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Java > Open Source Codes > net > sf > jga > util > CollectionUtils


1 // ============================================================================
2 // $Id: CollectionUtils.java,v 1.1 2006/05/22 03:27:22 davidahall Exp $
3 // Copyright (c) 2006 David A. Hall
4 // ============================================================================
5 // The contents of this file are subject to the Common Development and
6 // Distribution License (CDDL), Version 1.0 (the License); you may not use this
7 // file except in compliance with the License. You should have received a copy
8 // of the the License along with this file: if not, a copy of the License is
9 // available from Sun Microsystems, Inc.
10 //
11 // http://www.sun.com/cddl/cddl.html
12 //
13 // From time to time, the license steward (initially Sun Microsystems, Inc.) may
14 // publish revised and/or new versions of the License. You may not use,
15 // distribute, or otherwise make this file available under subsequent versions
16 // of the License.
17 //
18 // Alternatively, the contents of this file may be used under the terms of the
19 // GNU Lesser General Public License Version 2.1 or later (the "LGPL"), in which
20 // case the provisions of the LGPL are applicable instead of those above. If you
21 // wish to allow use of your version of this file only under the terms of the
22 // LGPL, and not to allow others to use your version of this file under the
23 // terms of the CDDL, indicate your decision by deleting the provisions above
24 // and replace them with the notice and other provisions required by the LGPL.
25 // If you do not delete the provisions above, a recipient may use your version
26 // of this file under the terms of either the CDDL or the LGPL.
27 //
28 // This library is distributed in the hope that it will be useful,
29 // but WITHOUT ANY WARRANTY; without even the implied warranty of
30 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
31 // ============================================================================
32 package net.sf.jga.util;
33
34 import java.util.Collection JavaDoc;
35 import java.util.Iterator JavaDoc;
36
37 /**
38  * General utilites for working with collections. These are generally extensions
39  * to what's already defined in the standard java.util.Collection class
40  * <p>
41  * Copyright &copy; 2006 David A. Hall
42  *
43  * @author <a HREF="mailto:davidahall@users.sf.net">David A. Hall</a>
44  */
45
46 public class CollectionUtils {
47     /**
48      * Adds all of the elements of the iterator to the collection. If necessary and possible,
49      * the collection will be enlarged: if enlarging the collection is not possible, then a
50      * runtime exception will be thrown. This is an augmentation of the
51      * Collection.addAll(Collection) API method.
52      * @returns true if the state of the collection was changed.
53      */
54     static public <T> boolean addAll(Collection JavaDoc<? super T> cout, Iterator JavaDoc<T> iter) {
55         boolean b = false;
56         while(iter.hasNext()) {
57             b |= cout.add(iter.next());
58         }
59
60         return b;
61     }
62
63
64     /**
65      * Adds all of the arguments to the collection. If necessary and possible, the collection
66      * will be enlarged: if enlarging the collection is not possible, then a runtime exception
67      * will be thrown.
68      * Augmentation of the Collection.addAll(Collection) API method.
69      * @returns true if the state of the collection was changed.
70      */
71     static public <T> boolean addAll(Collection JavaDoc<? super T> cout, T... values) {
72         boolean b = false;
73         for(int i = 0; i < values.length; ++i) {
74             b |= cout.add(values[i]);
75         }
76
77         return b;
78     }
79     
80     /**
81      * Adds all of the elements of the iterator to the collection and returns the collection.
82      * If necessary and possible, the collection will be enlarged: if enlarging the collection
83      * is not possible, then a runtime exception is thrown.
84      */
85     static public <T,TCollection extends Collection JavaDoc<? super T>> TCollection
86     append(TCollection cout, Iterable JavaDoc<T> iterable)
87     {
88         addAll(cout, iterable.iterator());
89         return cout;
90     }
91
92
93     /**
94      * Adds all of the elements of the iterator to the collection and returns the collection.
95      * If necessary and possible, the collection will be enlarged: if enlarging the collection
96      * is not possible, then a runtime exception is thrown.
97      */
98     static public <T,TCollection extends Collection JavaDoc<? super T>> TCollection
99     append(TCollection cout, Iterator JavaDoc<T> iter)
100     {
101         addAll(cout, iter);
102         return cout;
103     }
104
105
106     /**
107      * Adds all of the arguments to the collection and returns the collection. If necessary
108      * and possible, the collection will be enlarged: if enlarging the collection is not
109      * possible, then the runtime exception thrown. A similar method exists in Java 1.5,
110      * although it returns boolean rather than the collection.
111      */
112     static public <T,TCollection extends Collection JavaDoc<? super T>> TCollection
113     append(TCollection cout, T... values)
114     {
115         addAll(cout, values);
116         return cout;
117     }
118 }
119
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