    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;
    021
    022/**
    023 * This filter accepts <code>File</code>s that can be executed.
    024 * <p>
    025 * Example, showing how to print out a list of the
    026 * current directory's <i>executable</i> files:
    027 *
    028 * <pre>
    029 * File dir = new File(".");
    030 * String[] files = dir.list( CanExecuteFileFilter.CAN_EXECUTE );
    031 * for ( int i = 0; i &lt; files.length; i++ ) {
    032 *     System.out.println(files[i]);
    033 * }
    034 * </pre>
    035 *
    036 * <p>
    037 * Example, showing how to print out a list of the
    038 * current directory's <i>un-executable</i> files:
    039 *
    040 * <pre>
    041 * File dir = new File(".");
    042 * String[] files = dir.list( CanExecuteFileFilter.CANNOT_EXECUTE );
    043 * for ( int i = 0; i &lt; files.length; i++ ) {
    044 *     System.out.println(files[i]);
    045 * }
    046 * </pre>
    047 *
    048 * @since 2.7
    049 *
    050 */
    051public class CanExecuteFileFilter extends AbstractFileFilter implements Serializable {
    052
    053    private static final long serialVersionUID = 3179904805251622989L;
    054
    055    /** Singleton instance of <i>executable</i> filter */
    056    public static final IOFileFilter CAN_EXECUTE = new CanExecuteFileFilter();
    057
    058    /** Singleton instance of not <i>executable</i> filter */
    059    public static final IOFileFilter CANNOT_EXECUTE = new NotFileFilter(CAN_EXECUTE);
    060
    061    /**
    062     * Restrictive constructor.
    063     */
    064    protected CanExecuteFileFilter() {
    065    }
    066
    067    /**
    068     * Checks to see if the file can be executed.
    069     *
    070     * @param file  the File to check.
    071     * @return {@code true} if the file can be executed, otherwise {@code false}.
    072     */
    073    @Override
    074    public boolean accept(final File file) {
    075        return file.canExecute();
    076    }
    077
    078}