001/* 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * https://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, 013 * software distributed under the License is distributed on an 014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 015 * KIND, either express or implied. See the License for the 016 * specific language governing permissions and limitations 017 * under the License. 018 * 019 */ 020package org.apache.directory.api.util; 021 022 023import java.util.ArrayDeque; 024import java.util.Iterator; 025 026 027/** 028 * Collection and Iterator utils. 029 * 030 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> 031 */ 032public final class CollectionUtils 033{ 034 private CollectionUtils() 035 { 036 } 037 038 039 public static <T> Iterator<T> reverse( Iterator<T> iterator ) 040 { 041 ArrayDeque<T> deque = new ArrayDeque<>(); 042 while ( iterator.hasNext() ) 043 { 044 deque.addLast( iterator.next() ); 045 } 046 return deque.descendingIterator(); 047 } 048}