This function throws a StringIndexOutOfBounds if the words collection is 
empty ...

class SimpleNamingContext ... {
...

     public static String joinWithString(String seperator, Collection<?> 
words) {
         String ret = "";
         for (Object s: words) {
             ret+=s.toString()+seperator;
         }
         return ret.substring(0, ret.length()-seperator.length());
     }