| java.lang.Object
 javax.servlet.http.Cookie
| Cookie | | public class Cookie implements Cloneable(Code) | | 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.
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.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 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.getCookies 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.
author:
Various
version:
$Version$ |
| Constructor Summary | |
| public | Cookie(String name, String value)
Constructs a cookie with a specified name and value.
The name must conform to RFC 2109. |
| Method Summary | |
| public Object | clone()
Overrides the standard java.lang.Object.clone
method to return a copy of this cookie. | | public String | getComment()
Returns the comment describing the purpose of this cookie, or
null if the cookie has no comment. | | public String | getDomain()
Returns the domain name set for this cookie. | | public int | getMaxAge()
Returns the maximum age of the cookie, specified in seconds,
By default, -1 indicating the cookie will persist
until browser shutdown. | | public String | getName()
Returns the name of the cookie. | | public String | getPath()
Returns the path on the server
to which the browser returns this cookie. | | public 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. | | public String | getValue()
Returns the value of the cookie. | | public int | getVersion()
Returns the version of the protocol this cookie complies
with. | | public void | setComment(String purpose)
Specifies a comment that describes a cookie's purpose.
The comment is useful if the browser presents the cookie
to the user. | | public void | setDomain(String pattern)
Specifies the domain within which this cookie should be presented.
The form of the domain name is specified by RFC 2109. | | public void | setMaxAge(int expiry)
Sets the maximum age of the cookie in seconds.
A positive value indicates that the cookie will expire
after that many seconds have passed. | | public void | setPath(String uri)
Specifies a path for the cookie
to which the client should return the cookie.
The cookie is visible to all the pages in the directory
you specify, and all the pages in that directory's subdirectories. | | public void | setSecure(boolean flag)
Indicates to the browser whether the cookie should only be sent
using a secure protocol, such as HTTPS or SSL. | | public void | setValue(String newValue)
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.
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. | | public void | setVersion(int v)
Sets the version of the cookie protocol this cookie complies
with. |
| Cookie | | public Cookie(String name, String value)(Code) | | Constructs a cookie with a specified name and value.
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
Parameters:
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 useby the cookie protocol
See Also: Cookie.setValue
See Also: Cookie.setVersion |
| clone | | public Object clone()(Code) | | Overrides the standard java.lang.Object.clone
method to return a copy of this cookie.
|
| getComment | | public String getComment()(Code) | | Returns the comment describing the purpose of this cookie, or
null if the cookie has no comment.
a String containing the comment,or null if none
See Also: Cookie.setComment |
| getDomain | | public String getDomain()(Code) | | Returns the domain name set for this cookie. The form of
the domain name is set by RFC 2109.
a String containing the domain name
See Also: Cookie.setDomain |
| getMaxAge | | public int getMaxAge()(Code) | | Returns the maximum age of the cookie, specified in seconds,
By default, -1 indicating the cookie will persist
until browser shutdown.
an integer specifying the maximum age of thecookie in seconds; if negative, meansthe cookie persists until browser shutdown
See Also: Cookie.setMaxAge |
| getName | | public String getName()(Code) | | Returns the name of the cookie. The name cannot be changed after
creation.
a String specifying the cookie's name |
| getPath | | public String getPath()(Code) | | Returns the path on the server
to which the browser returns this cookie. The
cookie is visible to all subpaths on the server.
a String specifying a path that containsa servlet name, for example, /catalog
See Also: Cookie.setPath |
| getSecure | | public boolean getSecure()(Code) | | Returns true if the browser is sending cookies
only over a secure protocol, or false if the
browser can send cookies using any protocol.
true if the browser uses a secure protocol;otherwise, true
See Also: Cookie.setSecure |
| getVersion | | public int getVersion()(Code) | | 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.
0 if the cookie complies with theoriginal Netscape specification; 1if the cookie complies with RFC 2109
See Also: Cookie.setVersion |
| setComment | | public void setComment(String purpose)(Code) | | 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.
Parameters:
purpose - a String specifying the comment to display to the user
See Also: Cookie.getComment |
| setDomain | | public void setDomain(String pattern)(Code) | | Specifies the domain within which this cookie should be presented.
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 namewithin which this cookie is visible;form is according to RFC 2109
See Also: Cookie.getDomain |
| setMaxAge | | public void setMaxAge(int expiry)(Code) | | Sets the maximum age of the cookie in seconds.
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 thecookie in seconds; if negative, meansthe cookie is not stored; if zero, deletesthe cookie
See Also: Cookie.getMaxAge |
| setPath | | public void setPath(String uri)(Code) | | Specifies a path for the cookie
to which the client should return the 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.getPath |
| setSecure | | public void setSecure(boolean flag)(Code) | | Indicates to the browser whether the cookie should only be sent
using a secure protocol, such as HTTPS or SSL.
The default value is false.
Parameters:
flag - if true, sends the cookie from the browserto the server only when using a secure protocol;if false, sent on any protocol
See Also: Cookie.getSecure |
| setValue | | public void setValue(String newValue)(Code) | | 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.
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.getValue
See Also: Cookie |
| setVersion | | public void setVersion(int v)(Code) | | 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.
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.getVersion |
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