Classpath entry VAADIN_DOWNLOAD

General
1

I apologise in advance if this is too trivial but I’m completely new to vaadin but also fairly new to eclipse and Java also. I’m trying to get my first HelloWorld style vaadin application working. The error I’m getting in eclipse is:

Classpath entry VAADIN_DOWNLOAD/gwt-user/2.1.1/gwt-user.jar will not be exported or published. Runtime ClassNotFoundExceptions may result.

I have set an environment variable VAADIN_DOWNLOAD to point to where my gwt-user folder was downloaded to but that didn’t seem to help.

Can someone point me in the right direction?

Thanks! Rob.

2

To create a HelloWorld application, all you should need to do is “New… → Vaadin Project” and then “Run As… → Run on server” or “Export… → WAR” to a server. This classpath variable should be automatically set by the plugin to point to the directory where the Vaadin plugin automatically downloads the correct versions of the required JARs, and all other settings should also be correct “out of the box”.

As for the warning, that JAR is primarily used in code that will be compiled to JavaScript (the widgetset), so IIRC not having it in a WAR that you deploy onto a server should not be a problem - as long as the correct widgetset (either one you have compiled yourself or the default one inside Vaadin JAR) is in the WAR, directly or in the Vaadin JAR.

3

OK thanks. I had been using Run As … Run on Server using a Tomcat 7 server. It didn’t seem to work but I will try again tonight now that you have helped me understand what is required.

4

OK I have it working now. I think all it was is that my project needed to be refreshed in the navigator view. One step forward. -_-

5

I have imported my Eclipse project from an environment with the Vaadin plugin, to an evironment that does not have the plugin. The only thing stopping my project being buit is the missing VAADIN_DOWNLOAD variable. Could you give me a concrete example of how I might be able to set this up manually? With a good example, I should be able to work it out for my own specific needs. Thanks.

6

If you don’t want to use the plugin, either change the paths manually or set the classpath variable in Preferences → Java → Build Path → Classpath Variables .

7

Henri - thanks for the quick response. I already know
where
 and
how
 to set up the variable, I’m just not sure
what
 to set it to … are you able to tell me
what
 it is set to in your environment? (for example?) I hope I don’t sound rude … thanks.

8

OK, after much effort, I am now in a position to answer my own question :slight_smile:

Vaadin has configured the VAADIN_DOWNLOAD variable in my eclipse environment to:

\configuration\com.vaadin.integration.eclipse\download

Where in my case was ‘D:\eclipse’.

9

This is where the Vaadin plug-in for Eclipse automatically downloads the correct (Vaadin and) GWT JARs from http://vaadin.com/download/external/gwt/ and other locations. If you do not have the Vaadin plug-in installed, though, you might want to point the variable at another directory where you have manually downloaded the JARs. The correct version can be found in the manifest of the Vaadin JAR as well as in the file META-INF/GWT.version in the Vaadin JAR.