HttpCookie

public final class HttpCookie extends Object
implements Cloneable

An HttpCookie object represents an HTTP cookie, which carries state information between server and user agent. Cookie is widely adopted to create stateful sessions.

There are 3 HTTP cookie specifications:

Netscape draft
RFC 2109 - http://www.ietf.org/rfc/rfc2109.txt
RFC 2965 - http://www.ietf.org/rfc/rfc2965.txt

HttpCookie class can accept all these 3 forms of syntax.

Public Constructor Summary

HttpCookie(String name, String value)
Constructs a cookie with a specified name and value.

Public Method Summary

Object
clone()
Create and return a copy of this object.
static boolean
domainMatches(String domain, String host)
The utility method to check whether a host name is in a domain or not.
boolean
equals(Object obj)
Test the equality of two HTTP cookies.
String
getComment()
Returns the comment describing the purpose of this cookie, or null if the cookie has no comment.
String
getCommentURL()
Returns the comment URL describing the purpose of this cookie, or null if the cookie has no comment URL.
boolean
getDiscard()
Returns the discard attribute of the cookie
String
getDomain()
Returns the domain name set for this cookie.
long
getMaxAge()
Returns the maximum age of the cookie, specified in seconds.
String
getName()
Returns the name of the cookie.
String
getPath()
Returns the path on the server to which the browser returns this cookie.
String
getPortlist()
Returns the port list attribute of the cookie
boolean
getSecure()
Returns true if sending this cookie should be restricted to a secure protocol, or false if the it can be sent using any protocol.
String
getValue()
Returns the value of the cookie.
int
getVersion()
Returns the version of the protocol this cookie complies with.
boolean
hasExpired()
Reports whether this HTTP cookie has expired or not.
int
hashCode()
Returns the hash code of this HTTP cookie.
boolean
isHttpOnly()
Returns true if this cookie contains the HttpOnly attribute.
static List<HttpCookie>
parse(String header)
Constructs cookies from set-cookie or set-cookie2 header string.
void
setComment(String purpose)
Specifies a comment that describes a cookie's purpose.
void
setCommentURL(String purpose)
Specifies a comment URL that describes a cookie's purpose.
void
setDiscard(boolean discard)
Specify whether user agent should discard the cookie unconditionally.
void
setDomain(String pattern)
Specifies the domain within which this cookie should be presented.
void
setHttpOnly(boolean httpOnly)
Indicates whether the cookie should be considered HTTP Only.
void
setMaxAge(long 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
setPortlist(String ports)
Specify the portlist of the cookie, which restricts the port(s) to which a cookie may be sent back in a Cookie header.
void
setSecure(boolean flag)
Indicates 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.
String
toString()
Constructs a cookie header string representation of this cookie, which is in the format defined by corresponding cookie specification, but without the leading "Cookie:" token.

Inherited Method Summary

Public Constructors

public HttpCookie (String name, String value)

Constructs a cookie with a specified name and value.

The name must conform to RFC 2965. 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 RFC 2965 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
NullPointerException if name is null

Public Methods

public Object clone ()

Create and return a copy of this object.

Returns
  • a clone of this HTTP cookie

public static boolean domainMatches (String domain, String host)

The utility method to check whether a host name is in a domain or not.

This concept is described in the cookie specification. To understand the concept, some terminologies need to be defined first:

effective host name = hostname if host name contains dot
                  or = hostname.local if not

Host A's name domain-matches host B's if:

  • their host name strings string-compare equal; or
  • A is a HDN string and has the form NB, where N is a non-empty name string, B has the form .B', and B' is a HDN string. (So, x.y.com domain-matches .Y.com but not Y.com.)

A host isn't in a domain (RFC 2965 sec. 3.3.2) if:

  • The value for the Domain attribute contains no embedded dots, and the value is not .local.
  • The effective host name that derives from the request-host does not domain-match the Domain attribute.
  • The request-host is a HDN (not IP address) and has the form HD, where D is the value of the Domain attribute, and H is a string that contains one or more dots.

Examples:

  • A Set-Cookie2 from request-host y.x.foo.com for Domain=.foo.com would be rejected, because H is y.x and contains a dot.
  • A Set-Cookie2 from request-host x.foo.com for Domain=.foo.com would be accepted.
  • A Set-Cookie2 with Domain=.com or Domain=.com., will always be rejected, because there is no embedded dot.
  • A Set-Cookie2 from request-host example for Domain=.local will be accepted, because the effective host name for the request- host is example.local, and example.local domain-matches .local.

Parameters
domain the domain name to check host name with
host the host name in question
Returns
  • true if they domain-matches; false if not

public boolean equals (Object obj)

Test the equality of two HTTP cookies.

The result is true only if two cookies come from same domain (case-insensitive), have same name (case-insensitive), and have same path (case-sensitive).

Parameters
obj the object to compare this instance with.
Returns
  • true if two HTTP cookies equal to each other; otherwise, false

public String getComment ()

Returns the comment describing the purpose of this cookie, or null if the cookie has no comment.

Returns
  • a String containing the comment, or null if none

public String getCommentURL ()

Returns the comment URL describing the purpose of this cookie, or null if the cookie has no comment URL.

Returns
  • a String containing the comment URL, or null if none

public boolean getDiscard ()

Returns the discard attribute of the cookie

Returns
  • a boolean to represent this cookie's discard attribute

public String getDomain ()

Returns the domain name set for this cookie. The form of the domain name is set by RFC 2965.

Returns
  • a String containing the domain name

public long getMaxAge ()

Returns the maximum age of the cookie, specified in seconds. By default, -1 indicating the cookie will persist until browser shutdown.

Returns
  • an integer specifying the maximum age of the cookie in seconds
See Also

public String getName ()

Returns the name of the cookie. The name cannot be changed after creation.

Returns
  • a String specifying the cookie's name

public String getPath ()

Returns the path on the server to which the browser returns this cookie. The cookie is visible to all subpaths on the server.

Returns
  • a String specifying a path that contains a servlet name, for example, /catalog
See Also

public String getPortlist ()

Returns the port list attribute of the cookie

Returns
  • a String contains the port list or null if none

public boolean getSecure ()

Returns true if sending this cookie should be restricted to a secure protocol, or false if the it can be sent using any protocol.

Returns
  • false if the cookie can be sent over any standard protocol; otherwise, true

public String getValue ()

Returns the value of the cookie.

Returns
  • a String containing the cookie's present value
See Also

public int getVersion ()

Returns the version of the protocol this cookie complies with. Version 1 complies with RFC 2965/2109, 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.

Returns
  • 0 if the cookie complies with the original Netscape specification; 1 if the cookie complies with RFC 2965/2109
See Also

public boolean hasExpired ()

Reports whether this HTTP cookie has expired or not.

Returns
  • true to indicate this HTTP cookie has expired; otherwise, false

public int hashCode ()

Returns the hash code of this HTTP cookie. The result is the sum of hash code value of three significant components of this cookie: name, domain, and path. That is, the hash code is the value of the expression:

getName().toLowerCase().hashCode()
+ getDomain().toLowerCase().hashCode()
+ getPath().hashCode()

Returns
  • this HTTP cookie's hash code

public boolean isHttpOnly ()

Returns true if this cookie contains the HttpOnly attribute. This means that the cookie should not be accessible to scripting engines, like javascript.

Returns
  • true if this cookie should be considered HTTPOnly

public static List<HttpCookie> parse (String header)

Constructs cookies from set-cookie or set-cookie2 header string. RFC 2965 section 3.2.2 set-cookie2 syntax indicates that one header line may contain more than one cookie definitions, so this is a static utility method instead of another constructor.

Parameters
header a String specifying the set-cookie header. The header should start with "set-cookie", or "set-cookie2" token; or it should have no leading token at all.
Returns
  • a List of cookie parsed from header line string
Throws
IllegalArgumentException if header string violates the cookie specification's syntax or the cookie name contains illegal characters.
NullPointerException if the header string is null

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. Comments are not supported by Netscape Version 0 cookies.

Parameters
purpose a String specifying the comment to display to the user
See Also

public void setCommentURL (String purpose)

Specifies a comment URL that describes a cookie's purpose. The comment URL is useful if the browser presents the cookie to the user. Comment URL is RFC 2965 only.

Parameters
purpose a String specifying the comment URL to display to the user
See Also

public void setDiscard (boolean discard)

Specify whether user agent should discard the cookie unconditionally. This is RFC 2965 only attribute.

Parameters
discard true indicates to discard cookie unconditionally
See Also

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 2965. 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 2965
See Also

public void setHttpOnly (boolean httpOnly)

Indicates whether the cookie should be considered HTTP Only. If set to true it means the cookie should not be accessible to scripting engines like javascript.

Parameters
httpOnly if true make the cookie HTTP only, i.e. only visible as part of an HTTP request.
See Also

public void setMaxAge (long 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. 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 zero, the cookie should be discarded immediately; otherwise, the cookie's max age is unspecified.
See Also

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. 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 2965 (available on the Internet) for more information on setting path names for cookies.

Parameters
uri a String specifying a path
See Also

public void setPortlist (String ports)

Specify the portlist of the cookie, which restricts the port(s) to which a cookie may be sent back in a Cookie header.

Parameters
ports a String specify the port list, which is comma separated series of digits
See Also

public void setSecure (boolean flag)

Indicates 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, the cookie can only be sent over a secure protocol like HTTPS. If false, it can be sent over any protocol.
See Also

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. Empty values may not behave the same way on all browsers.

Parameters
newValue a String specifying the new value
See Also

public void setVersion (int v)

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 2965/2109.

Parameters
v 0 if the cookie should comply with the original Netscape specification; 1 if the cookie should comply with RFC 2965/2109
Throws
IllegalArgumentException if v is neither 0 nor 1
See Also

public String toString ()

Constructs a cookie header string representation of this cookie, which is in the format defined by corresponding cookie specification, but without the leading "Cookie:" token.

Returns
  • a string form of the cookie. The string has the defined format