- /*
- * Copyright 2004 The Apache Software Foundation
- *
- * 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 org.apache.commons.collections.iterators;
-
- import java.util.NoSuchElementException;
-
- /**
- * Provides an implementation of an empty iterator.
- *
- * @since Commons Collections 3.1
- * @version $Revision: 1.2 $ $Date: 2004/05/26 20:57:43 $
- *
- * @author Stephen Colebourne
- */
- abstract class AbstractEmptyIterator {
-
- /**
- * Constructor.
- */
- protected AbstractEmptyIterator() {
- super();
- }
-
- public boolean hasNext() {
- return false;
- }
-
- public Object next() {
- throw new NoSuchElementException("Iterator contains no elements");
- }
-
- public boolean hasPrevious() {
- return false;
- }
-
- public Object previous() {
- throw new NoSuchElementException("Iterator contains no elements");
- }
-
- public int nextIndex() {
- return 0;
- }
-
- public int previousIndex() {
- return -1;
- }
-
- public void add(Object obj) {
- throw new UnsupportedOperationException("add() not supported for empty Iterator");
- }
-
- public void set(Object obj) {
- throw new IllegalStateException("Iterator contains no elements");
- }
-
- public void remove() {
- throw new IllegalStateException("Iterator contains no elements");
- }
-
- public Object getKey() {
- throw new IllegalStateException("Iterator contains no elements");
- }
-
- public Object getValue() {
- throw new IllegalStateException("Iterator contains no elements");
- }
-
- public Object setValue(Object value) {
- throw new IllegalStateException("Iterator contains no elements");
- }
-
- public void reset() {
- // do nothing
- }
-
- }