ReadOnlyIterator Class — netty Architecture

Source Code

codec-http2/src/main/java/io/netty/handler/codec/http2/ReadOnlyHttp2Headers.java lines 840–891

    private final class ReadOnlyIterator implements Map.Entry<CharSequence, CharSequence>,
                                                    Iterator<Map.Entry<CharSequence, CharSequence>> {
        private int i;
        private AsciiString[] current = pseudoHeaders.length != 0 ? pseudoHeaders : otherHeaders;
        private AsciiString key;
        private AsciiString value;

        @Override
        public boolean hasNext() {
            return i != current.length;
        }

        @Override
        public Map.Entry<CharSequence, CharSequence> next() {
            if (!hasNext()) {
                throw new NoSuchElementException();
            }
            key = current[i];
            value = current[i + 1];
            i += 2;
            if (i == current.length && current == pseudoHeaders) {
                current = otherHeaders;
                i = 0;
            }
            return this;
        }

        @Override
        public CharSequence getKey() {
            return key;
        }

        @Override
        public CharSequence getValue() {
            return value;
        }

        @Override
        public CharSequence setValue(CharSequence value) {
            throw new UnsupportedOperationException("read only");
        }

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

        @Override
        public String toString() {
            return key.toString() + '=' + value.toString();
        }
    }