1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.collections4.functors;
18
19 import java.io.Serializable;
20
21 import org.apache.commons.collections4.Predicate;
22
23 /**
24 * Predicate implementation that returns true if the input is an instanceof
25 * the type stored in this predicate.
26 *
27 * @since 3.0
28 */
29 public final class InstanceofPredicate implements Predicate<Object>, Serializable {
30
31 /** Serial version UID */
32 private static final long serialVersionUID = -6682656911025165584L;
33
34 /** The type to compare to */
35 private final Class<?> iType;
36
37 /**
38 * Factory to create the identity predicate.
39 *
40 * @param type the type to check for, may not be null
41 * @return the predicate
42 * @throws NullPointerException if the class is null
43 */
44 public static Predicate<Object> instanceOfPredicate(final Class<?> type) {
45 if (type == null) {
46 throw new NullPointerException("The type to check instanceof must not be null");
47 }
48 return new InstanceofPredicate(type);
49 }
50
51 /**
52 * Constructor that performs no validation.
53 * Use <code>instanceOfPredicate</code> if you want that.
54 *
55 * @param type the type to check for
56 */
57 public InstanceofPredicate(final Class<?> type) {
58 super();
59 iType = type;
60 }
61
62 /**
63 * Evaluates the predicate returning true if the input object is of the correct type.
64 *
65 * @param object the input object
66 * @return true if input is of stored type
67 */
68 @Override
69 public boolean evaluate(final Object object) {
70 return iType.isInstance(object);
71 }
72
73 /**
74 * Gets the type to compare to.
75 *
76 * @return the type
77 * @since 3.1
78 */
79 public Class<?> getType() {
80 return iType;
81 }
82
83 }