01: /*
02: * Copyright 2001-2005 Sun Microsystems, Inc. All Rights Reserved.
03: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
04: *
05: * This code is free software; you can redistribute it and/or modify it
06: * under the terms of the GNU General Public License version 2 only, as
07: * published by the Free Software Foundation. Sun designates this
08: * particular file as subject to the "Classpath" exception as provided
09: * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22: * CA 95054 USA or visit www.sun.com if you need additional information or
23: * have any 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: */
49: public ResourceBundleEnumeration(Set<String> set,
50: Enumeration<String> enumeration) {
51: this .set = set;
52: this .iterator = set.iterator();
53: this .enumeration = enumeration;
54: }
55:
56: String next = null;
57:
58: public boolean hasMoreElements() {
59: if (next == null) {
60: if (iterator.hasNext()) {
61: next = iterator.next();
62: } else if (enumeration != null) {
63: while (next == null && enumeration.hasMoreElements()) {
64: next = enumeration.nextElement();
65: if (set.contains(next)) {
66: next = null;
67: }
68: }
69: }
70: }
71: return next != null;
72: }
73:
74: public String nextElement() {
75: if (hasMoreElements()) {
76: String result = next;
77: next = null;
78: return result;
79: } else {
80: throw new NoSuchElementException();
81: }
82: }
83: }
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