ChannelsReadOnlyIterator Class — netty Architecture

Source Code

transport/src/main/java/io/netty/channel/SingleThreadEventLoop.java lines 200–244

    protected static final class ChannelsReadOnlyIterator<T extends Channel> implements Iterator<Channel> {
        private final Iterator<T> channelIterator;

        public ChannelsReadOnlyIterator(Iterable<T> channelIterable) {
            this.channelIterator =
                    ObjectUtil.checkNotNull(channelIterable, "channelIterable").iterator();
        }

        @Override
        public boolean hasNext() {
            return channelIterator.hasNext();
        }

        @Override
        public Channel next() {
            return channelIterator.next();
        }

        @Override
        public void remove() {
            throw new UnsupportedOperationException("remove");
        }

        @SuppressWarnings("unchecked")
        public static <T> Iterator<T> empty() {
            return (Iterator<T>) EMPTY;
        }

        private static final Iterator<Object> EMPTY = new Iterator<Object>() {
            @Override
            public boolean hasNext() {
                return false;
            }

            @Override
            public Object next() {
                throw new NoSuchElementException();
            }

            @Override
            public void remove() {
                throw new UnsupportedOperationException("remove");
            }
        };
    }