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