What Is a Servlet?
A servlet is a Java programming language class used to extend the capabilities of servers that host applications accessed by means of a request-response programming model. Although servlets can respond to
any type of request, they are commonly used to extend the applications hosted by web servers. For such applications, Java Servlet technology defines HTTP-specific servlet classes.
The javax.servlet
and
javax.servlet.http
packages provide interfaces and classes for writing servlets. All servlets must implement the
Servlet
interface, which defines lifecycle methods. When implementing a generic service, you can use or extend the
GenericServlet
class provided with the Java Servlet API. The HttpServlet
class provides methods, such as
doGet
and doPost
, for handling HTTP-specific services.