Using Spring MVC 3.1+ WebApplicationInitializer to programmatically configure session-config and error-page

Question

WebApplicationInitializer provides a way to programmatically represent a good portion of a standard web.xml file - the servlets, filters, listeners.

However I have

Answer 1

Extending on BwithLove comment, you can define 404 error page using exception and controller method which is @ExceptionHandler:

1. Enable throwing NoHandlerFoundException in DispatcherServlet.
2. Use @ControllerAdvice and @ExceptionHandler in controller.

WebAppInitializer class:

public class WebAppInitializer implements WebApplicationInitializer {
@Override
public void onStartup(ServletContext container) {
    DispatcherServlet dispatcherServlet = new DispatcherServlet(getContext());
    dispatcherServlet.setThrowExceptionIfNoHandlerFound(true);
    ServletRegistration.Dynamic registration = container.addServlet("dispatcher", dispatcherServlet);
    registration.setLoadOnStartup(1);
    registration.addMapping("/");
}

private AnnotationConfigWebApplicationContext getContext() {
    AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();
    context.setConfigLocation("com.my.config");
    context.scan("com.my.controllers");
    return context;
}
}

Controller class:

@Controller
@ControllerAdvice
public class MainController {

    @RequestMapping(value = "/")
    public String whenStart() {
        return "index";
    }


    @ExceptionHandler(NoHandlerFoundException.class)
    @ResponseStatus(value = HttpStatus.NOT_FOUND)
    public String requestHandlingNoHandlerFound(HttpServletRequest req, NoHandlerFoundException ex) {
        return "error404";
    }
}

"error404" is a JSP file.