01:/*
02: * Copyright (c) 1998-2002 Carnegie Mellon University. All rights
03: * reserved.
04: *
05: * Redistribution and use in source and binary forms, with or without
06: * modification, are permitted provided that the following conditions
07: * are met:
08: *
09: * 1. Redistributions of source code must retain the above copyright
10: * notice, this list of conditions and the following disclaimer.
11: *
12: * 2. Redistributions in binary form must reproduce the above copyright
13: * notice, this list of conditions and the following disclaimer in
14: * the documentation and/or other materials provided with the
15: * distribution.
16: *
17: * THIS SOFTWARE IS PROVIDED BY CARNEGIE MELLON UNIVERSITY ``AS IS'' AND
18: * ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
19: * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
20: * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY
21: * NOR ITS EMPLOYEES BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27: * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28: *
29: */
30:
31:package rcm.enum;
32:import java.util.Enumeration;
33:import java.util.NoSuchElementException;
34:
35:/**
36: * Enumeration which transforms the elements of another enumeration.
37: */
38:public class ConcatEnumeration implements Enumeration {
39: Enumeration[] e;
40: int i = 0; // current enumeration in e
41:
42: public ConcatEnumeration (Enumeration e1, Enumeration e2) {
43: this .e = new Enumeration[] { e1, e2 };
44: }
45:
46: public ConcatEnumeration (Enumeration[] e) {
47: this .e = e;
48: }
49:
50: public boolean hasMoreElements () {
51: while (i < e.length) {
52: if (e[i].hasMoreElements ())
53: return true;
54: else
55: ++i;
56: }
57: return false;
58: }
59:
60: public Object nextElement () {
61: while (i < e.length) {
62: try {
63: return e[i].nextElement ();
64: } catch (NoSuchElementException e) {
65: ++i;
66: }
67: }
68:
69: throw new NoSuchElementException ();
70: }
71:}
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