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}