    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}