javaxservlet

javax.servlet is the standard package of the Java Servlet API that defines how Java programs can extend a web server's behavior by handling HTTP requests. It is part of Java EE and, since 2019, Jakarta EE, with the historical package name javax.servlet and its extensions implemented by servlet containers such as Tomcat, Jetty, and GlassFish.

Key interfaces and classes reside in javax.servlet and javax.servlet.http, including Servlet, GenericServlet, HttpServlet, ServletRequest, ServletResponse, HttpServletRequest, HttpServletResponse, ServletContext, ServletConfig, and AsyncContext. HttpServletRequest and HttpServletResponse are the primary entry points for processing client requests in most web applications.

A servlet is managed by a container. Its lifecycle is controlled by the container through init(), service(), and destroy() methods. Developers typically extend HttpServlet and override doGet or doPost to generate responses, using the HttpServletResponse to write output. Servlets are configured via web.xml or annotations such as @WebServlet and deployed inside a WAR.

Evolution and compatibility: javax.servlet was the standard namespace for the Servlet API in Java EE 8 and earlier. With Jakarta EE 9, the namespace was renamed to jakarta.servlet, affecting new applications and libraries. Backward compatibility layers and older containers continue to support javax.servlet for existing code.

See also: Jakarta Servlet, Java Servlet, Java EE, servlet container.