Can I change this...

      if (i == CLIENTS)
        List l = selectAllClients();

      for (ListIterator it = l.listIterator(); it.hasNext(); ) {
        if (i == CLIENTS) {
          Client c = (Client) it.next();
          System.out.println(c.getName()+", "+c.getAddress()+", "+c.getPhoneNo());
        }
      }

to this?

      if (i == CLIENTS)
        List l = selectAllClients();

      for (Object o : l) {
        if (i == CLIENTS) {
          Client c = (Client) o;
          System.out.println(c.getName()+", "+c.getAddress()+", "+c.getPhoneNo());
        }
      }