    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     */
    017    package org.apache.commons.io.filefilter;
    018
    019    import java.io.File;
    020    import 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 Commons IO 1.3
    053     * @version $Revision: 659817 $
    054     */
    055    public class CanWriteFileFilter extends AbstractFileFilter implements Serializable {
    056
    057        /** Singleton instance of <i>writable</i> filter */
    058        public static final IOFileFilter CAN_WRITE = new CanWriteFileFilter();
    059
    060        /** Singleton instance of not <i>writable</i> filter */
    061        public static final IOFileFilter CANNOT_WRITE = new NotFileFilter(CAN_WRITE);
    062
    063        /**
    064         * Restrictive consructor.
    065         */
    066        protected CanWriteFileFilter() {
    067        }
    068
    069        /**
    070         * Checks to see if the file can be written to.
    071         *
    072         * @param file  the File to check
    073         * @return <code>true</code> if the file can be
    074         *  written to, otherwise <code>false</code>.
    075         */
    076        @Override
    077        public boolean accept(File file) {
    078            return file.canWrite();
    079        }
    080
    081    }