ServletMapping

ServletMapping is a configuration element used in Java web applications to associate a URL pattern with a specific servlet. This mapping allows the web container, such as Apache Tomcat or Jetty, to direct incoming HTTP requests to the correct servlet for processing.

The ServletMapping is typically defined within the web application's deployment descriptor, which is a file named web.xml. Alternatively, it can be configured using annotations in more recent Java EE versions. A ServletMapping entry includes two main components: a servlet-name, which refers to a previously defined servlet, and a url-pattern, which specifies the URL path that should trigger this servlet.

For instance, a mapping might associate the servlet named "helloServlet" with the URL pattern "/hello". When a user requests http://yourwebapp.com/hello, the web container will identify this mapping and forward the request to the "helloServlet" instance. Multiple URL patterns can be mapped to a single servlet, and conversely, different servlets can be mapped to different URL patterns. This mechanism is fundamental to how Java web applications handle requests and route them to the appropriate application logic.