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.Closure;
22 import org.apache.commons.collections4.Transformer;
23
24 /**
25 * Closure implementation that calls a Transformer using the input object
26 * and ignore the result.
27 *
28 * @since 3.0
29 */
30 public class TransformerClosure<E> implements Closure<E>, Serializable {
31
32 /** Serial version UID */
33 private static final long serialVersionUID = -5194992589193388969L;
34
35 /**
36 * Factory method that performs validation.
37 * <p>
38 * A null transformer will return the {@code NOPClosure}.
39 *
40 * @param <E> the type that the closure acts on
41 * @param transformer the transformer to call, null means nop
42 * @return the {@code transformer} closure
43 */
44 public static <E> Closure<E> transformerClosure(final Transformer<? super E, ?> transformer) {
45 if (transformer == null) {
46 return NOPClosure.<E>nopClosure();
47 }
48 return new TransformerClosure<>(transformer);
49 }
50
51 /** The transformer to wrap */
52 private final Transformer<? super E, ?> iTransformer;
53
54 /**
55 * Constructor that performs no validation.
56 * Use {@code transformerClosure} if you want that.
57 *
58 * @param transformer the transformer to call, not null
59 */
60 public TransformerClosure(final Transformer<? super E, ?> transformer) {
61 iTransformer = transformer;
62 }
63
64 /**
65 * Executes the closure by calling the decorated transformer.
66 *
67 * @param input the input object
68 */
69 @Override
70 public void execute(final E input) {
71 iTransformer.transform(input);
72 }
73
74 /**
75 * Gets the transformer.
76 *
77 * @return the transformer
78 * @since 3.1
79 */
80 public Transformer<? super E, ?> getTransformer() {
81 return iTransformer;
82 }
83
84 }