Empty Enumeration in Java 6

Question

Java 7 provides the convenience method

Collections.emptyEnumeration()

But this is not available in Java 6.

Is there an empty enumeration class lurking elsewhere in the JDK, or do I need to roll my own?

Answer 1

You can simply use

Collections.enumeration(Collections.emptyList());

Answer 2

there is no empty Enumeration in JDK 6, but you can use the source code from jdk 7

    /*
     * taken from jdk source
     * @since 1.7
     */
    public static <T> Enumeration<T> emptyEnumeration() {
        return (Enumeration<T>) EmptyEnumeration.EMPTY_ENUMERATION;
    }

    private static class EmptyEnumeration<E> implements Enumeration<E> {
        static final EmptyEnumeration<Object> EMPTY_ENUMERATION
            = new EmptyEnumeration<>();

        public boolean hasMoreElements() { return false; }
        public E nextElement() { throw new NoSuchElementException(); }
    }