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 1.3 049 * @version $Id: HiddenFileFilter.java 1304052 2012-03-22 20:55:29Z ggregory $ 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 }