[news.eclipse.newcomer] Re: Delete HelloWorld.class file, won't run agai

[Eric Rizzo <eclipse@xxxxxxxxxxxx>]

Diviner wrote:
> Hi all,
>
> I tried to write a simple console application "HelloWorld" and
> work well in a development cycle. Then I tried to delete the
> HelloWorld.class to let Eclipse make it for me again, but
> always failed. It gave me the error:
>    java.lang.NoClassDefFoundError: HelloWorld
>    Exception in thread "main"
>    (with a dialog -- "Could not find the main class. Program will exit")

After you deleted the .class file, how did you tell Eclipse to 
re-compile it for you? In a standard configuration, Eclipse will 
re-build the project (re-compile all Java source files) when you make a 
change to the source and save it, or if you select Project > Clean from 
the menu.

HTH,
	Eric