Re: limitations on using enum as generic parameter

From:
Lew <lew@lewscanon.com>
Newsgroups:
comp.lang.java.programmer
Date:
Tue, 8 Feb 2011 10:38:57 -0800 (PST)
Message-ID:
<c93f15ae-9766-42f3-9bb0-18cea537e111@u14g2000vbg.googlegroups.com>
On Feb 8, 1:34 pm, markspace <nos...@nowhere.com> wrote:

On 2/8/2011 9:50 AM, dal...@cs.queensu.ca wrote:

situations, I tried writing a generic class that takes an enum as a
type parameter. Unfortunately I don't seem to be able to invoke the
enum's values() method -- javac says "Cannot find symbol: method


Yes, values() and valueOf(String) are /static/ methods. They don't
appear on the Enum interface so the compiler doesn't know about them.

You can try object.getClass().getEnumConstants() to get the constants
themselves in order.

Also you should probably be declaring you enum as <E extends Enum<E> & ..=

..>.

Untested:

public class EnumCodeSet<E extends Enum<E> & MessageCode>
{
   private final E[] enums;

   public EnumCodeSet( E anEnum ) {
     enums = anEnum.getClass().getEnumConstants);
   }

   public MessageCode index( int i ) {
     return enums[i];
   }

   //... etc.


Also, generics and arrays don't mix. So don't mix them.

--
Lew

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