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; 021import java.nio.file.FileVisitResult; 022import java.nio.file.Path; 023import java.nio.file.attribute.BasicFileAttributes; 024 025/** 026 * A file filter that always returns false. 027 * <h2>Deprecating Serialization</h2> 028 * <p> 029 * <em>Serialization is deprecated and will be removed in 3.0.</em> 030 * </p> 031 * 032 * @since 1.0 033 * @see FileFilterUtils#falseFileFilter() 034 */ 035public class FalseFileFilter implements IOFileFilter, Serializable { 036 037 private static final String TO_STRING = Boolean.FALSE.toString(); 038 039 /** 040 * Singleton instance of false filter. 041 * 042 * @since 1.3 043 */ 044 public static final IOFileFilter FALSE = new FalseFileFilter(); 045 046 /** 047 * Singleton instance of false filter. Please use the identical FalseFileFilter.FALSE constant. The new name is more 048 * JDK 1.5 friendly as it doesn't clash with other values when using static imports. 049 */ 050 public static final IOFileFilter INSTANCE = FALSE; 051 052 private static final long serialVersionUID = 6210271677940926200L; 053 054 /** 055 * Restrictive constructor. 056 */ 057 protected FalseFileFilter() { 058 } 059 060 /** 061 * Returns false. 062 * 063 * @param file the file to check (ignored) 064 * @return false 065 */ 066 @Override 067 public boolean accept(final File file) { 068 return false; 069 } 070 071 /** 072 * Returns false. 073 * 074 * @param dir the directory to check (ignored) 075 * @param name the file name (ignored) 076 * @return false 077 */ 078 @Override 079 public boolean accept(final File dir, final String name) { 080 return false; 081 } 082 083 /** 084 * Returns false. 085 * 086 * @param file the file to check (ignored) 087 * 088 * @return false 089 * @since 2.9.0 090 */ 091 @Override 092 public FileVisitResult accept(final Path file, final BasicFileAttributes attributes) { 093 return FileVisitResult.TERMINATE; 094 } 095 096 @Override 097 public IOFileFilter and(final IOFileFilter fileFilter) { 098 // FALSE AND expression <=> FALSE 099 return INSTANCE; 100 } 101 102 @Override 103 public IOFileFilter negate() { 104 return TrueFileFilter.INSTANCE; 105 } 106 107 @Override 108 public IOFileFilter or(final IOFileFilter fileFilter) { 109 // FALSE OR expression <=> expression 110 return fileFilter; 111 } 112 113 @Override 114 public String toString() { 115 return TO_STRING; 116 } 117}