Java Servlet Programming

Name

Cookie

Synopsis

Class Name: javax.servlet.http.Cookie

Superclass: java.lang.Object

Immediate Subclasses: None

Interfaces Implemented: java.lang.Cloneable

Availability: New as of Servlet API 2.0; found in JSDK 2.0, JWS 1.1; an earlier version previously in sun.* hierarchy

Description

The Cookie class provides an easy way for servlets to read, create, and manipulate HTTP-style cookies, which allow servlets to store small amounts of data on the client. Cookies are generally used for session tracking or storing small amounts of user-specific configuration information. For more information, consult Chapter 7.

A servlet uses the getCookies() method of HttpServletRequest to retrieve cookies submitted as part of a client request. The addCookie() method of HttpServletResponse sends a new cookie to the browser. Because cookies are set using HTTP headers, addCookie() must be called before any output is sent to the client.

The original Servlet API 1.0 lacked this Cookie class, although the Java Web Server included a Sun-specific sun.servlet.util.Cookie class that worked in roughly the same manner. The only significant difference is that the retrieval and creation methods were static components of the Cookie class itself, rather than being part of the HttpServletRequest and HttpServletResponse interfaces.

Class Summary

public class Cookie implements java.lang.Cloneable { // Constructors public Cookie(String name, String value); // Instance Methods public Object clone(); public String getComment(); ...