Hi Justine,
If what you're looking to do is test your GWT code, you are much better off using the GWTTestCase JUnit integration class rather than try to define main methods. In fact, it doesn't make much sense to test GWT code through main methods since what you're really interested in is testing how the code would run in a browser. GWT's hosted mode browser compiles your GWT code into byte code and runs this in the hosted mode browser environment, where it can correctly simulate how your GWT code would run on a regular browser as JavaScript. The GWTTestCase class allows you to run JUnit tests that run hosted mode in the background (
i.e., without popping up the hosted mode browser) so that the code you are testing would run as it would as generated JavaScript in a standard browser.
You can check out more on setting up GWTTestCases on your GWT code to test your application at the link below:
http://code.google.com/webtoolkit/documentation/com.google.gwt.doc.DeveloperGuide.JUnitIntegration.html
Hope that helps,
-Sumit Chandel