This is what a constant expression in Java looks like:
package com.mycompany.mypackage;
public class MyLinks {
// constant expression
public static final String GUESTBOOK_URL = "/guestbook";
}
You can use it with annotations as following:
import com.mycompany.mypackage.MyLinks;
@WebServlet(urlPatterns = {MyLinks.GUESTBOOK_URL})
public class GuestbookServlet extends HttpServlet {
// ...
}