UIProvider stacktrace

Vaadin 6 / 7 / 8
1

I created a Vaadin project with Maven archetype (using Netbeans).
Than I tried switching Servlet API from 2.4 to 3.0 with changes in attached web.xml

Now I get following stacktrace on project startup:


SEVERE: Servlet.service() for servlet [MyVaadinUI]
 in context with path 
[/BrazzoVaadin] threw exception
 [com.vaadin.server.ServiceException: com.vaadin.server.ServiceException: 
No UIProvider has been added and there is no "UI" init parameter.] with root cause
com.vaadin.server.ServiceException: No UIProvider has been added and there is no "UI" init parameter.
	at com.vaadin.server.ServletPortletHelper.checkUiProviders(ServletPortletHelper.java:179)
	at com.vaadin.server.VaadinService.onVaadinSessionStarted(VaadinService.java:740)
	at com.vaadin.server.VaadinService.createAndRegisterSession(VaadinService.java:699)
	at com.vaadin.server.VaadinService.doFindOrCreateVaadinSession(VaadinService.java:655)
	at com.vaadin.server.VaadinService.findOrCreateVaadinSession(VaadinService.java:596)
	at com.vaadin.server.VaadinService.findVaadinSession(VaadinService.java:479)
	at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1323)
	at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:236)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
	at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1023)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:724)

I already tried adding ‘UI’ or ‘UIProvider’ init-param in web.xml providing my UI class (which extends com.vaadin.ui.UI) but then I get error that my class doesn’t extend UIProvider.

How can I fix my setup ?

TIA

2

Sorry, forgot to attach web.xml…
13089.xml (903 Bytes)

3

For the “UI” (or “ui”) parameter you need to give the fully qualified class name of your UI class - the application should find the UI if you add this init parameter correctly.

Alternatively, you can use a custom UIProvider class, but that should not be necessary unless you want to customize UI class selection and instantiation e.g. based on the device type (mobile vs. desktop).

4

Thanks for replying, got it working again. Seems I made a silly mistake in my web.xml indeed…