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 org.apache.commons.collections4.Closure;
20
21 /**
22 * Closure implementation that calls another closure n times, like a for loop.
23 * <p>
24 * <strong>WARNING:</strong> from v4.1 onwards this class will <strong>not</strong> be serializable anymore
25 * in order to prevent potential remote code execution exploits. Please refer to
26 * <a href="https://issues.apache.org/jira/browse/COLLECTIONS-580">COLLECTIONS-580</a>
27 * for more details.
28 * </p>
29 *
30 * @param <T> the type of the input to the operation.
31 * @since 3.0
32 */
33 public class ForClosure<T> implements Closure<T> {
34
35 /**
36 * Factory method that performs validation.
37 * <p>
38 * A null closure or zero count returns the {@code NOPClosure}.
39 * A count of one returns the specified closure.
40 *
41 * @param <E> the type that the closure acts on
42 * @param count the number of times to execute the closure
43 * @param closure the closure to execute, not null
44 * @return the {@code for} closure
45 */
46 @SuppressWarnings("unchecked")
47 public static <E> Closure<E> forClosure(final int count, final Closure<? super E> closure) {
48 if (count <= 0 || closure == null) {
49 return NOPClosure.<E>nopClosure();
50 }
51 if (count == 1) {
52 return (Closure<E>) closure;
53 }
54 return new ForClosure<>(count, closure);
55 }
56 /** The number of times to loop */
57 private final int iCount;
58
59 /** The closure to call */
60 private final Closure<? super T> iClosure;
61
62 /**
63 * Constructor that performs no validation.
64 * Use {@code forClosure} if you want that.
65 *
66 * @param count the number of times to execute the closure
67 * @param closure the closure to execute, not null
68 */
69 public ForClosure(final int count, final Closure<? super T> closure) {
70 iCount = count;
71 iClosure = closure;
72 }
73
74 /**
75 * Executes the closure {@code count} times.
76 *
77 * @param input the input object
78 */
79 @Override
80 public void execute(final T input) {
81 for (int i = 0; i < iCount; i++) {
82 iClosure.accept(input);
83 }
84 }
85
86 /**
87 * Gets the closure.
88 *
89 * @return the closure
90 * @since 3.1
91 */
92 public Closure<? super T> getClosure() {
93 return iClosure;
94 }
95
96 /**
97 * Gets the count.
98 *
99 * @return the count
100 * @since 3.1
101 */
102 public int getCount() {
103 return iCount;
104 }
105
106 }