public class Cookie
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
Several cookies might have the same name but different path attributes.
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.
Constructs a cookie with the specified name and value.
Overrides the standard
Returns the comment describing the purpose of this cookie, or
Gets the domain name of this Cookie.
Gets the maximum age in seconds of this Cookie.
Returns the name of the cookie.
Returns the path on the server to which the browser returns this cookie.
Gets the current value of this Cookie.
Returns the version of the protocol this cookie complies with.
Checks whether this Cookie has been marked as HttpOnly.
Specifies a comment that describes a cookie's purpose.
Specifies the domain within which this cookie should be presented.
Marks or unmarks this Cookie as HttpOnly.
Sets the maximum age in seconds for this Cookie.
Specifies a path for the cookie to which the client should return the cookie.
Indicates to the browser whether the cookie should only be sent using a secure protocol, such as HTTPS or SSL.
Assigns a new value to this Cookie.
Sets the version of the cookie protocol that this Cookie complies with.
|Methods inherited from class java.lang.Object|
public Cookie(java.lang.String name, java.lang.String value)
The name must conform to RFC 2109. However, vendors may provide a configuration option that allows cookie names conforming to the original Netscape Cookie Specification to be accepted.
The name of a cookie cannot be changed once the cookie has been created.
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
By default, cookies are created according to the Netscape
cookie specification. The version can be changed with the
name- the name of the cookie
value- the value of the cookie
java.lang.IllegalArgumentException- if the cookie name is null or empty or contains any illegal characters (for example, a comma, space, or semicolon) or matches a token reserved for use by the cookie protocol
public void setComment(java.lang.String purpose)
Stringspecifying the comment to display to the user
public java.lang.String getComment()
nullif the cookie has no comment.
public void setDomain(java.lang.String domain)
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.
domain- the domain name within which this cookie is visible; form is according to RFC 2109
public java.lang.String getDomain()
Domain names are formatted according to RFC 2109.
public void setMaxAge(int expiry)
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.
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
public int getMaxAge()
-1 is returned, which indicates that
the cookie will persist until browser shutdown.
public void setPath(java.lang.String uri)
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.
Stringspecifying a path
public java.lang.String getPath()
Stringspecifying a path that contains a servlet name, for example, /catalog
public void setSecure(boolean flag)
The default value is
true, sends the cookie from the browser to the server only when using a secure protocol; if
false, sent on any protocol
public boolean getSecure()
trueif the browser is sending cookies only over a secure protocol, or
falseif the browser can send cookies using any protocol.
trueif the browser uses a secure protocol,
public java.lang.String getName()
public void setValue(java.lang.String newValue)
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.
newValue- the new value of the cookie
public java.lang.String getValue()
public int getVersion()
public void setVersion(int v)
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.
v- 0 if the cookie should comply with the original Netscape specification; 1 if the cookie should comply with RFC 2109
public java.lang.Object clone()
java.lang.Object.clonemethod to return a copy of this Cookie.
public void setHttpOnly(boolean isHttpOnly)
If isHttpOnly is set to true, this cookie is marked as HttpOnly, by adding the HttpOnly attribute to it.
HttpOnly cookies are not supposed to be exposed to client-side scripting code, and may therefore help mitigate certain kinds of cross-site scripting attacks.
isHttpOnly- true if this cookie is to be marked as HttpOnly, false otherwise
public boolean isHttpOnly()