Multiple Vaadin apps, JSPs and 3rd party servlets in a same project

Flow
1

Hi! I’m converting a Vaadin Framework project with

  • multiple path specific servlets for different Vaadin apps
  • JSPs
  • 3rd party servlets like barcode4j

to Vaadin Flow 24.

So, I need to get these URLs working:

The converted project is based on base-starter-gradle.

With VaadinServlet URL pattern /vaadin/* and @Route("app-1") and @Route("app-2")

work fine but aren’t feasible because /vaadin-app-1 and /vaadin-app-2 are stored in bookmarks, documents etc.

It is possible to

  • extend VaadinServlet → App1Servlet & App2Servlet with URL patterns /vaadin-app-1/* and /vaadin-app-2/*
  • set @Route("") for App1Component and App2Component

but is it possible to assign App1Component to App1Servlet and App2Component to App2Servlet? How?

2

You could use your reverse proxy in front of your application to automatically rewrite the URLs and inform your users that they should update their bookmarks.

3

@knoobie, thanks. That’s an option, but I’d rather implement this inside a war package if possible.

4

After implementing this method in the both servlet classes

@Override
protected VaadinServletService createServletService() throws ServletException {
    VaadinServletService service = null;
    try {
        service = super.createServletService();
        RouteConfiguration config = RouteConfiguration.forRegistry(service.getRouter().getRegistry());
        config.setRoute("", App1Component.class); // App2Component.class in another servlet
    } catch (ServiceException e) {
        throw new ServletException(e.getMessage(), e);
    }
    return service;
}

the following exception is thrown:

com.vaadin.flow.server.AmbiguousRouteConfigurationException: Navigation targets must have unique routes, found navigation targets ‘com.example.App1Component’ and ‘com.example.App1Component’ with the same route.

→ Maybe it is not possible to implement what was requested.

5

If the Vaadin “apps” single views (e.g. you land on /vaadin-app-1 and there are no other views like /vaadin-app-1/something), and the concern is limited to links stored somewhere, you can perhaps setup a Servlet Filter to perform a permanent redirect, e.g. from /vaadin-app-1 to /vaadin/app-1.

Another potential solution, assuming third-party servlets have specific mappings, could be to have a custom Vaadin Servlet mapped to /*, that forwards JSPs to the default servlet (or you can map the default servlet to *.jsp in web.xml). However, this solution would be specific to the servlet container. For example, with Jetty you can probably do something like

@WebServlet(asyncSupported = true, urlPatterns = {"/*", "/VAADIN/*"})
public class MyVaadinServlet extends VaadinServlet {

    @Override
    protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        if (request.getRequestURI().endsWith(".jsp")) {
            request.getServletContext().getNamedDispatcher("jsp").forward(request, response);
        } else {
            super.service(request, response);
        }
    }
}
6

Thank you @marcoc_753! request.getServletContext().getNamedDispatcher("jsp").forward(request, response) seems to work in Tomcat also.