    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 written to.
    024 * <p>
    025 * Example, showing how to print out a list of the
    026 * current directory's <i>writable</i> files:
    027 *
    028 * <pre>
    029 * File dir = new File(".");
    030 * String[] files = dir.list( CanWriteFileFilter.CAN_WRITE );
    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-writable</i> files:
    039 *
    040 * <pre>
    041 * File dir = new File(".");
    042 * String[] files = dir.list( CanWriteFileFilter.CANNOT_WRITE );
    043 * for ( int i = 0; i &lt; files.length; i++ ) {
    044 *     System.out.println(files[i]);
    045 * }
    046 * </pre>
    047 *
    048 * <p>
    049 * <b>N.B.</b> For read-only files, use
    050 *    <code>CanReadFileFilter.READ_ONLY</code>.
    051 *
    052 * @since 1.3
    053 *
    054 */
    055public class CanWriteFileFilter extends AbstractFileFilter implements Serializable {
    056
    057    private static final long serialVersionUID = 5132005214688990379L;
    058
    059    /** Singleton instance of <i>writable</i> filter */
    060    public static final IOFileFilter CAN_WRITE = new CanWriteFileFilter();
    061
    062    /** Singleton instance of not <i>writable</i> filter */
    063    public static final IOFileFilter CANNOT_WRITE = new NotFileFilter(CAN_WRITE);
    064
    065    /**
    066     * Restrictive constructor.
    067     */
    068    protected CanWriteFileFilter() {
    069    }
    070
    071    /**
    072     * Checks to see if the file can be written to.
    073     *
    074     * @param file  the File to check
    075     * @return {@code true} if the file can be
    076     *  written to, otherwise {@code false}.
    077     */
    078    @Override
    079    public boolean accept(final File file) {
    080        return file.canWrite();
    081    }
    082
    083}