<code lang="Java">
package my.package;

import org.whatever.*;
import org.whateverElse.*;   // you can end up with a lot of jarfile dependancies

public class MyClass {
   public static void main(String[] args) throws Exception {
      // ... code uses whatever & classloader needs those jarfiles
   }
}

Normally, you would run it like this:

java -cp c:\foo\lib\whatever.jar;c:\foo\lib\whateverElse.jar ... my.package.MyClass [args]

This can get tedious listing every jarfile, especially if they are all in the same directory anyway.  I've always thought you should just be able to say -cp c:\lib\*.jar.  That doesn't work, but here's how to get the same effect:

java -Djava.ext.dirs=c:\foo\lib my.package.MyClass [args]
</code>
There are drawbacks to using this technique in production systems, but it's nice for quick development.  You can also list more than one directory, separated like CLASSPATH elements with either : or ;.