Package javax.servlet

This chapter describes the javax.servlet package.

See:
Description

Interface Summary

Filter	A filter is an object that performs filtering tasks on either the request to a resource (a servlet or static content), or on the response from a resource, or both. Filters perform filtering in the doFilter method.
FilterChain	A FilterChain is an object provided by the servlet container to the developer giving a view into the invocation chain of a filtered request for a resource.
FilterConfig	A filter configuration object used by a servlet container to pass information to a filter during initialization.
RequestDispatcher	Defines an object that receives requests from the client and sends them to any resource (such as a servlet, HTML file, or JSP file) on the server.
Servlet	Defines methods that all servlets must implement.
ServletConfig	A servlet configuration object used by a servlet container to pass information to a servlet during initialization.
ServletContext	Defines a set of methods that a servlet uses to communicate with its servlet container, for example, to get the MIME type of a file, dispatch requests, or write to a log file.
ServletContextAttributeListener	Implementations of this interface receive notifications of changes to the attribute list on the servlet context of a web application.
ServletContextListener	Implementations of this interface receive notifications about changes to the servlet context of the web application they are part of.
ServletRequest	Defines an object to provide client request information to a servlet.
ServletRequestAttributeListener	A ServletRequestAttributeListener can be implemented by the developer interested in being notified of request attribute changes.
ServletRequestListener	A ServletRequestListener can be implemented by the developer interested in being notified of requests coming in and out of scope in a web component.
ServletResponse	Defines an object to assist a servlet in sending a response to the client.
SingleThreadModel	Deprecated. As of Java Servlet API 2.4, with no direct replacement.

Class Summary

GenericServlet	Defines a generic, protocol-independent servlet.
ServletContextAttributeEvent	This is the event class for notifications about changes to the attributes of the servlet context of a web application.
ServletContextEvent	This is the event class for notifications about changes to the servlet context of a web application.
ServletInputStream	Provides an input stream for reading binary data from a client request, including an efficient readLine method for reading data one line at a time.
ServletOutputStream	Provides an output stream for sending binary data to the client.
ServletRequestAttributeEvent	This is the event class for notifications of changes to the attributes of ServletRequest in an application.
ServletRequestEvent	Events of this kind indicate lifecycle events for a ServletRequest.
ServletRequestWrapper	Provides a convenient implementation of the ServletRequest interface that can be subclassed by developers wishing to adapt the request to a Servlet.
ServletResponseWrapper	Provides a convenient implementation of the ServletResponse interface that can be subclassed by developers wishing to adapt the response from a Servlet.

Exception Summary

ServletException	Defines a general exception a servlet can throw when it encounters difficulty.
UnavailableException	Defines an exception that a servlet or filter throws to indicate that it is permanently or temporarily unavailable.

Package javax.servlet Description

This chapter describes the javax.servlet package. The chapter includes content that is generated automatically from javadoc embedded in the actual Java classes and interfaces. This allows the creation of a single, authoritative, specification document.

Generic Servlet Interfaces and Classes

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

The Servlet interface is the central abstraction of the servlet API. All servlets implement this interface either directly, or more commonly, by extending a class that implements the interface. The two classes in the servlet API that implement the Servlet interface are GenericServlet and HttpServlet . For most purposes, developers will extend HttpServlet to implement their servlets while implementing web applications employing the HTTP protocol.

The basic Servlet interface defines a service method for handling client requests. This method is called for each request that the servlet container routes to an instance of a servlet.

The javax.servlet package

The following section summarizes the javax.servlet package: