Java enum extends workaround

Question

Is there a better \"workaround\" than this? I want to avoid the use of a PREFIX (local var) when accessing the methods on TableMap.

public class TableMap ext         


        

Answer 1

I think you may be trying to put too much intelligence into the enum.

I have found this approach very useful. It avoids many of the issues arising from the fact that you cannot extend enums (well actually you can but not in a very useful way).

Essentially, make the enum a sub-class and pass its characteristics up to your super class as an EnumSet. This way you still get all the benefits of enums including type safety.

public static class MappedEnum> extends TreeMap {
  public MappedEnum(EnumSet e) {
    // Whatever you like with the set.
  }

  public void method(E e) {
  }

}

public static class Foo extends MappedEnum {
  public enum Tables {
    table1, table2, table3;
  }

  public Foo() {
    super(EnumSet.allOf(Tables.class));
  }

  @Override
  public void method(Foo.Tables e) {
  }

}

You could probably even use an EnumMap instead of your TreeMap for better efficiency.