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; 018 019 /** 020 * Defines an iterator that operates over an ordered <code>Map</code>. 021 * <p> 022 * This iterator allows both forward and reverse iteration through the map. 023 * 024 * @since Commons Collections 3.0 025 * @version $Revision: 646777 $ $Date: 2008-04-10 13:33:15 +0100 (Thu, 10 Apr 2008) $ 026 * 027 * @author Stephen Colebourne 028 */ 029 public interface OrderedMapIterator extends MapIterator, OrderedIterator { 030 031 /** 032 * Checks to see if there is a previous entry that can be iterated to. 033 * 034 * @return <code>true</code> if the iterator has a previous element 035 */ 036 boolean hasPrevious(); 037 038 /** 039 * Gets the previous <em>key</em> from the <code>Map</code>. 040 * 041 * @return the previous key in the iteration 042 * @throws java.util.NoSuchElementException if the iteration is finished 043 */ 044 Object previous(); 045 046 }