Configuring web applications programmatically

In addition to allowing us to configure web applications through annotations and web-fragment.xml, Servlet 3.0 also allows us to configure our web applications programmatically at runtime.

The ServletContext class has new methods to configure servlets, filters, and listeners programmatically. The following example illustrates how to configure a servlet programmatically at runtime, without resorting to the @WebServlet annotation or to XML:

package com.ensode.jakartaeebook.servlet;
//imports omitted
@WebListener()
public class ServletContextListenerImpl implements
  ServletContextListener {
  @Override
  public void contextInitialized(
    ServletContextEvent servletContextEvent) {
    ServletContext servletContext = servletContextEvent.
      getServletContext();
    try {
      ProgrammaticallyConfiguredServlet...