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.http; 027 028 import java.text.MessageFormat; 029 import java.util.ResourceBundle; 030 031 /** 032 * Creates a cookie, a small amount of information sent by a servlet to 033 * a Web browser, saved by the browser, and later sent back to the server. 034 * A cookie's value can uniquely 035 * identify a client, so cookies are commonly used for session management. 036 * 037 * <p>A cookie has a name, a single value, and optional attributes 038 * such as a comment, path and domain qualifiers, a maximum age, and a 039 * version number. Some Web browsers have bugs in how they handle the 040 * optional attributes, so use them sparingly to improve the interoperability 041 * of your servlets. 042 * 043 * <p>The servlet sends cookies to the browser by using the 044 * {@link HttpServletResponse#addCookie} method, which adds 045 * fields to HTTP response headers to send cookies to the 046 * browser, one at a time. The browser is expected to 047 * support 20 cookies for each Web server, 300 cookies total, and 048 * may limit cookie size to 4 KB each. 049 * 050 * <p>The browser returns cookies to the servlet by adding 051 * fields to HTTP request headers. Cookies can be retrieved 052 * from a request by using the {@link HttpServletRequest#getCookies} method. 053 * Several cookies might have the same name but different path attributes. 054 * 055 * <p>Cookies affect the caching of the Web pages that use them. 056 * HTTP 1.0 does not cache pages that use cookies created with 057 * this class. This class does not support the cache control 058 * defined with HTTP 1.1. 059 * 060 * <p>This class supports both the Version 0 (by Netscape) and Version 1 061 * (by RFC 2109) cookie specifications. By default, cookies are 062 * created using Version 0 to ensure the best interoperability. 063 * 064 * @version $Rev: 467553 $ $Date: 2006-10-25 06:01:51 +0200 (Mi, 25. Okt 2006) $ 065 */ 066 067 // XXX would implement java.io.Serializable too, but can't do that 068 // so long as sun.servlet.* must run on older JDK 1.02 JVMs which 069 // don't include that support. 070 071 public class Cookie implements Cloneable { 072 private static final String LSTRING_FILE = "javax.servlet.http.LocalStrings"; 073 private static ResourceBundle lStrings = ResourceBundle.getBundle(LSTRING_FILE); 074 075 // 076 // The value of the cookie itself. 077 // 078 079 private String name; // NAME= ... "$Name" style is reserved 080 private String value; // value of NAME 081 082 // 083 // Attributes encoded in the header's cookie fields. 084 // 085 086 private String comment; // ;Comment=VALUE ... describes cookie's use 087 // ;Discard ... implied by maxAge < 0 088 private String domain; // ;Domain=VALUE ... domain that sees cookie 089 private int maxAge = -1; // ;Max-Age=VALUE ... cookies auto-expire 090 private String path; // ;Path=VALUE ... URLs that see the cookie 091 private boolean secure; // ;Secure ... e.g. use SSL 092 private int version = 0; // ;Version=1 ... means RFC 2109++ style 093 094 095 /** 096 * Constructs a cookie with a specified name and value. 097 * 098 * <p>The name must conform to RFC 2109. That means it can contain 099 * only ASCII alphanumeric characters and cannot contain commas, 100 * semicolons, or white space or begin with a $ character. The cookie's 101 * name cannot be changed after creation. 102 * 103 * <p>The value can be anything the server chooses to send. Its 104 * value is probably of interest only to the server. The cookie's 105 * value can be changed after creation with the 106 * <code>setValue</code> method. 107 * 108 * <p>By default, cookies are created according to the Netscape 109 * cookie specification. The version can be changed with the 110 * <code>setVersion</code> method. 111 * 112 * 113 * @param name a <code>String</code> specifying the name of the cookie 114 * 115 * @param value a <code>String</code> specifying the value of the cookie 116 * 117 * @throws IllegalArgumentException if the cookie name contains illegal characters 118 * (for example, a comma, space, or semicolon) or it is one of the tokens reserved for use 119 * by the cookie protocol 120 * 121 * @see #setValue 122 * @see #setVersion 123 */ 124 public Cookie(String name, String value) { 125 if (!isToken(name) 126 || name.equalsIgnoreCase("Comment") // rfc2019 127 || name.equalsIgnoreCase("Discard") // 2019++ 128 || name.equalsIgnoreCase("Domain") 129 || name.equalsIgnoreCase("Expires") // (old cookies) 130 || name.equalsIgnoreCase("Max-Age") // rfc2019 131 || name.equalsIgnoreCase("Path") 132 || name.equalsIgnoreCase("Secure") 133 || name.equalsIgnoreCase("Version") 134 || name.startsWith("$") 135 ) { 136 String errMsg = lStrings.getString("err.cookie_name_is_token"); 137 Object[] errArgs = new Object[1]; 138 errArgs[0] = name; 139 errMsg = MessageFormat.format(errMsg, errArgs); 140 throw new IllegalArgumentException(errMsg); 141 } 142 143 this.name = name; 144 this.value = value; 145 } 146 147 /** 148 * Specifies a comment that describes a cookie's purpose. 149 * The comment is useful if the browser presents the cookie 150 * to the user. Comments 151 * are not supported by Netscape Version 0 cookies. 152 * 153 * @param purpose a <code>String</code> specifying the comment 154 * to display to the user 155 * 156 * @see #getComment 157 */ 158 public void setComment(String purpose) { 159 comment = purpose; 160 } 161 162 /** 163 * Returns the comment describing the purpose of this cookie, or 164 * <code>null</code> if the cookie has no comment. 165 * 166 * @return a <code>String</code> containing the comment, 167 * or <code>null</code> if none 168 * 169 * @see #setComment 170 */ 171 public String getComment() { 172 return comment; 173 } 174 175 /** 176 * Specifies the domain within which this cookie should be presented. 177 * 178 * <p>The form of the domain name is specified by RFC 2109. A domain 179 * name begins with a dot (<code>.foo.com</code>) and means that 180 * the cookie is visible to servers in a specified Domain Name System 181 * (DNS) zone (for example, <code>www.foo.com</code>, but not 182 * <code>a.b.foo.com</code>). By default, cookies are only returned 183 * to the server that sent them. 184 * 185 * @param pattern a <code>String</code> containing the domain name 186 * within which this cookie is visible; form is according to RFC 2109 187 * 188 * @see #getDomain 189 */ 190 public void setDomain(String pattern) { 191 domain = pattern.toLowerCase(); // IE allegedly needs this 192 } 193 194 /** 195 * Returns the domain name set for this cookie. The form of 196 * the domain name is set by RFC 2109. 197 * 198 * @return a <code>String</code> containing the domain name 199 * 200 * @see #setDomain 201 */ 202 public String getDomain() { 203 return domain; 204 } 205 206 /** 207 * Sets the maximum age of the cookie in seconds. 208 * 209 * <p>A positive value indicates that the cookie will expire 210 * after that many seconds have passed. Note that the value is 211 * the <i>maximum</i> age when the cookie will expire, not the cookie's 212 * current age. 213 * 214 * <p>A negative value means 215 * that the cookie is not stored persistently and will be deleted 216 * when the Web browser exits. A zero value causes the cookie 217 * to be deleted. 218 * 219 * @param expiry an integer specifying the maximum age of the 220 * cookie in seconds; if negative, means the cookie is not stored; 221 * if zero, deletes the cookie 222 * 223 * @see #getMaxAge 224 */ 225 public void setMaxAge(int expiry) { 226 maxAge = expiry; 227 } 228 229 /** 230 * Returns the maximum age of the cookie, specified in seconds, 231 * By default, <code>-1</code> indicating the cookie will persist 232 * until browser shutdown. 233 * 234 * @return an integer specifying the maximum age of the 235 * cookie in seconds; if negative, means the cookie persists 236 * until browser shutdown 237 * 238 * @see #setMaxAge 239 */ 240 public int getMaxAge() { 241 return maxAge; 242 } 243 244 /** 245 * Specifies a path for the cookie 246 * to which the client should return the cookie. 247 * 248 * <p>The cookie is visible to all the pages in the directory 249 * you specify, and all the pages in that directory's subdirectories. 250 * A cookie's path must include the servlet that set the cookie, 251 * for example, <i>/catalog</i>, which makes the cookie 252 * visible to all directories on the server under <i>/catalog</i>. 253 * 254 * <p>Consult RFC 2109 (available on the Internet) for more 255 * information on setting path names for cookies. 256 * 257 * @param uri a <code>String</code> specifying a path 258 * 259 * @see #getPath 260 */ 261 public void setPath(String uri) { 262 path = uri; 263 } 264 265 /** 266 * Returns the path on the server 267 * to which the browser returns this cookie. The 268 * cookie is visible to all subpaths on the server. 269 * 270 * @return a <code>String</code> specifying a path that contains 271 * a servlet name, for example, <i>/catalog</i> 272 * 273 * @see #setPath 274 */ 275 public String getPath() { 276 return path; 277 } 278 279 /** 280 * Indicates to the browser whether the cookie should only be sent 281 * using a secure protocol, such as HTTPS or SSL. 282 * 283 * <p>The default value is <code>false</code>. 284 * 285 * @param flag if <code>true</code>, sends the cookie from the browser 286 * to the server only when using a secure protocol; if <code>false</code>, 287 * sent on any protocol 288 * 289 * @see #getSecure 290 */ 291 public void setSecure(boolean flag) { 292 secure = flag; 293 } 294 295 /** 296 * Returns <code>true</code> if the browser is sending cookies 297 * only over a secure protocol, or <code>false</code> if the 298 * browser can send cookies using any protocol. 299 * 300 * @return <code>true</code> if the browser uses a secure protocol; 301 * otherwise, <code>true</code> 302 * 303 * @see #setSecure 304 */ 305 public boolean getSecure() { 306 return secure; 307 } 308 309 /** 310 * Returns the name of the cookie. The name cannot be changed after 311 * creation. 312 * 313 * @return a <code>String</code> specifying the cookie's name 314 */ 315 public String getName() { 316 return name; 317 } 318 319 /** 320 * Assigns a new value to a cookie after the cookie is created. 321 * If you use a binary value, you may want to use BASE64 encoding. 322 * 323 * <p>With Version 0 cookies, values should not contain white 324 * space, brackets, parentheses, equals signs, commas, 325 * double quotes, slashes, question marks, at signs, colons, 326 * and semicolons. Empty values may not behave the same way 327 * on all browsers. 328 * 329 * @param newValue a <code>String</code> specifying the new value 330 * 331 * @see #getValue 332 * @see Cookie 333 */ 334 public void setValue(String newValue) { 335 value = newValue; 336 } 337 338 /** 339 * Returns the value of the cookie. 340 * 341 * @return a <code>String</code> containing the cookie's 342 * present value 343 * 344 * @see #setValue 345 * @see Cookie 346 */ 347 public String getValue() { 348 return value; 349 } 350 351 /** 352 * Returns the version of the protocol this cookie complies 353 * with. Version 1 complies with RFC 2109, 354 * and version 0 complies with the original 355 * cookie specification drafted by Netscape. Cookies provided 356 * by a browser use and identify the browser's cookie version. 357 * 358 * @return 0 if the cookie complies with the original Netscape 359 * specification; 1 if the cookie complies with RFC 2109 360 * 361 * @see #setVersion 362 */ 363 public int getVersion() { 364 return version; 365 } 366 367 /** 368 * Sets the version of the cookie protocol this cookie complies 369 * with. Version 0 complies with the original Netscape cookie 370 * specification. Version 1 complies with RFC 2109. 371 * 372 * <p>Since RFC 2109 is still somewhat new, consider 373 * version 1 as experimental; do not use it yet on production sites. 374 * 375 * @param v 0 if the cookie should comply with the original Netscape 376 * specification; 1 if the cookie should comply with RFC 2109 377 * 378 * @see #getVersion 379 */ 380 public void setVersion(int v) { 381 version = v; 382 } 383 384 // Note -- disabled for now to allow full Netscape compatibility 385 // from RFC 2068, token special case characters 386 // 387 // private static final String tspecials = "()<>@,;:\\\"/[]?={} \t"; 388 389 private static final String tspecials = ",; "; 390 391 /** 392 * Tests a string and returns true if the string counts as a 393 * reserved token in the Java language. 394 * 395 * @param value the <code>String</code> to be tested 396 * 397 * @return <code>true</code> if the <code>String</code> is 398 * a reserved token; <code>false</code> if it is not 399 */ 400 private boolean isToken(String value) { 401 int len = value.length(); 402 403 for (int i = 0; i < len; i++) { 404 char c = value.charAt(i); 405 406 if (c < 0x20 || c >= 0x7f || tspecials.indexOf(c) != -1) 407 return false; 408 } 409 return true; 410 } 411 412 /** 413 * Overrides the standard <code>java.lang.Object.clone</code> 414 * method to return a copy of this cookie. 415 */ 416 public Object clone() { 417 try { 418 return super.clone(); 419 } catch (CloneNotSupportedException e) { 420 throw new RuntimeException(e.getMessage()); 421 } 422 } 423 } 424