| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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.jasper.util; |
| |
| |
| import java.util.ArrayList; |
| import java.util.Enumeration; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.NoSuchElementException; |
| |
| |
| /** |
| * Adapter class that wraps an <code>Enumeration</code> around a Java2 |
| * collection classes object <code>Iterator</code> so that existing APIs |
| * returning Enumerations can easily run on top of the new collections. |
| * Constructors are provided to easily create such wrappers. |
| * |
| * @author Craig R. McClanahan |
| * @version $Id: Enumerator.java,v 1.1 2011/06/28 21:14:19 rherrmann Exp $ |
| */ |
| |
| public final class Enumerator<T> implements Enumeration<T> { |
| |
| |
| // ----------------------------------------------------------- Constructors |
| |
| |
| /** |
| * Return an Enumeration over the values returned by the |
| * specified Iterator. |
| * |
| * @param iterator Iterator to be wrapped |
| */ |
| public Enumerator(Iterator<T> iterator) { |
| |
| super(); |
| this.iterator = iterator; |
| |
| } |
| |
| |
| /** |
| * Return an Enumeration over the values returned by the |
| * specified Iterator. |
| * |
| * @param iterator Iterator to be wrapped |
| * @param clone true to clone iterator |
| */ |
| public Enumerator(Iterator<T> iterator, boolean clone) { |
| |
| super(); |
| if (!clone) { |
| this.iterator = iterator; |
| } else { |
| List<T> list = new ArrayList<T>(); |
| while (iterator.hasNext()) { |
| list.add(iterator.next()); |
| } |
| this.iterator = list.iterator(); |
| } |
| |
| } |
| |
| |
| // ----------------------------------------------------- Instance Variables |
| |
| |
| /** |
| * The <code>Iterator</code> over which the <code>Enumeration</code> |
| * represented by this class actually operates. |
| */ |
| private Iterator<T> iterator = null; |
| |
| |
| // --------------------------------------------------------- Public Methods |
| |
| |
| /** |
| * Tests if this enumeration contains more elements. |
| * |
| * @return <code>true</code> if and only if this enumeration object |
| * contains at least one more element to provide, <code>false</code> |
| * otherwise |
| */ |
| @Override |
| public boolean hasMoreElements() { |
| |
| return (iterator.hasNext()); |
| |
| } |
| |
| |
| /** |
| * Returns the next element of this enumeration if this enumeration |
| * has at least one more element to provide. |
| * |
| * @return the next element of this enumeration |
| * |
| * @exception NoSuchElementException if no more elements exist |
| */ |
| @Override |
| public T nextElement() throws NoSuchElementException { |
| |
| return (iterator.next()); |
| |
| } |
| |
| |
| } |