| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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 java.util; |
| |
| /** |
| * An iterator over a sequence of objects, such as a collection. |
| * |
| * <p>If a collection has been changed since the iterator was created, |
| * methods {@code next} and {@code hasNext()} may throw a {@code ConcurrentModificationException}. |
| * It is not possible to guarantee that this mechanism works in all cases of unsynchronized |
| * concurrent modification. It should only be used for debugging purposes. Iterators with this |
| * behavior are called fail-fast iterators. |
| * |
| * <p>Implementing {@link Iterable} and returning an {@code Iterator} allows your |
| * class to be used as a collection with the enhanced for loop. |
| * |
| * @param <E> |
| * the type of object returned by the iterator. |
| */ |
| public interface Iterator<E> { |
| /** |
| * Returns true if there is at least one more element, false otherwise. |
| * @see #next |
| */ |
| public boolean hasNext(); |
| |
| /** |
| * Returns the next object and advances the iterator. |
| * |
| * @return the next object. |
| * @throws NoSuchElementException |
| * if there are no more elements. |
| * @see #hasNext |
| */ |
| public E next(); |
| |
| /** |
| * Removes the last object returned by {@code next} from the collection. |
| * This method can only be called once between each call to {@code next}. |
| * |
| * @throws UnsupportedOperationException |
| * if removing is not supported by the collection being |
| * iterated. |
| * @throws IllegalStateException |
| * if {@code next} has not been called, or {@code remove} has |
| * already been called after the last call to {@code next}. |
| */ |
| public void remove(); |
| } |