/*
* 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: 155406 $ $Date: 2005-02-26 12:55:26 +0000 (Sat, 26 Feb 2005) $
*
* @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
}
}