HierarchyEnum.java

public class HierarchyEnum {
    
    public interface Fruit {}
    
    public static enum RedFruit implements Fruit{
        RED_APPLE, TOMATOE;
    }
    
    public static enum OrangeFruit implements Fruit{
        ORANGE, PAPAYA;
    }
    
    public static enum GreenVegetable{
        LETTUCE;
    }
    
    public static enum Fruits {
        RED_FRUIT(RedFruit.class), 
        ORANGE_FRUIT(OrangeFruit.class);
        
        Class<? extends Fruit> classType;
        
        Fruits(Class<? extends Fruit> classType) {
            this.classType = classType;
        }
        
        public Class<? extends Fruit> getValue() {
            return classType;
        }
        
        public static Fruit[] getFruitsValues(Fruits fruits) {
            return fruits.getValue().getEnumConstants();
        }
        
    }
    
    public static void main( String[] args ){
        Object[] array = Fruits.getFruitsValues(Fruits.RED_FRUIT);
        
        for(int i = 0; i< array.length; i++) {
            System.out.println(array[i]);
        }
        
        array = Fruits.getFruitsValues(Fruits.ORANGE_FRUIT);
        
        for(int i = 0; i< array.length; i++) {
            System.out.println(array[i]);
        }
    }
}