javax.servlet.http.Cookie Maven / Gradle / Ivy
/*
* JBoss, Home of Professional Open Source.
* Copyright 2007, Red Hat Middleware LLC, and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package javax.servlet.http;
import java.text.MessageFormat;
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.
*
* 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
* {@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 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
* {@link 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
*/
// XXX would implement java.io.Serializable too, but can't do that
// so long as sun.servlet.* must run on older JDK 1.02 JVMs which
// don't include that support.
public class Cookie implements Cloneable
{
private static final String LSTRING_FILE = "javax.servlet.http.LocalStrings";
private static ResourceBundle lStrings = ResourceBundle.getBundle(LSTRING_FILE);
//
// The value of the cookie itself.
//
private String name; // NAME= ... "$Name" style is reserved
private String value; // value of NAME
//
// Attributes encoded in the header's cookie fields.
//
private String comment; // ;Comment=VALUE ... describes cookie's use
// ;Discard ... implied by maxAge < 0
private String domain; // ;Domain=VALUE ... domain that sees cookie
private int maxAge = -1; // ;Max-Age=VALUE ... cookies auto-expire
private String path; // ;Path=VALUE ... URLs that see the cookie
private boolean secure; // ;Secure ... e.g. use SSL
private int version = 0; // ;Version=1 ... means RFC 2109++ style
/**
* 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.
*
* @param name
* a String specifying the name of the cookie
* @param 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
* @see #setValue
* @see #setVersion
*/
public Cookie(String name, String value)
{
if (!isToken(name) || name.equalsIgnoreCase("Comment") // rfc2019
|| name.equalsIgnoreCase("Discard") // 2019++
|| name.equalsIgnoreCase("Domain") || name.equalsIgnoreCase("Expires") // (old
// cookies)
|| name.equalsIgnoreCase("Max-Age") // rfc2019
|| name.equalsIgnoreCase("Path") || name.equalsIgnoreCase("Secure") || name.equalsIgnoreCase("Version") || name.startsWith("$"))
{
String errMsg = lStrings.getString("err.cookie_name_is_token");
Object[] errArgs = new Object[1];
errArgs[0] = name;
errMsg = MessageFormat.format(errMsg, errArgs);
throw new IllegalArgumentException(errMsg);
}
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 String 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
* null if the cookie has no comment.
*
* @return a String containing the comment, or
* null if none
* @see #setComment
*/
public String getComment()
{
return comment;
}
/**
* 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.
*
* @param pattern
* a String 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(); // 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 String containing the domain name
* @see #setDomain
*/
public String getDomain()
{
return domain;
}
/**
* 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.
*
* @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,
* -1 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.
*
* 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.
*
* @param uri
* a String 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 String specifying a path that contains a servlet
* name, for example, /catalog
* @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.
*
* The default value is false.
*
* @param 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 #getSecure
*/
public void setSecure(boolean flag)
{
secure = flag;
}
/**
* Returns true if the browser is sending cookies only over a
* secure protocol, or false if the browser can send cookies
* using any protocol.
*
* @return true if the browser uses a secure protocol;
* otherwise, true
* @see #setSecure
*/
public boolean getSecure()
{
return secure;
}
/**
* Returns the name of the cookie. The name cannot be changed after creation.
*
* @return a String 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.
*
* 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 String specifying the new value
* @see #getValue
* @see Cookie
*/
public void setValue(String newValue)
{
value = newValue;
}
/**
* Returns the value of the cookie.
*
* @return a String 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.
*
* 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;
}
// Note -- disabled for now to allow full Netscape compatibility
// from RFC 2068, token special case characters
//
// private static final String tspecials = "()<>@,;:\\\"/[]?={} \t";
private static final String tspecials = ",; ";
/*
* Tests a string and returns true if the string counts as a reserved token
* in the Java language. @param value the String to be tested
* @return true if the String is a reserved
* token; false if it is not
*/
private boolean isToken(String value)
{
int len = value.length();
for (int i = 0; i < len; i++)
{
char c = value.charAt(i);
if (c < 0x20 || c >= 0x7f || tspecials.indexOf(c) != -1)
return false;
}
return true;
}
/**
* Overrides the standard java.lang.Object.clone method to
* return a copy of this cookie.
*/
public Object clone()
{
try
{
return super.clone();
}
catch (CloneNotSupportedException e)
{
throw new RuntimeException(e.getMessage());
}
}
}