javax.servlet.UnavailableException: Servlet class com.vaadin.terminal.gwt.s

General
1

Hi all,

I’m fairly new to vaadin, but so far all I can say is: awesome work!

I’m having a problem running my application. I’m deploying it to a Jetty server at runtime, as I start the server I’m getting this exception:

HTTP ERROR 404

Problem accessing /prova-vaadin. Reason:

Servlet class com.vaadin.terminal.gwt.server.ApplicationServlet is not a javax.servlet.Servlet

Caused by:

javax.servlet.UnavailableException: Servlet class com.vaadin.terminal.gwt.server.ApplicationServlet is not a javax.servlet.Servlet
at org.eclipse.jetty.servlet.ServletHolder.checkServletType(ServletHolder.java:339)
at org.eclipse.jetty.servlet.ServletHolder.doStart(ServletHolder.java:225)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:55)
at org.eclipse.jetty.servlet.ServletHandler.initialize(ServletHandler.java:694)
at org.eclipse.jetty.servlet.ServletContextHandler.startContext(ServletContextHandler.java:193)
at org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:966)
at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:586)
at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:349)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:55)
at org.eclipse.jetty.server.handler.HandlerWrapper.doStart(HandlerWrapper.java:92)
at org.eclipse.jetty.server.Server.doStart(Server.java:230)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:55)
at paripari.GUI.ServerStarter.startServer(ServerStarter.java:47)
at paripari.GUI.GUI.init(GUI.java:117)
at paripari.plugin.Plugin.go(Plugin.java:313)
at paripari.core.PariPariRunnable.run(PariPariRunnable.java:99)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)

of which I can’t figure out the cause. If I run the application on Tomcat 6 or Jetty in eclipse everything goes fine.

Maybe I’m doing something wrong with the project setup: I have the gwt-dev and gwt-user jars, along with java servlet-api, vaadin and refresher jars, in my WebContent/WEB-INF/lib folder.

This is the web.xml:


<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
  <display-name>prova-vaadin</display-name>
  <context-param>
  	<description>
  	Vaadin production mode</description>
  	<param-name>productionMode</param-name>
  	<param-value>false</param-value>
  </context-param>
  <servlet>
  	<servlet-name>Prova_vaadin Application</servlet-name>
  	<servlet-class>
  	com.vaadin.terminal.gwt.server.ApplicationServlet</servlet-class>
  	<init-param>
  		<description>
  		Vaadin application class to start</description>
  		<param-name>application</param-name>
  		<param-value>com.example.prova_vaadin.Prova_vaadinApplication</param-value>
  	</init-param>
  	<init-param>
  		<description>
  		Application widgetset</description>
  		<param-name>widgetset</param-name>
  		<param-value>com.example.prova_vaadin.widgetset.Prova_vaadinWidgetset</param-value>
  	</init-param>
  </servlet>
  <servlet-mapping>
  	<servlet-name>Prova_vaadin Application</servlet-name>
  	<url-pattern>/*</url-pattern>
  </servlet-mapping>
  <servlet-mapping>
  	<servlet-name>Prova_vaadin Application</servlet-name>
  	<url-pattern>/VAADIN/*</url-pattern>
  </servlet-mapping>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
</web-app>
2

Hi,

Normally you’d only have the vaadin and refresher jars in WEB-INF/lib (and your problem sure sounds like a classloading problem).

(Did you use the Vaadin Eclipse plugin to set up the project structure? You don’t have to, but it might help.)

Best Regards,
Marc

3

Hi Marc,
thanks for the fast response.
Yes, I’m using the eclipse plugin, but I somehow still managed to mess it up :smiley:

As you suggested, I removed everythig from my WEB-INF/lib folder but the vaadin and refresher jars. I imported the whole gwt directory, moved the servlet-api jar to a /lib folder in the project root directory.

As I moved the servlet-api jar, the exception changed into a plain:

java.lang.NoClassDefFoundError: javax/servlet/http/HttpServlet
at java.lang.ClassLoader.defineClass1(Native Method)
… (full stack trace included in the attached file)

This is why I put all the jars in the WEB-INF/lib folder in the first place. Should I export in some way the gwt libraries when making the WAR?
11391.txt (3.17 KB)

4

Hi,

Try making a new project with the plugin and look how that’s structured; in the first screenshot attached I did a new Vaadin Project, pressed finish, and got the structure in the second. This project should work when you do a ‘Export as WAR’. Add-on jars can be drag&dropped into WEB-INF/lib, and the whole thing should still work.

Best Regards,
Marc
[b]

NOTE: everything under “Libraries” is added automatically - no need to manually include servlet jars etc.
[/b]
11394.png
11395.png