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 are hidden.
024 * <p>
025 * Example, showing how to print out a list of the
026 * current directory's <i>hidden</i> files:
027 *
028 * <pre>
029 * File dir = new File(".");
030 * String[] files = dir.list( HiddenFileFilter.HIDDEN );
031 * for ( int i = 0; i < 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>visible</i> (i.e. not hidden) files:
039 *
040 * <pre>
041 * File dir = new File(".");
042 * String[] files = dir.list( HiddenFileFilter.VISIBLE );
043 * for ( int i = 0; i < files.length; i++ ) {
044 * System.out.println(files[i]);
045 * }
046 * </pre>
047 *
048 * @since Commons IO 1.3
049 * @version $Revision: 659817 $
050 */
051 public class HiddenFileFilter extends AbstractFileFilter implements Serializable {
052
053 /** Singleton instance of <i>hidden</i> filter */
054 public static final IOFileFilter HIDDEN = new HiddenFileFilter();
055
056 /** Singleton instance of <i>visible</i> filter */
057 public static final IOFileFilter VISIBLE = new NotFileFilter(HIDDEN);
058
059 /**
060 * Restrictive consructor.
061 */
062 protected HiddenFileFilter() {
063 }
064
065 /**
066 * Checks to see if the file is hidden.
067 *
068 * @param file the File to check
069 * @return <code>true</code> if the file is
070 * <i>hidden</i>, otherwise <code>false</code>.
071 */
072 @Override
073 public boolean accept(File file) {
074 return file.isHidden();
075 }
076
077 }