/* * Copyright (c) 2013 Mike Heath. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * */ package cloudeventbus.client; import java.util.Iterator; import java.util.NoSuchElementException; import java.util.concurrent.TimeUnit; /** * An {@link Iterator} for iterating over {@link Message} objects. * * @author Mike Heath <elcapo@gmail.com> */ public interface MessageIterator extends AutoCloseable, Iterator<Message> { /** * Closes the iterator. */ @Override void close(); /** * Returns {@code true} unless the iterator has been closed. If the {@link Request} or {@link Subscription} from which * this iterator was created are closed, this iterator will be closed automatically. * * @return {@code true} unless the iterator has been closed. */ @Override boolean hasNext(); /** * Blocks until a message is received. If this iterator is closed while this method blocks, it will throw a * {@link ClientClosedException}. * * @return the received message. * @throws ClientClosedException if the iterator is closed while waiting for a message to arrive. * @throws ClientInterruptedException if the blocked thread is interrupted while waiting for a message. * @throws NoSuchElementException if the iteration has no more elements */ @Override Message next() throws ClientClosedException, ClientInterruptedException, NoSuchElementException; /** * Throws an {@link UnsupportedOperationException}. * * @throws UnsupportedOperationException it does not even make sense to remove a received message. */ @Override void remove() throws UnsupportedOperationException; /** * Blocks until a message is received. * * @return the received message. * @throws ClientClosedException if the iterator has been closed. * @throws ClientInterruptedException if the blocked thread is interrupted while waiting for a message. * @throws NoSuchElementException if the iteration has no more elements */ Message next(long timeout, TimeUnit unit) throws ClientClosedException, ClientInterruptedException, NoSuchElementException; }