"Failed to load application class" error with 6.3 nightly

General
1

First a confession; I’m probably doing something stupid here by trying to use 6.3 when I’m not yet familiar with, well, anything Java. At the moment, I’m trying to work with nightly builds because Eclipse seems to be happy to pull them in. So if I’m just being really pigheaded stupid by doing this and my questions aren’t worth answering, please feel free to let me know. But if I can contribute by finding some rough spots in 6.3, I’m happy to try.

Down to business;

I’m trying to follow the AddressBook tutorial with 6.3.0.nightly-20100201-c11069 on Mac OS X 10.6 and I’ve hit the following error:

javax.servlet.ServletException: Failed to load application class: com.example.addressbook.AddressbookApplication
	com.vaadin.terminal.gwt.server.ApplicationServlet.init(ApplicationServlet.java:71)

Eclipse’s “Markers” pane gives me the following hints:

Classpath entry VAADIN_DOWNLOAD/gwt-dev/2.0.0/gwt-dev-mac.jar will not be exported or published. Runtime ClassNotFoundExceptions may result.  	AddressBook		P/AddressBook	Classpath Dependency Validator Message
Classpath entry VAADIN_DOWNLOAD/gwt-user/2.0.0/gwt-user.jar will not be exported or published. Runtime ClassNotFoundExceptions may result.  	AddressBook		P/AddressBook	Classpath Dependency Validator Message
Project 'AddressBook' is missing required library: '/Applications/eclipse/configuration/com.vaadin.integration.eclipse/download/gwt-dev/2.0.0/gwt-dev-mac.jar'	AddressBook		Build path	Build Path Problem

And sure enough, /Applications/…/download/gwt-dev is an empty folder, although gwt-user/2.0.0/gwt-user.jar exists. Is there something I should be doing to populate that gwt-dev folder? And if so with what, considering that GWT 2.0 no longer has separate Lin/Win/Mac branches?

2

To use the Vaadin Eclipse plugin with Vaadin 6.3, you should use the experimental branch of the plugin.

Use the update site http://vaadin.com/eclipse/experimental .

You might have to toggle the Vaadin version to 6.2 and then back to 6.3 when upgrading the plugin to force it to load the GWT 2.0 libraries.

3

I had to kick Eclipse in the head once, (i.e. force quit) but it seems to be working now. Or at least, I get a “Hello Vaadin user” screen.

Thanks for the speedy help!

Oh, and I didn’t need to do anything special to get it to download the GWT 2.0 dev stuff, which was nice to see.