    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 written to.
    028 * <p>
    029 * Example, showing how to print out a list of the current directory's <em>writable</em> files:
    030 * </p>
    031 * <h2>Using Classic IO</h2>
    032 * <pre>
    033 * File dir = FileUtils.current();
    034 * String[] files = dir.list(CanWriteFileFilter.CAN_WRITE);
    035 * for (String file : files) {
    036 *     System.out.println(file);
    037 * }
    038 * </pre>
    039 * <p>
    040 * Example, showing how to print out a list of the current directory's <em>un-writable</em> files:
    041 * </p>
    042 * <pre>
    043 * File dir = FileUtils.current();
    044 * String[] files = dir.list(CanWriteFileFilter.CANNOT_WRITE);
    045 * for (String file : files) {
    046 *     System.out.println(file);
    047 * }
    048 * </pre>
    049 * <p>
    050 * <strong>N.B.</strong> For read-only files, use {@code CanReadFileFilter.READ_ONLY}.
    051 * </p>
    052 * <h2>Deprecating Serialization</h2>
    053 * <p>
    054 * <em>Serialization is deprecated and will be removed in 3.0.</em>
    055 * </p>
    056 *
    057 * @since 1.3
    058 */
    059public class CanWriteFileFilter extends AbstractFileFilter implements Serializable {
    060
    061    /** Singleton instance of <em>writable</em> filter */
    062    public static final IOFileFilter CAN_WRITE = new CanWriteFileFilter();
    063
    064    /** Singleton instance of not <em>writable</em> filter */
    065    public static final IOFileFilter CANNOT_WRITE = CAN_WRITE.negate();
    066
    067    private static final long serialVersionUID = 5132005214688990379L;
    068
    069    /**
    070     * Restrictive constructor.
    071     */
    072    protected CanWriteFileFilter() {
    073    }
    074
    075    /**
    076     * Checks to see if the file can be written to.
    077     *
    078     * @param file the File to check
    079     * @return {@code true} if the file can be written to, otherwise {@code false}.
    080     */
    081    @Override
    082    public boolean accept(final File file) {
    083        return file != null && file.canWrite();
    084    }
    085
    086    /**
    087     * Checks to see if the file can be written to.
    088     *
    089     * @param file the File to check
    090     * @param attributes the path's basic attributes (may be null).
    091     * @return {@code true} if the file can be written to, otherwise {@code false}.
    092     * @since 2.9.0
    093     */
    094    @Override
    095    public FileVisitResult accept(final Path file, final BasicFileAttributes attributes) {
    096        return toFileVisitResult(file != null && Files.isWritable(file));
    097    }
    098
    099}