01: /*
02: * <copyright>
03: *
04: * Copyright 2003-2004 BBNT Solutions, LLC
05: * under sponsorship of the Defense Advanced Research Projects
06: * Agency (DARPA).
07: *
08: * You can redistribute this software and/or modify it under the
09: * terms of the Cougaar Open Source License as published on the
10: * Cougaar Open Source Website (www.cougaar.org).
11: *
12: * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
13: * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
14: * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
15: * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
16: * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
17: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
18: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
22: * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23: *
24: * </copyright>
25: */
26: package org.cougaar.logistics.plugin.seanet;
27:
28: import java.util.Iterator;
29:
30: /**
31: * A <code>SequenceIterator</code> iterates over the elements of two
32: * iterators in sequence.
33: *
34: * @see Iterator */
35: public class SequenceIterator implements Iterator {
36: Iterator a;
37: Iterator b;
38:
39: public SequenceIterator(Iterator a, Iterator b) {
40: this .a = a;
41: this .b = b;
42: }
43:
44: public boolean hasNext() {
45: if (a.hasNext()) {
46: return true;
47: } else if (b != null) {
48: a = b;
49: b = null;
50: return this .hasNext();
51: } else {
52: return false;
53: }
54: }
55:
56: public Object next() {
57: if (this .hasNext()) {
58: return a.next();
59: } else {
60: throw new java.util.NoSuchElementException();
61: }
62: }
63:
64: public void remove() {
65: throw new UnsupportedOperationException();
66: }
67: }
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