Vaadin 6.3.2 + Scala 2.8 RC2 = java.lang.InstantiationException :(

Hello guys,

I need a little help.

I did three times everything that is wrote here
Dynamic Web Projects in Scala with Eclipse
and every time I’m getting:



2010-05-18 02:13:26 org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet Test3 Application threw exception
java.lang.InstantiationException: com.example.test3.Test3Application
at java.lang.Class.newInstance0(Unknown Source)
at java.lang.Class.newInstance(Unknown Source)
at com.vaadin.terminal.gwt.server.ApplicationServlet.getNewApplication(ApplicationServlet.java:82)
at com.vaadin.terminal.gwt.server.AbstractApplicationServlet.createApplication(AbstractApplicationServlet.java:906)
at com.vaadin.terminal.gwt.server.AbstractApplicationServlet.findApplicationInstance(AbstractApplicationServlet.java:734)
at com.vaadin.terminal.gwt.server.AbstractApplicationServlet.service(AbstractApplicationServlet.java:437)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Unknown Source)

All works good when start application is in Java. When I change it into Scala it generates this error.

I am using latest Vaadin (6.3.2) and Scala (Scala 2.8 RC2).
I am attaching screenshot.

Any suggestions how to solve this problem?
What can I do?

Thanks,
Arthur.

PS: I love Scala and I am using it for 2.5 years, do I understand correctly that I can create Vaadin web applications using Scala instead of Java?? Thanks;)
11284.gif

I solved this problem in this way.

In Application.init() I put only one line :

new ScalaStartup().init( this );

so as fast as I can I’m passing control to scala code.

Just for a start I can tell that Window, Label and Refresher (here how I configure it
http://vaadin.com/forum/-/message_boards/message/77099
) works good from scala.

Thanks:)

Hi Arthur,

Can you please provide some code snippet with the solution that you found for this problem.
I’m currently struggling with the same issue and, unfortunately, I don’t quite understand what you did to solve it!

Thank

Is your Application a Scala object instead of a class? If so, no constructor is generated for it, and it can’t be instantiated with Class.newInstance(). If you change it from object to a class it should work.