Scala & vaadin "Hello world" Can't publish to tomcat 8

Hi, I’m new to Vaadin and also to Scala, eclipse and tomcat. I am a  old programmer and I’m determined to learn scala and vaadin. But I’m frustrated after two weeks o searching solution for my problem. Y can’t run the “Hello World” demo. With java works perfectly and with scala can’t publish.
I have compiled this piece of code and can’t publish to de tomcat server.

This is the code:

package com.example.vp
 
import javax.servlet.annotation.WebServlet
import com.vaadin.annotations.Theme
import com.vaadin.annotations.VaadinServletConfiguration
import com.vaadin.server.VaadinRequest
import com.vaadin.server.VaadinServlet
import com.vaadin.ui.Button
import com.vaadin.ui.Button.ClickEvent
import com.vaadin.ui.Label
import com.vaadin.ui.UI
import com.vaadin.ui.VerticalLayout
import com.vaadin.ui.Notification
import java.util.Date
import com.vaadin.ui.Button.ClickListener
 
 
@SuppressWarnings(Array("serial"))
@SerialVersionUID(1L)
@Theme("vp")
//7
class p extends UI {
  @WebServlet(value = Array("/*"), asyncSupported = true)
      @VaadinServletConfiguration(productionMode = false, ui = classOf[p])
             class Servlet extends VaadinServlet {
  } 
 
  override def init(request: VaadinRequest) = {
      val content: VerticalLayout = new VerticalLayout
      setContent(content)
      val label: Label = new Label("Hello, world!")
      content addComponent label
      content addComponent new Button("Click Me!",
  new ClickListener {
    override def buttonClick(event: ClickEvent) =
      Notification.show("The time is " + new Date)
})
}
}

This is the error:

Estado HTTP 500 - Error instanciando clase de servlet com.example.vp.p$Servlet
type Informe de Excepción
mensaje Error instanciando clase de servlet com.example.vp.p$Servlet
descripción El servidor encontró un error interno que hizo que no pudiera rellenar este requerimiento.
excepción
javax.servlet.ServletException: Error instanciando clase de servlet com.example.vp.p$Servlet
         org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
         org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
         org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
         org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518)
         org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091)
         org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:673)
         org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1500)
         org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1456)
         java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
         java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
         org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
         java.lang.Thread.run(Unknown Source)
causa raíz
java.lang.InstantiationException: com.example.vp.p$Servlet
         java.lang.Class.newInstance(Unknown Source)
         org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
         org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
         org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
         org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518)
         org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091)
         org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:673)
         org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1500)
         org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1456)
         java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
         java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
         org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
         java.lang.Thread.run(Unknown Source)
causa raíz
java.lang.NoSuchMethodException: com.example.vp.p$Servlet.<init>()
         java.lang.Class.getConstructor0(Unknown Source)
         java.lang.Class.newInstance(Unknown Source)
         org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
         org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
         org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
         org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518)
         org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091)
         org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:673)
         org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1500)
         org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1456)
         java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
         java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
         org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
         java.lang.Thread.run(Unknown Source)
 
Is this code correct? Is there something missing?
Im using vaadin 7 , Eclipse Mars.1.
Thanks in advance