.equalsIgnoreCase("Version")
133 || name.startsWith("$")
134 ) {
135 String errMsg = lStrings.getString("err.cookie_name_is_token");
136 Object[] errArgs = new Object[1];
137 errArgs[0] = name;
138 errMsg = MessageFormat.format(errMsg, errArgs);
139 throw new IllegalArgumentException(errMsg);
140 }
141
142 this.name = name;
143 this.value = value;
144 }
145
146 /**
147 * Specifies a comment that describes a cookie's purpose.
148 * The comment is useful if the browser presents the cookie
149 * to the user. Comments
150 * are not supported by Netscape Version 0 cookies.
151 *
152 * @param purpose a <code>String</code> specifying the comment
153 * to display to the user
154 * @see #getComment
155 */
156 public void setComment(String purpose) {
157 comment = purpose;
158 }
159
160 /**
161 * Returns the comment describing the purpose of this cookie, or
162 * <code>null</code> if the cookie has no comment.
163 *
164 * @return a <code>String</code> containing the comment,
165 * or <code>null</code> if none
166 * @see #setComment
167 */
168 public String getComment() {
169 return comment;
170 }
171
172 /**
173 * Specifies the domain within which this cookie should be presented.
174 * <p/>
175 * <p>The form of the domain name is specified by RFC 2109. A domain
176 * name begins with a dot (<code>.foo.com</code>) and means that
177 * the cookie is visible to servers in a specified Domain Name System
178 * (DNS) zone (for example, <code>www.foo.com</code>, but not
179 * <code>a.b.foo.com</code>). By default, cookies are only returned
180 * to the server that sent them.
181 *
182 * @param pattern a <code>String</code> containing the domain name
183 * within which this cookie is visible;
184 * form is according to RFC 2109
185 * @see #getDomain
186 */
187 public void setDomain(String pattern) {
188 domain = pattern.toLowerCase(); // IE allegedly needs this
189 }
190
191 /**
192 * Returns the domain name set for this cookie. The form of
193 * the domain name is set by RFC 2109.
194 *
195 * @return a <code>String</code> containing the domain name
196 * @see #setDomain
197 */
198 public String getDomain() {
199 return domain;
200 }
201
202 /**
203 * Sets the maximum age of the cookie in seconds.
204 * <p/>
205 * <p>A positive value indicates that the cookie will expire
206 * after that many seconds have passed. Note that the value is
207 * the <i>maximum</i> age when the cookie will expire, not the cookie's
208 * current age.
209 * <p/>
210 * <p>A negative value means
211 * that the cookie is not stored persistently and will be deleted
212 * when the Web browser exits. A zero value causes the cookie
213 * to be deleted.
214 *
215 * @param expiry an integer specifying the maximum age of the
216 * cookie in seconds; if negative, means
217 * the cookie is not stored; if zero, deletes
218 * the cookie
219 * @see #getMaxAge
220 */
221 public void setMaxAge(int expiry) {
222 maxAge = expiry;
223 }
224
225 /**
226 * Returns the maximum age of the cookie, specified in seconds,
227 * By default, <code>-1</code> indicating the cookie will persist
228 * until browser shutdown.
229 *
230 * @return an integer specifying the maximum age of the
231 * cookie in seconds; if negative, means
232 * the cookie persists until browser shutdown
233 * @see #setMaxAge
234 */
235 public int getMaxAge() {
236 return maxAge;
237 }
238
239 /**
240 * Specifies a path for the cookie
241 * to which the client should return the cookie.
242 * <p/>
243 * <p>The cookie is visible to all the pages in the directory
244 * you specify, and all the pages in that directory's subdirectories.
245 * A cookie's path must include the servlet that set the cookie,
246 * for example, <i>/catalog</i>, which makes the cookie
247 * visible to all directories on the server under <i>/catalog</i>.
248 * <p/>
249 * <p>Consult RFC 2109 (available on the Internet) for more
250 * information on setting path names for cookies.
251 *
252 * @param uri a <code>String</code> specifying a path
253 * @see #getPath
254 */
255 public void setPath(String uri) {
256 path = uri;
257 }
258
259 /**
260 * Returns the path on the server
261 * to which the browser returns this cookie. The
262 * cookie is visible to all subpaths on the server.
263 *
264 * @return a <code>String</code> specifying a path that contains
265 * a servlet name, for example, <i>/catalog</i>
266 * @see #setPath
267 */
268 public String getPath() {
269 return path;
270 }
271
272 /**
273 * Indicates to the browser whether the cookie should only be sent
274 * using a secure protocol, such as HTTPS or SSL.
275 * <p/>
276 * <p>The default value is <code>false</code>.
277 *
278 * @param flag if <code>true</code>, sends the cookie from the browser
279 * to the server only when using a secure protocol;
280 * if <code>false</code>, sent on any protocol
281 * @see #getSecure
282 */
283 public void setSecure(boolean flag) {
284 secure = flag;
285 }
286
287 /**
288 * Returns <code>true</code> if the browser is sending cookies
289 * only over a secure protocol, or <code>false</code> if the
290 * browser can send cookies using any protocol.
291 *
292 * @return <code>true</code> if the browser uses a secure protocol;
293 * otherwise, <code>true</code>
294 * @see #setSecure
295 */
296 public boolean getSecure() {
297 return secure;
298 }
299
300 /**
301 * Returns the name of the cookie. The name cannot be changed after
302 * creation.
303 *
304 * @return a <code>String</code> specifying the cookie's name
305 */
306 public String getName() {
307 return name;
308 }
309
310 /**
311 * Assigns a new value to a cookie after the cookie is created.
312 * If you use a binary value, you may want to use BASE64 encoding.
313 * <p/>
314 * <p>With Version 0 cookies, values should not contain white
315 * space, brackets, parentheses, equals signs, commas,
316 * double quotes, slashes, question marks, at signs, colons,
317 * and semicolons. Empty values may not behave the same way
318 * on all browsers.
319 *
320 * @param newValue a <code>String</code> specifying the new value
321 * @see #getValue
322 * @see Cookie
323 */
324 public void setValue(String newValue) {
325 value = newValue;
326 }
327
328 /**
329 * Returns the value of the cookie.
330 *
331 * @return a <code>String</code> containing the cookie's
332 * present value
333 * @see #setValue
334 * @see Cookie
335 */
336 public String getValue() {
337 return value;
338 }
339
340 /**
341 * Returns the version of the protocol this cookie complies
342 * with. Version 1 complies with RFC 2109,
343 * and version 0 complies with the original
344 * cookie specification drafted by Netscape. Cookies provided
345 * by a browser use and identify the browser's cookie version.
346 *
347 * @return 0 if the cookie complies with the
348 * original Netscape specification; 1
349 * if the cookie complies with RFC 2109
350 * @see #setVersion
351 */
352 public int getVersion() {
353 return version;
354 }
355
356 /**
357 * Sets the version of the cookie protocol this cookie complies
358 * with. Version 0 complies with the original Netscape cookie
359 * specification. Version 1 complies with RFC 2109.
360 * <p/>
361 * <p>Since RFC 2109 is still somewhat new, consider
362 * version 1 as experimental; do not use it yet on production sites.
363 *
364 * @param v 0 if the cookie should comply with
365 * the original Netscape specification;
366 * 1 if the cookie should comply with RFC 2109
367 * @see #getVersion
368 */
369 public void setVersion(int v) {
370 version = v;
371 }
372
373 /*
374 * Tests a string and returns true if the string counts as a
375 * reserved token in the Java language.
376 *
377 * @param value the <code>String</code> to be tested
378 *
379 * @return <code>true</code> if the <code>String</code> is
380 * a reserved token; <code>false</code>
381 * if it is not
382 */
383 private boolean isToken(String value) {
384 int len = value.length();
385
386 for (int i = 0; i < len; i++) {
387 char c = value.charAt(i);
388
389 if (c < 0x20 || c >= 0x7f || tspecials.indexOf(c) != -1)
390 return false;
391 }
392 return true;
393 }
394
395 /**
396 * Overrides the standard <code>java.lang.Object.clone</code>
397 * method to return a copy of this cookie.
398 */
399 public Object clone() {
400 try {
401 return super.clone();
402 } catch (CloneNotSupportedException e) {
403 throw new RuntimeException(e.getMessage());
404 }
405 }
406
407 /**
408 * @return whether cookie is http only
409 * @since servlet 3.0
410 */
411 public boolean isHttpOnly() {
412 return httpOnly;
413 }
414
415 /**
416 * @param httpOnly httpOnly setting
417 * @since servlet 3.0
418 */
419 public void setHttpOnly(boolean httpOnly) {
420 this.httpOnly = httpOnly;
421 }
422 }
423