Important Notice - Forums is archived
To simplify things and help our users to be more productive, we have archived the current forum and focus our efforts on helping developers on Stack Overflow. You can post new questions on Stack Overflow or join our Discord channel.

Vaadin lets you build secure, UX-first PWAs entirely in Java.
Free ebook & tutorial.
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