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