This document discusses the Servlet API and javax.servlet.http package for building servlets in Java. It explains that these contain classes and interfaces required for servlets, including lifecycle methods like init(), service(), and destroy(). It also describes the HttpServletRequest and HttpServletResponse classes for getting request information and sending HTTP responses from servlets.

1. Advanced java programming
Servlet API & Servlet Http package
By
P.Abinaya

3.  Two packages contain the classes and
interfaces that are required to build
servlets.
 Then are javax.servlet and
javax.servlet.http.
 The Servelt API has been in a process of
ongoing development and enhancement.
 The current servlet specification is version
2.4.

5.  The javax.servlet.http package
contains a number of classes and
interfaces that describe and define the
contracts between a servlet class
running under the HTTP protocol and
the runtime environment provided for
an instance of such a class by a
conforming servlet container.

6.  init()
 Service()
 Destroy()
 That methods are the life cycle methods of
servlet.
 The getServletConfig() method is called by
the servlet to obtain initialization
parameter.

7. HttpServletRequest
Extends the ServletRequest interface
to provide request information for
HTTP servlets.
HttpServletResponse
Extends the ServletResponse interface
to provide HTTP-specific functionality
in sending a response.

8. The javax.servlet.http package
contains a number of interfaces
and classes that are commonly
used by servlet developers.
That its functionality makes it
easy to build servlets that work
with HTTP requests and
responses.

9.  The HttpServletRequest Interface
 Extends the ServletRequest interface to
provide request information for HTTP
servlets.
 The HttpServletRequest Interface
Extends the ServletResponse interface to
provide HTTP-specific functionality in
sending a response.

10.  The Cookie class encapsulates a cookie.
 A cookie is stored on a client and contains
state information.
 Some of the information that is saved for
each cookie includes the following:
o The name of the cookie.
o The value of the cookie.
o The expiration date of the cookie.
o The domain and path of the cookie.

11.  The HttpServlet class provides specialized
methods that handle the various types of
HTTP requests.
 The methods are
 doDelet()
 DoGet()
 doHead()
 doOptions()
 doPut()
 doTrace().