1/* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17package org.apache.commons.io.filefilter; 18 19import java.io.File; 20import java.io.Serializable; 21 22/** 23 * This filter accepts <code>File</code>s that can be read. 24 * <p> 25 * Example, showing how to print out a list of the 26 * current directory's <i>readable</i> files: 27 * 28 * <pre> 29 * File dir = new File("."); 30 * String[] files = dir.list( CanReadFileFilter.CAN_READ ); 31 * for ( int i = 0; i < files.length; i++ ) { 32 * System.out.println(files[i]); 33 * } 34 * </pre> 35 * 36 * <p> 37 * Example, showing how to print out a list of the 38 * current directory's <i>un-readable</i> files: 39 * 40 * <pre> 41 * File dir = new File("."); 42 * String[] files = dir.list( CanReadFileFilter.CANNOT_READ ); 43 * for ( int i = 0; i < files.length; i++ ) { 44 * System.out.println(files[i]); 45 * } 46 * </pre> 47 * 48 * <p> 49 * Example, showing how to print out a list of the 50 * current directory's <i>read-only</i> files: 51 * 52 * <pre> 53 * File dir = new File("."); 54 * String[] files = dir.list( CanReadFileFilter.READ_ONLY ); 55 * for ( int i = 0; i < files.length; i++ ) { 56 * System.out.println(files[i]); 57 * } 58 * </pre> 59 * 60 * @since Commons IO 1.3 61 * @version $Revision: 587916 $ 62 */ 63public class CanReadFileFilter extends AbstractFileFilter implements Serializable { 64 65 /** Singleton instance of <i>readable</i> filter */ 66 public static final IOFileFilter CAN_READ = new CanReadFileFilter(); 67 68 /** Singleton instance of not <i>readable</i> filter */ 69 public static final IOFileFilter CANNOT_READ = new NotFileFilter(CAN_READ); 70 71 /** Singleton instance of <i>read-only</i> filter */ 72 public static final IOFileFilter READ_ONLY = new AndFileFilter(CAN_READ, 73 CanWriteFileFilter.CANNOT_WRITE); 74 75 /** 76 * Restrictive consructor. 77 */ 78 protected CanReadFileFilter() { 79 } 80 81 /** 82 * Checks to see if the file can be read. 83 * 84 * @param file the File to check. 85 * @return <code>true</code> if the file can be 86 * read, otherwise <code>false</code>. 87 */ 88 public boolean accept(File file) { 89 return file.canRead(); 90 } 91 92} 93