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.io.filefilter;
018
019import java.io.File;
020import java.io.Serializable;
021import java.nio.file.FileVisitResult;
022import java.nio.file.Files;
023import java.nio.file.Path;
024import java.nio.file.attribute.BasicFileAttributes;
025
026/**
027 * This filter accepts {@link File}s that can be executed.
028 * <p>
029 * Example, showing how to print out a list of the
030 * current directory's <i>executable</i> files:
031 * </p>
032 * <h2>Using Classic IO</h2>
033 * <pre>
034 * File dir = FileUtils.current();
035 * String[] files = dir.list(CanExecuteFileFilter.CAN_EXECUTE);
036 * for (String file : files) {
037 *     System.out.println(file);
038 * }
039 * </pre>
040 *
041 * <p>
042 * Example, showing how to print out a list of the
043 * current directory's <i>non-executable</i> files:
044 * </p>
045 *
046 * <pre>
047 * File dir = FileUtils.current();
048 * String[] files = dir.list(CanExecuteFileFilter.CANNOT_EXECUTE);
049 * for (int i = 0; i &lt; files.length; i++) {
050 *     System.out.println(files[i]);
051 * }
052 * </pre>
053 * <h2>Deprecating Serialization</h2>
054 * <p>
055 * <em>Serialization is deprecated and will be removed in 3.0.</em>
056 * </p>
057 *
058 * @since 2.7
059 */
060public class CanExecuteFileFilter extends AbstractFileFilter implements Serializable {
061
062    /** Singleton instance of <i>executable</i> filter */
063    public static final IOFileFilter CAN_EXECUTE = new CanExecuteFileFilter();
064
065    /** Singleton instance of not <i>executable</i> filter */
066    public static final IOFileFilter CANNOT_EXECUTE = CAN_EXECUTE.negate();
067
068    private static final long serialVersionUID = 3179904805251622989L;
069
070    /**
071     * Restrictive constructor.
072     */
073    protected CanExecuteFileFilter() {
074        // empty.
075    }
076
077    /**
078     * Checks to see if the file can be executed.
079     *
080     * @param file  the File to check.
081     * @return {@code true} if the file can be executed, otherwise {@code false}.
082     */
083    @Override
084    public boolean accept(final File file) {
085        return file.canExecute();
086    }
087
088    /**
089     * Checks to see if the file can be executed.
090     * @param file  the File to check.
091     *
092     * @return {@code true} if the file can be executed, otherwise {@code false}.
093     * @since 2.9.0
094     */
095    @Override
096    public FileVisitResult accept(final Path file, final BasicFileAttributes attributes) {
097        return toFileVisitResult(Files.isExecutable(file));
098    }
099
100}