KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > jdom > FilterIterator


1 /*--
2
3  $Id: FilterIterator.java,v 1.5 2004/08/31 19:36:12 jhunter Exp $
4
5  Copyright (C) 2000-2004 Jason Hunter & Brett McLaughlin.
6  All rights reserved.
7
8  Redistribution and use in source and binary forms, with or without
9  modification, are permitted provided that the following conditions
10  are met:
11
12  1. Redistributions of source code must retain the above copyright
13     notice, this list of conditions, and the following disclaimer.
14
15  2. Redistributions in binary form must reproduce the above copyright
16     notice, this list of conditions, and the disclaimer that follows
17     these conditions in the documentation and/or other materials
18     provided with the distribution.
19
20  3. The name "JDOM" must not be used to endorse or promote products
21     derived from this software without prior written permission. For
22     written permission, please contact <request_AT_jdom_DOT_org>.
23
24  4. Products derived from this software may not be called "JDOM", nor
25     may "JDOM" appear in their name, without prior written permission
26     from the JDOM Project Management <request_AT_jdom_DOT_org>.
27
28  In addition, we request (but do not require) that you include in the
29  end-user documentation provided with the redistribution and/or in the
30  software itself an acknowledgement equivalent to the following:
31      "This product includes software developed by the
32       JDOM Project (http://www.jdom.org/)."
33  Alternatively, the acknowledgment may be graphical using the logos
34  available at http://www.jdom.org/images/logos.
35
36  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
37  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
38  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
39  DISCLAIMED. IN NO EVENT SHALL THE JDOM AUTHORS OR THE PROJECT
40  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
42  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
43  USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
44  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
45  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
46  OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
47  SUCH DAMAGE.
48
49  This software consists of voluntary contributions made by many
50  individuals on behalf of the JDOM Project and was originally
51  created by Jason Hunter <jhunter_AT_jdom_DOT_org> and
52  Brett McLaughlin <brett_AT_jdom_DOT_org>. For more information
53  on the JDOM Project, please see <http://www.jdom.org/>.
54
55  */
56
57 package org.jdom;
58
59 import java.util.*;
60 import org.jdom.filter.*;
61
62 /**
63  * Traverse a parent's children that match the supplied filter.
64  *
65  * @author Bradley S. Huffman
66  * @version $Revision: 1.5 $, $Date: 2004/08/31 19:36:12 $
67  */
68 class FilterIterator implements Iterator {
69
70     private Iterator iterator;
71     private Filter filter;
72     private Object JavaDoc nextObject;
73
74     private static final String JavaDoc CVS_ID =
75             "@(#) $RCSfile: FilterIterator.java,v $ $Revision: 1.5 $ $Date: 2004/08/31 19:36:12 $ $Name: $";
76
77     public FilterIterator(Iterator iterator, Filter filter) {
78         if ((iterator == null) || (filter == null)) {
79             throw new IllegalArgumentException JavaDoc("null parameter");
80         }
81         this.iterator = iterator;
82         this.filter = filter;
83     }
84
85     public boolean hasNext() {
86         if (nextObject != null) {
87             return true;
88         }
89
90         while (iterator.hasNext()) {
91             Object JavaDoc obj = iterator.next();
92             if (filter.matches(obj)) {
93                 nextObject = obj;
94                 return true;
95             }
96         }
97         return false;
98     }
99
100     public Object JavaDoc next() {
101         if (!hasNext()) {
102             throw new NoSuchElementException();
103         }
104
105         Object JavaDoc obj = nextObject;
106         nextObject = null;
107         return obj;
108     }
109
110     public void remove() {
111         // XXX Could cause probs for sure if hasNext() is
112 // called before the remove(), although that's unlikely.
113 iterator.remove();
114     }
115 }
116
Popular Tags