public class QueueArrayBuffer<T> {

    public abstract class Iterator {
        private int i = 0;

        public abstract void next(final T element);

        public final void delete_current() {
            delete(i);
        }
    }

    private final T[] buffer;
    private final int size;
    private int first = 0;
    private int last = 0;

    @SuppressWarnings("unchecked")
    public QueueArrayBuffer(final int size) {
        this.size = size;
        buffer = (T[]) new Object[size];
    }

    public void put(final T element) {
        if ((last + 1) % size == first)
            delete(first);
        last = (last + 1) % size;
        buffer[last] = element;
    }

    private void delete(final int index) {
        buffer[index] = null;
        if (first == index)
            while (buffer[first] == null && first != last)
                first = (first + 1) % size;
    }

    public void iterate(final Iterator iterator) {
        iterator.i = first;
        while (iterator.i != last) {
            if (buffer[iterator.i] != null)
                iterator.next(buffer[iterator.i]);
            iterator.i = (iterator.i + 1) % size;
        }
    }

}