1 /* 2 * Copyright (c) 2001, 2005, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package sun.util; 27 28 import java.util.Enumeration; 29 import java.util.Iterator; 30 import java.util.NoSuchElementException; 31 import java.util.Set; 32 33 /** 34 * Implements an Enumeration that combines elements from a Set and 35 * an Enumeration. Used by ListResourceBundle and PropertyResourceBundle. 36 */ 37 public class ResourceBundleEnumeration implements Enumeration<String> { 38 39 Set<String> set; 40 Iterator<String> iterator; 41 Enumeration<String> enumeration; // may remain null 42 43 /** 44 * Constructs a resource bundle enumeration. 45 * @param set an set providing some elements of the enumeration 46 * @param enumeration an enumeration providing more elements of the enumeration. 47 * enumeration may be null. 48 */ ResourceBundleEnumeration(Set<String> set, Enumeration<String> enumeration)49 public ResourceBundleEnumeration(Set<String> set, Enumeration<String> enumeration) { 50 this.set = set; 51 this.iterator = set.iterator(); 52 this.enumeration = enumeration; 53 } 54 55 String next = null; 56 hasMoreElements()57 public boolean hasMoreElements() { 58 if (next == null) { 59 if (iterator.hasNext()) { 60 next = iterator.next(); 61 } else if (enumeration != null) { 62 while (next == null && enumeration.hasMoreElements()) { 63 next = enumeration.nextElement(); 64 if (set.contains(next)) { 65 next = null; 66 } 67 } 68 } 69 } 70 return next != null; 71 } 72 nextElement()73 public String nextElement() { 74 if (hasMoreElements()) { 75 String result = next; 76 next = null; 77 return result; 78 } else { 79 throw new NoSuchElementException(); 80 } 81 } 82 } 83