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 *      http://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 * <b>WARNING:</b> from v4.1 onwards this class will <b>not</b> 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 * @since 3.0
031 */
032public class ForClosure<E> implements Closure<E> {
033
034    /**
035     * Factory method that performs validation.
036     * <p>
037     * A null closure or zero count returns the {@code NOPClosure}.
038     * A count of one returns the specified closure.
039     *
040     * @param <E> the type that the closure acts on
041     * @param count  the number of times to execute the closure
042     * @param closure  the closure to execute, not null
043     * @return the {@code for} closure
044     */
045    @SuppressWarnings("unchecked")
046    public static <E> Closure<E> forClosure(final int count, final Closure<? super E> closure) {
047        if (count <= 0 || closure == null) {
048            return NOPClosure.<E>nopClosure();
049        }
050        if (count == 1) {
051            return (Closure<E>) closure;
052        }
053        return new ForClosure<>(count, closure);
054    }
055    /** The number of times to loop */
056    private final int iCount;
057
058    /** The closure to call */
059    private final Closure<? super E> iClosure;
060
061    /**
062     * Constructor that performs no validation.
063     * Use {@code forClosure} if you want that.
064     *
065     * @param count  the number of times to execute the closure
066     * @param closure  the closure to execute, not null
067     */
068    public ForClosure(final int count, final Closure<? super E> closure) {
069        iCount = count;
070        iClosure = closure;
071    }
072
073    /**
074     * Executes the closure {@code count} times.
075     *
076     * @param input  the input object
077     */
078    @Override
079    public void execute(final E input) {
080        for (int i = 0; i < iCount; i++) {
081            iClosure.execute(input);
082        }
083    }
084
085    /**
086     * Gets the closure.
087     *
088     * @return the closure
089     * @since 3.1
090     */
091    public Closure<? super E> getClosure() {
092        return iClosure;
093    }
094
095    /**
096     * Gets the count.
097     *
098     * @return the count
099     * @since 3.1
100     */
101    public int getCount() {
102        return iCount;
103    }
104
105}