01: /*
02: * @(#)CompoundEnumeration.java 1.11 06/10/10
03: *
04: * Copyright 1990-2006 Sun Microsystems, Inc. All Rights Reserved.
05: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
06: *
07: * This program is free software; you can redistribute it and/or
08: * modify it under the terms of the GNU General Public License version
09: * 2 only, as published by the Free Software Foundation.
10: *
11: * This program is distributed in the hope that it will be useful, but
12: * WITHOUT ANY WARRANTY; without even the implied warranty of
13: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14: * General Public License version 2 for more details (a copy is
15: * included at /legal/license.txt).
16: *
17: * You should have received a copy of the GNU General Public License
18: * version 2 along with this work; if not, write to the Free Software
19: * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
20: * 02110-1301 USA
21: *
22: * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
23: * Clara, CA 95054 or visit www.sun.com if you need additional
24: * information or have any questions.
25: *
26: */
27:
28: package sun.misc;
29:
30: import java.util.Enumeration;
31: import java.util.NoSuchElementException;
32:
33: /*
34: * A useful utility class that will enumerate over an array of
35: * enumerations.
36: */
37: public class CompoundEnumeration implements Enumeration {
38: private Enumeration[] enums;
39: private int index = 0;
40:
41: public CompoundEnumeration(Enumeration[] enums) {
42: this .enums = enums;
43: }
44:
45: private boolean next() {
46: while (index < enums.length) {
47: if (enums[index] != null && enums[index].hasMoreElements()) {
48: return true;
49: }
50: index++;
51: }
52: return false;
53: }
54:
55: public boolean hasMoreElements() {
56: return next();
57: }
58:
59: public Object nextElement() {
60: if (!next()) {
61: throw new NoSuchElementException();
62: }
63: return enums[index].nextElement();
64: }
65: }
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