How do I configure DispatcherServlet without using web.xml in Spring MVC?

public class WebAppInitializer implements WebApplicationInitializer {
   public void onStartup(ServletContext servletContext) throws ServletException {  
        AnnotationConfigWebApplicationContext ctx = new AnnotationConfigWebApplicationContext();  
        ctx.register(ApplicationConfig.class);  
        ctx.setServletContext(servletContext);    
        Dynamic dynamic = servletContext.addServlet("dispatcher", new DispatcherServlet(ctx));  
        dynamic.addMapping("/");  
        dynamic.setLoadOnStartup(1);  
   }  
}