    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 *
    029 * @since 3.0
    030 */
    031public class ForClosure<E> implements Closure<E> {
    032
    033    /** The number of times to loop */
    034    private final int iCount;
    035    /** The closure to call */
    036    private final Closure<? super E> iClosure;
    037
    038    /**
    039     * Factory method that performs validation.
    040     * <p>
    041     * A null closure or zero count returns the <code>NOPClosure</code>.
    042     * A count of one returns the specified closure.
    043     *
    044     * @param <E> the type that the closure acts on
    045     * @param count  the number of times to execute the closure
    046     * @param closure  the closure to execute, not null
    047     * @return the <code>for</code> closure
    048     */
    049    @SuppressWarnings("unchecked")
    050    public static <E> Closure<E> forClosure(final int count, final Closure<? super E> closure) {
    051        if (count <= 0 || closure == null) {
    052            return NOPClosure.<E>nopClosure();
    053        }
    054        if (count == 1) {
    055            return (Closure<E>) closure;
    056        }
    057        return new ForClosure<>(count, closure);
    058    }
    059
    060    /**
    061     * Constructor that performs no validation.
    062     * Use <code>forClosure</code> if you want that.
    063     *
    064     * @param count  the number of times to execute the closure
    065     * @param closure  the closure to execute, not null
    066     */
    067    public ForClosure(final int count, final Closure<? super E> closure) {
    068        super();
    069        iCount = count;
    070        iClosure = closure;
    071    }
    072
    073    /**
    074     * Executes the closure <code>count</code> 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}