01: /*
02: * <copyright>
03: *
04: * Copyright 1997-2004 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.util;
27:
28: import java.util.Iterator;
29:
30: /**
31: * Wraps an Enumeration and allows elements satisfying a UnaryPredicate to get through
32: **/
33: public class FilteredIterator implements Iterator {
34: private UnaryPredicate predicate;
35: private Iterator base;
36: private Object next = null;
37:
38: public FilteredIterator(Iterator iter, UnaryPredicate pred) {
39: base = iter;
40: predicate = pred;
41: }
42:
43: public boolean hasNext() {
44: while (next == null && base.hasNext()) {
45: next = base.next();
46: if (predicate.execute(next))
47: return true;
48: next = null;
49: }
50: return next != null;
51: }
52:
53: public Object next() {
54: if (next != null || hasNext()) {
55: Object result = next;
56: next = null;
57: return result;
58: }
59: throw new java.util.NoSuchElementException("Filtered Iterator");
60: }
61:
62: public void remove() {
63: base.remove();
64: }
65: }
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