01: /*
02: * Copyright 2003-2004 The Apache Software Foundation
03: *
04: * Licensed under the Apache License, Version 2.0 (the "License");
05: * you may not use this file except in compliance with the License.
06: * You may obtain a copy of the License at
07: *
08: * http://www.apache.org/licenses/LICENSE-2.0
09: *
10: * Unless required by applicable law or agreed to in writing, software
11: * distributed under the License is distributed on an "AS IS" BASIS,
12: * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13: * See the License for the specific language governing permissions and
14: * limitations under the License.
15: */
16: package org.apache.commons.collections.bag;
17:
18: import org.apache.commons.collections.SortedBag;
19: import org.apache.commons.collections.functors.InstanceofPredicate;
20:
21: /**
22: * Decorates another <code>SortedBag</code> to validate that elements added
23: * are of a specific type.
24: * <p>
25: * The validation of additions is performed via an instanceof test against
26: * a specified <code>Class</code>. If an object cannot be added to the
27: * collection, an IllegalArgumentException is thrown.
28: *
29: * @since Commons Collections 3.0
30: * @version $Revision: 155406 $ $Date: 2005-02-26 12:55:26 +0000 (Sat, 26 Feb 2005) $
31: *
32: * @author Stephen Colebourne
33: * @author Matthew Hawthorne
34: */
35: public class TypedSortedBag {
36:
37: /**
38: * Factory method to create a typed sorted bag.
39: * <p>
40: * If there are any elements already in the bag being decorated, they
41: * are validated.
42: *
43: * @param bag the bag to decorate, must not be null
44: * @param type the type to allow into the bag, must not be null
45: * @return a new transformed SortedBag
46: * @throws IllegalArgumentException if bag or type is null
47: * @throws IllegalArgumentException if the bag contains invalid elements
48: */
49: public static SortedBag decorate(SortedBag bag, Class type) {
50: return new PredicatedSortedBag(bag, InstanceofPredicate
51: .getInstance(type));
52: }
53:
54: /**
55: * Restrictive constructor.
56: */
57: protected TypedSortedBag() {
58: super();
59: }
60:
61: }
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