Cookie.java
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package javax.servlet.http;
import java.io.Serializable;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.text.MessageFormat;
import java.util.BitSet;
import java.util.Locale;
import java.util.ResourceBundle;
/**
* Creates a cookie, a small amount of information sent by a servlet to a Web browser, saved by the browser, and later
* sent back to the server. A cookie's value can uniquely identify a client, so cookies are commonly used for session
* management.
* <p>
* A cookie has a name, a single value, and optional attributes such as a comment, path and domain qualifiers, a maximum
* age, and a version number. Some Web browsers have bugs in how they handle the optional attributes, so use them
* sparingly to improve the interoperability of your servlets.
* <p>
* The servlet sends cookies to the browser by using the {@link HttpServletResponse#addCookie} method, which adds fields
* to HTTP response headers to send cookies to the browser, one at a time. The browser is expected to support 50 cookies
* for each domain, 3000 cookies total, and may limit cookie size to 4 KiB each.
* <p>
* The browser returns cookies to the servlet by adding fields to HTTP request headers. Cookies can be retrieved from a
* request by using the {@link HttpServletRequest#getCookies} method. Several cookies might have the same name but
* different path attributes.
* <p>
* Cookies affect the caching of the Web pages that use them. HTTP 1.0 does not cache pages that use cookies created
* with this class. This class does not support the cache control defined with HTTP 1.1.
* <p>
* This class supports both the RFC 2109 and the RFC 6265 specifications. By default, cookies are created using RFC
* 6265.
*/
public class Cookie implements Cloneable, Serializable {
private static final CookieNameValidator validation;
static {
boolean strictServletCompliance;
boolean strictNaming;
boolean allowSlash;
String propStrictNaming;
String propFwdSlashIsSeparator;
if (System.getSecurityManager() == null) {
strictServletCompliance = Boolean.getBoolean("org.apache.catalina.STRICT_SERVLET_COMPLIANCE");
propStrictNaming = System.getProperty("org.apache.tomcat.util.http.ServerCookie.STRICT_NAMING");
propFwdSlashIsSeparator =
System.getProperty("org.apache.tomcat.util.http.ServerCookie.FWD_SLASH_IS_SEPARATOR");
} else {
strictServletCompliance = AccessController
.doPrivileged((PrivilegedAction<Boolean>) () -> Boolean
.valueOf(System.getProperty("org.apache.catalina.STRICT_SERVLET_COMPLIANCE")))
.booleanValue();
propStrictNaming = AccessController.doPrivileged((PrivilegedAction<String>) () -> System
.getProperty("org.apache.tomcat.util.http.ServerCookie.STRICT_NAMING"));
propFwdSlashIsSeparator = AccessController.doPrivileged((PrivilegedAction<String>) () -> System
.getProperty("org.apache.tomcat.util.http.ServerCookie.FWD_SLASH_IS_SEPARATOR"));
}
if (propStrictNaming == null) {
strictNaming = strictServletCompliance;
} else {
strictNaming = Boolean.parseBoolean(propStrictNaming);
}
if (propFwdSlashIsSeparator == null) {
allowSlash = !strictServletCompliance;
} else {
allowSlash = !Boolean.parseBoolean(propFwdSlashIsSeparator);
}
if (strictNaming) {
validation = new RFC2109Validator(allowSlash);
} else {
validation = new RFC6265Validator();
}
}
private static final long serialVersionUID = 1L;
/**
* Cookie name.
*/
private final String name;
/**
* Cookie value.
*/
private String value;
/**
* Cookie version value. {@code ;Version=1 ...} means RFC 2109 style.
*/
private int version = 0;
//
// Attributes encoded in the header's cookie fields.
//
/**
* {@code ;Comment=VALUE ...} describes cookie's use.
*/
private String comment;
/**
* {@code ;Domain=VALUE ...} domain that sees cookie
*/
private String domain;
/**
* {@code ;Max-Age=VALUE ...} cookies auto-expire
*/
private int maxAge = -1;
/**
* {@code ;Path=VALUE ...} URLs that see the cookie
*/
private String path;
/**
* {@code ;Secure ...} e.g. use SSL
*/
private boolean secure;
/**
* Not in cookie specs, but supported by browsers.
*/
private boolean httpOnly;
/**
* Constructs a cookie with a specified name and value.
* <p>
* The name must conform to RFC 2109. That means it can contain only ASCII alphanumeric characters and cannot
* contain commas, semicolons, or white space or begin with a $ character. The cookie's name cannot be changed after
* creation.
* <p>
* The value can be anything the server chooses to send. Its value is probably of interest only to the server. The
* cookie's value can be changed after creation with the <code>setValue</code> method.
* <p>
* By default, cookies are created according to the Netscape cookie specification. The version can be changed with
* the <code>setVersion</code> method.
*
* @param name a <code>String</code> specifying the name of the cookie
* @param value a <code>String</code> specifying the value of the cookie
*
* @throws IllegalArgumentException if the cookie name contains illegal characters (for example, a comma, space, or
* semicolon) or it is one of the tokens reserved for use by the cookie
* protocol
*
* @see #setValue
* @see #setVersion
*/
public Cookie(String name, String value) {
validation.validate(name);
this.name = name;
this.value = value;
}
/**
* Specifies a comment that describes a cookie's purpose. The comment is useful if the browser presents the cookie
* to the user. Comments are not supported by Netscape Version 0 cookies.
*
* @param purpose a <code>String</code> specifying the comment to display to the user
*
* @see #getComment
*/
public void setComment(String purpose) {
comment = purpose;
}
/**
* Returns the comment describing the purpose of this cookie, or <code>null</code> if the cookie has no comment.
*
* @return a <code>String</code> containing the comment, or <code>null</code> if none
*
* @see #setComment
*/
public String getComment() {
return comment;
}
/**
* Specifies the domain within which this cookie should be presented.
* <p>
* The form of the domain name is specified by RFC 2109. A domain name begins with a dot (<code>.foo.com</code>) and
* means that the cookie is visible to servers in a specified Domain Name System (DNS) zone (for example,
* <code>www.foo.com</code>, but not <code>a.b.foo.com</code>). By default, cookies are only returned to the server
* that sent them.
*
* @param pattern a <code>String</code> containing the domain name within which this cookie is visible; form is
* according to RFC 2109
*
* @see #getDomain
*/
public void setDomain(String pattern) {
domain = pattern.toLowerCase(Locale.ENGLISH); // IE allegedly needs this
}
/**
* Returns the domain name set for this cookie. The form of the domain name is set by RFC 2109.
*
* @return a <code>String</code> containing the domain name
*
* @see #setDomain
*/
public String getDomain() {
return domain;
}
/**
* Sets the maximum age of the cookie in seconds.
* <p>
* A positive value indicates that the cookie will expire after that many seconds have passed. Note that the value
* is the <i>maximum</i> age when the cookie will expire, not the cookie's current age.
* <p>
* A negative value means that the cookie is not stored persistently and will be deleted when the Web browser exits.
* A zero value causes the cookie to be deleted.
*
* @param expiry an integer specifying the maximum age of the cookie in seconds; if negative, means the cookie is
* not stored; if zero, deletes the cookie
*
* @see #getMaxAge
*/
public void setMaxAge(int expiry) {
maxAge = expiry;
}
/**
* Returns the maximum age of the cookie, specified in seconds, By default, <code>-1</code> indicating the cookie
* will persist until browser shutdown.
*
* @return an integer specifying the maximum age of the cookie in seconds; if negative, means the cookie persists
* until browser shutdown
*
* @see #setMaxAge
*/
public int getMaxAge() {
return maxAge;
}
/**
* Specifies a path for the cookie to which the client should return the cookie.
* <p>
* The cookie is visible to all the pages in the directory you specify, and all the pages in that directory's
* subdirectories. A cookie's path must include the servlet that set the cookie, for example, <i>/catalog</i>, which
* makes the cookie visible to all directories on the server under <i>/catalog</i>.
* <p>
* Consult RFC 2109 (available on the Internet) for more information on setting path names for cookies.
*
* @param uri a <code>String</code> specifying a path
*
* @see #getPath
*/
public void setPath(String uri) {
path = uri;
}
/**
* Returns the path on the server to which the browser returns this cookie. The cookie is visible to all subpaths on
* the server.
*
* @return a <code>String</code> specifying a path that contains a servlet name, for example, <i>/catalog</i>
*
* @see #setPath
*/
public String getPath() {
return path;
}
/**
* Indicates to the browser whether the cookie should only be sent using a secure protocol, such as HTTPS or SSL.
* <p>
* The default value is <code>false</code>.
*
* @param flag if <code>true</code>, sends the cookie from the browser to the server only when using a secure
* protocol; if <code>false</code>, sent on any protocol
*
* @see #getSecure
*/
public void setSecure(boolean flag) {
secure = flag;
}
/**
* Returns <code>true</code> if the browser is sending cookies only over a secure protocol, or <code>false</code> if
* the browser can send cookies using any protocol.
*
* @return <code>true</code> if the browser uses a secure protocol; otherwise, <code>false</code>
*
* @see #setSecure
*/
public boolean getSecure() {
return secure;
}
/**
* Returns the name of the cookie. The name cannot be changed after creation.
*
* @return a <code>String</code> specifying the cookie's name
*/
public String getName() {
return name;
}
/**
* Assigns a new value to a cookie after the cookie is created. If you use a binary value, you may want to use
* BASE64 encoding.
* <p>
* With Version 0 cookies, values should not contain white space, brackets, parentheses, equals signs, commas,
* double quotes, slashes, question marks, at signs, colons, and semicolons. Empty values may not behave the same
* way on all browsers.
*
* @param newValue a <code>String</code> specifying the new value
*
* @see #getValue
* @see Cookie
*/
public void setValue(String newValue) {
value = newValue;
}
/**
* Returns the value of the cookie.
*
* @return a <code>String</code> containing the cookie's present value
*
* @see #setValue
* @see Cookie
*/
public String getValue() {
return value;
}
/**
* Returns the version of the protocol this cookie complies with. Version 1 complies with RFC 2109, and version 0
* complies with the original cookie specification drafted by Netscape. Cookies provided by a browser use and
* identify the browser's cookie version.
*
* @return 0 if the cookie complies with the original Netscape specification; 1 if the cookie complies with RFC 2109
*
* @see #setVersion
*/
public int getVersion() {
return version;
}
/**
* Sets the version of the cookie protocol this cookie complies with. Version 0 complies with the original Netscape
* cookie specification. Version 1 complies with RFC 2109.
* <p>
* Since RFC 2109 is still somewhat new, consider version 1 as experimental; do not use it yet on production sites.
*
* @param v 0 if the cookie should comply with the original Netscape specification; 1 if the cookie should comply
* with RFC 2109
*
* @see #getVersion
*/
public void setVersion(int v) {
version = v;
}
/**
* Overrides the standard <code>java.lang.Object.clone</code> method to return a copy of this cookie.
*/
@Override
public Object clone() {
try {
return super.clone();
} catch (CloneNotSupportedException e) {
throw new RuntimeException(e);
}
}
/**
* Sets the flag that controls if this cookie will be hidden from scripts on the client side.
*
* @param httpOnly The new value of the flag
*
* @since Servlet 3.0
*/
public void setHttpOnly(boolean httpOnly) {
this.httpOnly = httpOnly;
}
/**
* Gets the flag that controls if this cookie will be hidden from scripts on the client side.
*
* @return <code>true</code> if the cookie is hidden from scripts, else <code>false</code>
*
* @since Servlet 3.0
*/
public boolean isHttpOnly() {
return httpOnly;
}
}
class CookieNameValidator {
private static final String LSTRING_FILE = "javax.servlet.http.LocalStrings";
protected static final ResourceBundle lStrings = ResourceBundle.getBundle(LSTRING_FILE);
protected final BitSet allowed;
protected CookieNameValidator(String separators) {
allowed = new BitSet(128);
allowed.set(0x20, 0x7f); // any CHAR except CTLs or separators
for (int i = 0; i < separators.length(); i++) {
char ch = separators.charAt(i);
allowed.clear(ch);
}
}
void validate(String name) {
if (name == null || name.length() == 0) {
throw new IllegalArgumentException(lStrings.getString("err.cookie_name_blank"));
}
if (!isToken(name)) {
String errMsg = lStrings.getString("err.cookie_name_is_token");
throw new IllegalArgumentException(MessageFormat.format(errMsg, name));
}
}
private boolean isToken(String possibleToken) {
int len = possibleToken.length();
for (int i = 0; i < len; i++) {
char c = possibleToken.charAt(i);
if (!allowed.get(c)) {
return false;
}
}
return true;
}
}
class RFC6265Validator extends CookieNameValidator {
private static final String RFC2616_SEPARATORS = "()<>@,;:\\\"/[]?={} \t";
RFC6265Validator() {
super(RFC2616_SEPARATORS);
}
}
class RFC2109Validator extends RFC6265Validator {
RFC2109Validator(boolean allowSlash) {
// special treatment to allow for FWD_SLASH_IS_SEPARATOR property
if (allowSlash) {
allowed.set('/');
}
}
@Override
void validate(String name) {
super.validate(name);
if (name.charAt(0) == '$') {
String errMsg = lStrings.getString("err.cookie_name_is_token");
throw new IllegalArgumentException(MessageFormat.format(errMsg, name));
}
}
}