Class Enum

Basic enum class for type-safe enums. Should be used as an abstract base. For example:

 import org.apache.avalon.framework.Enum;

 public final class Color extends Enum {
   public static final Color RED = new Color( "Red" );
   public static final Color GREEN = new Color( "Green" );
   public static final Color BLUE = new Color( "Blue" );

   private Color( final String color )
   {
     super( color );
   }
 }
 

If further operations, such as iterating over all items, are required, the Enum(String, Map) constructor can be used to populate a Map, from which further functionality can be derived:

 public final class Color extends Enum {
   static final Map map = new HashMap();

   public static final Color RED = new Color( "Red", map );
   public static final Color GREEN = new Color( "Green", map );
   public static final Color BLUE = new Color( "Blue", map );

   private Color( final String color, final Map map )
   {
     super( color, map );
   }

   public static Iterator iterator()
   {
     return map.values().iterator();
   }
 }
 

NOTE: between 4.0 and 4.1, the constructors' access has been changed from public to protected. This is to prevent users of the Enum breaking type-safety by defining new Enum items. All Enum items should be defined in the Enum class, as shown above.