Re: Generics pains

From:

"Ingo R. Homann" <ihomann_spam@web.de>

Newsgroups:

comp.lang.java.programmer

Date:

Tue, 26 Jun 2007 10:14:11 +0200

Message-ID:

<4680cad3$0$6393$9b4e6d93@newsspool2.arcor-online.net>

Hi,

Joshua Cranmer wrote:

I am trying to create an options class that manages options for a
project. In this class, the options are internally stored as Strings that
can be cast to (depending on circumstances) integers, booleans, or even
enums. However, I am having trouble getting the code to compile:

My suggestiuon (although I am not really sure about it ;-) is this:

class Options
{

   private Options()
   {
   }

   private static HashMap<String, String> opts = new HashMap<String,
String>();

   private static HashMap<String, Class<?>> types = new HashMap<String,
Class<?>>();

   public static String getOption(String name)
   {
     return opts.get(name);
   }

   public static <T extends Enum<T>> T getAsEnum(String name)
   {
     Class<?> c = types.get(name);
     if (!c.isEnum())
       throw new RuntimeException("Option " + name + " is not an enum!");
     @SuppressWarnings("unchecked")
     Class<T> ec = (Class<T>) c.asSubclass(Enum.class);
     return Enum.valueOf(ec, getOption(name));
   }
}

Hth,
Ingo