1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. 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 package javax.servlet.http;
18
19 import java.text.MessageFormat;
20 import java.util.ResourceBundle;
21
22 /**
23 *
24 * Creates a cookie, a small amount of information sent by a servlet to
25 * a Web browser, saved by the browser, and later sent back to the server.
26 * A cookie's value can uniquely
27 * identify a client, so cookies are commonly used for session management.
28 *
29 * <p>A cookie has a name, a single value, and optional attributes
30 * such as a comment, path and domain qualifiers, a maximum age, and a
31 * version number. Some Web browsers have bugs in how they handle the
32 * optional attributes, so use them sparingly to improve the interoperability
33 * of your servlets.
34 *
35 * <p>The servlet sends cookies to the browser by using the
36 * {@link HttpServletResponse#addCookie} method, which adds
37 * fields to HTTP response headers to send cookies to the
38 * browser, one at a time. The browser is expected to
39 * support 20 cookies for each Web server, 300 cookies total, and
40 * may limit cookie size to 4 KB each.
41 *
42 * <p>The browser returns cookies to the servlet by adding
43 * fields to HTTP request headers. Cookies can be retrieved
44 * from a request by using the {@link HttpServletRequest#getCookies} method.
45 * Several cookies might have the same name but different path attributes.
46 *
47 * <p>Cookies affect the caching of the Web pages that use them.
48 * HTTP 1.0 does not cache pages that use cookies created with
49 * this class. This class does not support the cache control
50 * defined with HTTP 1.1.
51 *
52 * <p>This class supports both the Version 0 (by Netscape) and Version 1
53 * (by RFC 2109) cookie specifications. By default, cookies are
54 * created using Version 0 to ensure the best interoperability.
55 *
56 *
57 * @author Various
58 * @version $Version$
59 *
60 */
61
62 // XXX would implement java.io.Serializable too, but can't do that
63 // so long as sun.servlet.* must run on older JDK 1.02 JVMs which
64 // don't include that support.
65
66 public class Cookie implements Cloneable {
67
68 private static final String LSTRING_FILE =
69 "javax.servlet.http.LocalStrings";
70 private static ResourceBundle lStrings =
71 ResourceBundle.getBundle(LSTRING_FILE);
72
73 //
74 // The value of the cookie itself.
75 //
76
77 private String name; // NAME= ... "$Name" style is reserved
78 private String value; // value of NAME
79
80 //
81 // Attributes encoded in the header's cookie fields.
82 //
83
84 private String comment; // ;Comment=VALUE ... describes cookie's use
85 // ;Discard ... implied by maxAge < 0
86 private String domain; // ;Domain=VALUE ... domain that sees cookie
87 private int maxAge = -1; // ;Max-Age=VALUE ... cookies auto-expire
88 private String path; // ;Path=VALUE ... URLs that see the cookie
89 private boolean secure; // ;Secure ... e.g. use SSL
90 private int version = 0; // ;Version=1 ... means RFC 2109++ style
91
92
93
94 /**
95 * Constructs a cookie with a specified name and value.
96 *
97 * <p>The name must conform to RFC 2109. That means it can contain
98 * only ASCII alphanumeric characters and cannot contain commas,
99 * semicolons, or white space or begin with a $ character. The cookie's
100 * name cannot be changed after creation.
101 *
102 * <p>The value can be anything the server chooses to send. Its
103 * value is probably of interest only to the server. The cookie's
104 * value can be changed after creation with the
105 * <code>setValue</code> method.
106 *
107 * <p>By default, cookies are created according to the Netscape
108 * cookie specification. The version can be changed with the
109 * <code>setVersion</code> method.
110 *
111 *
112 * @param name a <code>String</code> specifying the name of the cookie
113 *
114 * @param value a <code>String</code> specifying the value of the cookie
115 *
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 */
124
125 public Cookie(String name, String value) {
126 if (!isToken(name)
127 || name.equalsIgnoreCase("Comment") // rfc2019
128 || name.equalsIgnoreCase("Discard") // 2019++
129 || name.equalsIgnoreCase("Domain")
130 || name.equalsIgnoreCase("Expires") // (old cookies)
131 || name.equalsIgnoreCase("Max-Age") // rfc2019
132 || name.equalsIgnoreCase("Path")
133 || name.equalsIgnoreCase("Secure")
134 || name.equalsIgnoreCase("Version")
135 || name.startsWith("$")
136 ) {
137 String errMsg = lStrings.getString("err.cookie_name_is_token");
138 Object[] errArgs = new Object[1];
139 errArgs[0] = name;
140 errMsg = MessageFormat.format(errMsg, errArgs);
141 throw new IllegalArgumentException(errMsg);
142 }
143
144 this.name = name;
145 this.value = value;
146 }
147
148
149
150
151
152 /**
153 *
154 * Specifies a comment that describes a cookie's purpose.
155 * The comment is useful if the browser presents the cookie
156 * to the user. Comments
157 * are not supported by Netscape Version 0 cookies.
158 *
159 * @param purpose a <code>String</code> specifying the comment
160 * to display to the user
161 *
162 * @see #getComment
163 *
164 */
165
166 public void setComment(String purpose) {
167 comment = purpose;
168 }
169
170
171
172
173 /**
174 * Returns the comment describing the purpose of this cookie, or
175 * <code>null</code> if the cookie has no comment.
176 *
177 * @return a <code>String</code> containing the comment,
178 * or <code>null</code> if none
179 *
180 * @see #setComment
181 *
182 */
183
184 public String getComment() {
185 return comment;
186 }
187
188
189
190
191
192 /**
193 *
194 * Specifies the domain within which this cookie should be presented.
195 *
196 * <p>The form of the domain name is specified by RFC 2109. A domain
197 * name begins with a dot (<code>.foo.com</code>) and means that
198 * the cookie is visible to servers in a specified Domain Name System
199 * (DNS) zone (for example, <code>www.foo.com</code>, but not
200 * <code>a.b.foo.com</code>). By default, cookies are only returned
201 * to the server that sent them.
202 *
203 *
204 * @param pattern a <code>String</code> containing the domain name
205 * within which this cookie is visible;
206 * form is according to RFC 2109
207 *
208 * @see #getDomain
209 *
210 */
211
212 public void setDomain(String pattern) {
213 domain = pattern.toLowerCase(); // IE allegedly needs this
214 }
215
216
217
218
219
220 /**
221 * Returns the domain name set for this cookie. The form of
222 * the domain name is set by RFC 2109.
223 *
224 * @return a <code>String</code> containing the domain name
225 *
226 * @see #setDomain
227 *
228 */
229
230 public String getDomain() {
231 return domain;
232 }
233
234
235
236
237 /**
238 * Sets the maximum age of the cookie in seconds.
239 *
240 * <p>A positive value indicates that the cookie will expire
241 * after that many seconds have passed. Note that the value is
242 * the <i>maximum</i> age when the cookie will expire, not the cookie's
243 * current age.
244 *
245 * <p>A negative value means
246 * that the cookie is not stored persistently and will be deleted
247 * when the Web browser exits. A zero value causes the cookie
248 * to be deleted.
249 *
250 * @param expiry an integer specifying the maximum age of the
251 * cookie in seconds; if negative, means
252 * the cookie is not stored; if zero, deletes
253 * the cookie
254 *
255 *
256 * @see #getMaxAge
257 *
258 */
259
260 public void setMaxAge(int expiry) {
261 maxAge = expiry;
262 }
263
264
265
266
267 /**
268 * Returns the maximum age of the cookie, specified in seconds,
269 * By default, <code>-1</code> indicating the cookie will persist
270 * until browser shutdown.
271 *
272 *
273 * @return an integer specifying the maximum age of the
274 * cookie in seconds; if negative, means
275 * the cookie persists until browser shutdown
276 *
277 *
278 * @see #setMaxAge
279 *
280 */
281
282 public int getMaxAge() {
283 return maxAge;
284 }
285
286
287
288
289 /**
290 * Specifies a path for the cookie
291 * to which the client should return the cookie.
292 *
293 * <p>The cookie is visible to all the pages in the directory
294 * you specify, and all the pages in that directory's subdirectories.
295 * A cookie's path must include the servlet that set the cookie,
296 * for example, <i>/catalog</i>, which makes the cookie
297 * visible to all directories on the server under <i>/catalog</i>.
298 *
299 * <p>Consult RFC 2109 (available on the Internet) for more
300 * information on setting path names for cookies.
301 *
302 *
303 * @param uri a <code>String</code> specifying a path
304 *
305 *
306 * @see #getPath
307 *
308 */
309
310 public void setPath(String uri) {
311 path = uri;
312 }
313
314
315
316
317 /**
318 * Returns the path on the server
319 * to which the browser returns this cookie. The
320 * cookie is visible to all subpaths on the server.
321 *
322 *
323 * @return a <code>String</code> specifying a path that contains
324 * a servlet name, for example, <i>/catalog</i>
325 *
326 * @see #setPath
327 *
328 */
329
330 public String getPath() {
331 return path;
332 }
333
334
335
336
337
338 /**
339 * Indicates to the browser whether the cookie should only be sent
340 * using a secure protocol, such as HTTPS or SSL.
341 *
342 * <p>The default value is <code>false</code>.
343 *
344 * @param flag if <code>true</code>, sends the cookie from the browser
345 * to the server only when using a secure protocol;
346 * if <code>false</code>, sent on any protocol
347 *
348 * @see #getSecure
349 *
350 */
351
352 public void setSecure(boolean flag) {
353 secure = flag;
354 }
355
356
357
358
359 /**
360 * Returns <code>true</code> if the browser is sending cookies
361 * only over a secure protocol, or <code>false</code> if the
362 * browser can send cookies using any protocol.
363 *
364 * @return <code>true</code> if the browser uses a secure protocol;
365 * otherwise, <code>true</code>
366 *
367 * @see #setSecure
368 *
369 */
370
371 public boolean getSecure() {
372 return secure;
373 }
374
375
376
377
378
379 /**
380 * Returns the name of the cookie. The name cannot be changed after
381 * creation.
382 *
383 * @return a <code>String</code> specifying the cookie's name
384 *
385 */
386
387 public String getName() {
388 return name;
389 }
390
391
392
393
394
395 /**
396 *
397 * Assigns a new value to a cookie after the cookie is created.
398 * If you use a binary value, you may want to use BASE64 encoding.
399 *
400 * <p>With Version 0 cookies, values should not contain white
401 * space, brackets, parentheses, equals signs, commas,
402 * double quotes, slashes, question marks, at signs, colons,
403 * and semicolons. Empty values may not behave the same way
404 * on all browsers.
405 *
406 * @param newValue a <code>String</code> specifying the new value
407 *
408 *
409 * @see #getValue
410 * @see Cookie
411 *
412 */
413
414 public void setValue(String newValue) {
415 value = newValue;
416 }
417
418
419
420
421 /**
422 * Returns the value of the cookie.
423 *
424 * @return a <code>String</code> containing the cookie's
425 * present value
426 *
427 * @see #setValue
428 * @see Cookie
429 *
430 */
431
432 public String getValue() {
433 return value;
434 }
435
436
437
438
439 /**
440 * Returns the version of the protocol this cookie complies
441 * with. Version 1 complies with RFC 2109,
442 * and version 0 complies with the original
443 * cookie specification drafted by Netscape. Cookies provided
444 * by a browser use and identify the browser's cookie version.
445 *
446 *
447 * @return 0 if the cookie complies with the
448 * original Netscape specification; 1
449 * if the cookie complies with RFC 2109
450 *
451 * @see #setVersion
452 *
453 */
454
455 public int getVersion() {
456 return version;
457 }
458
459
460
461
462 /**
463 * Sets the version of the cookie protocol this cookie complies
464 * with. Version 0 complies with the original Netscape cookie
465 * specification. Version 1 complies with RFC 2109.
466 *
467 * <p>Since RFC 2109 is still somewhat new, consider
468 * version 1 as experimental; do not use it yet on production sites.
469 *
470 *
471 * @param v 0 if the cookie should comply with
472 * the original Netscape specification;
473 * 1 if the cookie should comply with RFC 2109
474 *
475 * @see #getVersion
476 *
477 */
478
479 public void setVersion(int v) {
480 version = v;
481 }
482
483 // Note -- disabled for now to allow full Netscape compatibility
484 // from RFC 2068, token special case characters
485 //
486 // private static final String tspecials = "()<>@,;:\\\"/[]?={} \t";
487
488 private static final String tspecials = ",; ";
489
490
491
492
493 /*
494 * Tests a string and returns true if the string counts as a
495 * reserved token in the Java language.
496 *
497 * @param value the <code>String</code> to be tested
498 *
499 * @return <code>true</code> if the <code>String</code> is
500 * a reserved token; <code>false</code>
501 * if it is not
502 */
503
504 private boolean isToken(String value) {
505 int len = value.length();
506
507 for (int i = 0; i < len; i++) {
508 char c = value.charAt(i);
509
510 if (c < 0x20 || c >= 0x7f || tspecials.indexOf(c) != -1)
511 return false;
512 }
513 return true;
514 }
515
516
517
518
519
520
521 /**
522 *
523 * Overrides the standard <code>java.lang.Object.clone</code>
524 * method to return a copy of this cookie.
525 *
526 *
527 */
528
529 public Object clone() {
530 try {
531 return super.clone();
532 } catch (CloneNotSupportedException e) {
533 throw new RuntimeException(e.getMessage());
534 }
535 }
536 }
537