| /* |
| * Copyright 1999,2004 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.catalina.util; |
| |
| |
| import java.util.Collection; |
| import java.util.Enumeration; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.ArrayList; |
| import java.util.Map; |
| 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 easliy create such wrappers. |
| * |
| * @author Craig R. McClanahan |
| * @version $Revision$ $Date$ |
| */ |
| |
| public final class Enumerator implements Enumeration { |
| |
| |
| // ----------------------------------------------------------- Constructors |
| |
| |
| /** |
| * Return an Enumeration over the values of the specified Collection. |
| * |
| * @param collection Collection whose values should be enumerated |
| */ |
| public Enumerator(Collection collection) { |
| |
| this(collection.iterator()); |
| |
| } |
| |
| |
| /** |
| * Return an Enumeration over the values of the specified Collection. |
| * |
| * @param collection Collection whose values should be enumerated |
| * @param clone true to clone iterator |
| */ |
| public Enumerator(Collection collection, boolean clone) { |
| |
| this(collection.iterator(), clone); |
| |
| } |
| |
| |
| /** |
| * Return an Enumeration over the values returned by the |
| * specified Iterator. |
| * |
| * @param iterator Iterator to be wrapped |
| */ |
| public Enumerator(Iterator 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 iterator, boolean clone) { |
| |
| super(); |
| if (!clone) { |
| this.iterator = iterator; |
| } else { |
| List list = new ArrayList(); |
| while (iterator.hasNext()) { |
| list.add(iterator.next()); |
| } |
| this.iterator = list.iterator(); |
| } |
| |
| } |
| |
| |
| /** |
| * Return an Enumeration over the values of the specified Map. |
| * |
| * @param map Map whose values should be enumerated |
| */ |
| public Enumerator(Map map) { |
| |
| this(map.values().iterator()); |
| |
| } |
| |
| |
| /** |
| * Return an Enumeration over the values of the specified Map. |
| * |
| * @param map Map whose values should be enumerated |
| * @param clone true to clone iterator |
| */ |
| public Enumerator(Map map, boolean clone) { |
| |
| this(map.values().iterator(), clone); |
| |
| } |
| |
| |
| // ----------------------------------------------------- Instance Variables |
| |
| |
| /** |
| * The <code>Iterator</code> over which the <code>Enumeration</code> |
| * represented by this class actually operates. |
| */ |
| private Iterator 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 |
| */ |
| 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 |
| */ |
| public Object nextElement() throws NoSuchElementException { |
| |
| return (iterator.next()); |
| |
| } |
| |
| |
| } |