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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  }