001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      https://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.collections4.functors;
018
019import org.apache.commons.collections4.Closure;
020
021/**
022 * Closure implementation that calls another closure n times, like a for loop.
023 * <p>
024 * <strong>WARNING:</strong> from v4.1 onwards this class will <strong>not</strong> be serializable anymore
025 * in order to prevent potential remote code execution exploits. Please refer to
026 * <a href="https://issues.apache.org/jira/browse/COLLECTIONS-580">COLLECTIONS-580</a>
027 * for more details.
028 * </p>
029 *
030 * @param <T> The type of the input to the operation.
031 * @since 3.0
032 */
033public class ForClosure<T> implements Closure<T> {
034
035    /**
036     * Factory method that performs validation.
037     * <p>
038     * A null closure or zero count returns the {@code NOPClosure}.
039     * A count of one returns the specified closure.
040     * </p>
041     *
042     * @param <E> The type that the closure acts on
043     * @param count  The number of times to execute the closure
044     * @param closure  The closure to execute, not null
045     * @return The {@code for} closure
046     */
047    @SuppressWarnings("unchecked")
048    public static <E> Closure<E> forClosure(final int count, final Closure<? super E> closure) {
049        if (count <= 0 || closure == null) {
050            return NOPClosure.<E>nopClosure();
051        }
052        if (count == 1) {
053            return (Closure<E>) closure;
054        }
055        return new ForClosure<>(count, closure);
056    }
057
058    /** The number of times to loop */
059    private final int iCount;
060
061    /** The closure to call */
062    private final Closure<? super T> iClosure;
063
064    /**
065     * Constructor that performs no validation.
066     * Use {@code forClosure} if you want that.
067     *
068     * @param count  The number of times to execute the closure
069     * @param closure  The closure to execute, not null
070     */
071    public ForClosure(final int count, final Closure<? super T> closure) {
072        iCount = count;
073        iClosure = closure;
074    }
075
076    /**
077     * Executes the closure {@code count} times.
078     *
079     * @param input  The input object
080     */
081    @Override
082    public void execute(final T input) {
083        for (int i = 0; i < iCount; i++) {
084            iClosure.accept(input);
085        }
086    }
087
088    /**
089     * Gets the closure.
090     *
091     * @return The closure
092     * @since 3.1
093     */
094    public Closure<? super T> getClosure() {
095        return iClosure;
096    }
097
098    /**
099     * Gets the count.
100     *
101     * @return The count
102     * @since 3.1
103     */
104    public int getCount() {
105        return iCount;
106    }
107
108}