Null Pointer Exception

This is why I don't program in Java:

import java.util.ArrayList;

class Program
{
   class Person
   {
       public Person partner;
   }

   class Prostitute extends Person { }
   class Eunich extends Person { }

   private Prostitute prostitute;
   private Eunich eunich;

   public static void main(String[] args) {
       Program p = new Program();
       p.run();
   }

   public void run() {
       eunich.partner = prostitute;
   }
}

> Exception in thread "main" java.lang.NullPointerException

But if you do, you should check out the nifty online JXXX Compiler Service.