access a java class from within groovy

I have a simple java class:

package test;
class Hello {
  public static void main(String[] args) {
    System.out.println("Hi");
  }
}

on which I do a

javac Hello.java

Problem: Now I would like to access this class from a groovy script (access.groovy) ...

import test.*
Hello.main(null)

but

groovy -cp . access.groovy

will result in a MissingPropertyException . What am I doing wrong?