javax.servlet.http
public class Cookie extends Object implements Cloneable
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.
The servlet sends cookies to the browser by using the HttpServletResponse method, which adds fields to HTTP response headers to send cookies to the browser, one at a time. The browser is expected to support 20 cookies for each Web server, 300 cookies total, and may limit cookie size to 4 KB each.
The browser returns cookies to the servlet by adding fields to HTTP request headers. Cookies can be retrieved from a request by using the HttpServletRequest method. Several cookies might have the same name but different path attributes.
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.
This class supports both the Version 0 (by Netscape) and Version 1 (by RFC 2109) cookie specifications. By default, cookies are created using Version 0 to ensure the best interoperability.
Version: $Version$
| Constructor Summary | |
|---|---|
| Cookie(String name, String value)
Constructs a cookie with a specified name and value.
| |
| Method Summary | |
|---|---|
| Object | clone()
Overrides the standard java.lang.Object.clone
method to return a copy of this cookie.
|
| String | getComment()
Returns the comment describing the purpose of this cookie, or
null if the cookie has no comment.
|
| String | getDomain()
Returns the domain name set for this cookie. |
| int | getMaxAge()
Returns the maximum age of the cookie, specified in seconds,
By default, -1 indicating the cookie will persist
until browser shutdown.
|
| String | getName()
Returns the name of the cookie. |
| String | getPath()
Returns the path on the server
to which the browser returns this cookie. |
| boolean | getSecure()
Returns true if the browser is sending cookies
only over a secure protocol, or false if the
browser can send cookies using any protocol.
|
| String | getValue()
Returns the value of the cookie.
|
| int | getVersion()
Returns the version of the protocol this cookie complies
with. |
| void | setComment(String purpose)
Specifies a comment that describes a cookie's purpose.
|
| void | setDomain(String pattern)
Specifies the domain within which this cookie should be presented.
|
| void | setMaxAge(int expiry)
Sets the maximum age of the cookie in seconds.
|
| void | setPath(String uri)
Specifies a path for the cookie
to which the client should return the cookie.
|
| void | setSecure(boolean flag)
Indicates to the browser whether the cookie should only be sent
using a secure protocol, such as HTTPS or SSL.
|
| void | setValue(String newValue)
Assigns a new value to a cookie after the cookie is created.
|
| void | setVersion(int v)
Sets the version of the cookie protocol this cookie complies
with. |
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.
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
setValue method.
By default, cookies are created according to the Netscape
cookie specification. The version can be changed with the
setVersion method.
Parameters: name a String specifying the name of the cookie
value a String 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
java.lang.Object.clone
method to return a copy of this cookie.
null if the cookie has no comment.
Returns: a String containing the comment,
or null if none
See Also: Cookie
Returns: a String containing the domain name
See Also: Cookie
-1 indicating the cookie will persist
until browser shutdown.
Returns: an integer specifying the maximum age of the cookie in seconds; if negative, means the cookie persists until browser shutdown
See Also: Cookie
Returns: a String specifying the cookie's name
Returns: a String specifying a path that contains
a servlet name, for example, /catalog
See Also: Cookie
true if the browser is sending cookies
only over a secure protocol, or false if the
browser can send cookies using any protocol.
Returns: true if the browser uses a secure protocol;
otherwise, true
See Also: Cookie
Returns: a String containing the cookie's
present value
See Also: Cookie
Returns: 0 if the cookie complies with the original Netscape specification; 1 if the cookie complies with RFC 2109
See Also: Cookie
Parameters: purpose a String specifying the comment
to display to the user
See Also: Cookie
The form of the domain name is specified by RFC 2109. A domain
name begins with a dot (.foo.com) and means that
the cookie is visible to servers in a specified Domain Name System
(DNS) zone (for example, www.foo.com, but not
a.b.foo.com). By default, cookies are only returned
to the server that sent them.
Parameters: pattern a String containing the domain name
within which this cookie is visible;
form is according to RFC 2109
See Also: Cookie
A positive value indicates that the cookie will expire after that many seconds have passed. Note that the value is the maximum age when the cookie will expire, not the cookie's current age.
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.
Parameters: 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 Also: Cookie
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, /catalog, which makes the cookie visible to all directories on the server under /catalog.
Consult RFC 2109 (available on the Internet) for more information on setting path names for cookies.
Parameters: uri a String specifying a path
See Also: Cookie
The default value is false.
Parameters: flag if true, sends the cookie from the browser
to the server only when using a secure protocol;
if false, sent on any protocol
See Also: Cookie
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.
Parameters: newValue a String specifying the new value
See Also: Cookie
Since RFC 2109 is still somewhat new, consider version 1 as experimental; do not use it yet on production sites.
Parameters: v 0 if the cookie should comply with the original Netscape specification; 1 if the cookie should comply with RFC 2109
See Also: Cookie