001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 package org.apache.commons.collections.iterators; 018 019 import java.util.Iterator; 020 021 import org.apache.commons.collections.ResettableIterator; 022 023 /** 024 * Provides an implementation of an empty iterator. 025 * <p> 026 * This class provides an implementation of an empty iterator. 027 * This class provides for binary compatability between Commons Collections 028 * 2.1.1 and 3.1 due to issues with <code>IteratorUtils</code>. 029 * 030 * @since Commons Collections 2.1.1 and 3.1 031 * @version $Revision: 646777 $ $Date: 2008-04-10 13:33:15 +0100 (Thu, 10 Apr 2008) $ 032 * 033 * @author Stephen Colebourne 034 */ 035 public class EmptyIterator extends AbstractEmptyIterator implements ResettableIterator { 036 037 /** 038 * Singleton instance of the iterator. 039 * @since Commons Collections 3.1 040 */ 041 public static final ResettableIterator RESETTABLE_INSTANCE = new EmptyIterator(); 042 /** 043 * Singleton instance of the iterator. 044 * @since Commons Collections 2.1.1 and 3.1 045 */ 046 public static final Iterator INSTANCE = RESETTABLE_INSTANCE; 047 048 /** 049 * Constructor. 050 */ 051 protected EmptyIterator() { 052 super(); 053 } 054 055 }