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; 021 022/** 023 * Filters files based on size, can filter either smaller files or 024 * files equal to or larger than a given threshold. 025 * <p> 026 * For example, to print all files and directories in the 027 * current directory whose size is greater than 1 MB: 028 * 029 * <pre> 030 * File dir = new File("."); 031 * String[] files = dir.list( new SizeFileFilter(1024 * 1024) ); 032 * for ( int i = 0; i < files.length; i++ ) { 033 * System.out.println(files[i]); 034 * } 035 * </pre> 036 * 037 * @since 1.2 038 * @see FileFilterUtils#sizeFileFilter(long) 039 * @see FileFilterUtils#sizeFileFilter(long, boolean) 040 * @see FileFilterUtils#sizeRangeFileFilter(long, long) 041 */ 042public class SizeFileFilter extends AbstractFileFilter implements Serializable { 043 044 private static final long serialVersionUID = 7388077430788600069L; 045 046 /** The size threshold. */ 047 private final long size; 048 049 /** Whether the files accepted will be larger or smaller. */ 050 private final boolean acceptLarger; 051 052 /** 053 * Constructs a new size file filter for files equal to or 054 * larger than a certain size. 055 * 056 * @param size the threshold size of the files 057 * @throws IllegalArgumentException if the size is negative 058 */ 059 public SizeFileFilter(final long size) { 060 this(size, true); 061 } 062 063 /** 064 * Constructs a new size file filter for files based on a certain size 065 * threshold. 066 * 067 * @param size the threshold size of the files 068 * @param acceptLarger if true, files equal to or larger are accepted, 069 * otherwise smaller ones (but not equal to) 070 * @throws IllegalArgumentException if the size is negative 071 */ 072 public SizeFileFilter(final long size, final boolean acceptLarger) { 073 if (size < 0) { 074 throw new IllegalArgumentException("The size must be non-negative"); 075 } 076 this.size = size; 077 this.acceptLarger = acceptLarger; 078 } 079 080 /** 081 * Checks to see if the size of the file is favorable. 082 * <p> 083 * If size equals threshold and smaller files are required, 084 * file <b>IS NOT</b> selected. 085 * If size equals threshold and larger files are required, 086 * file <b>IS</b> selected. 087 * </p> 088 * 089 * @param file the File to check 090 * @return true if the file name matches 091 */ 092 @Override 093 public boolean accept(final File file) { 094 return acceptLarger != file.length() < size; 095 } 096 097 /** 098 * Provide a String representation of this file filter. 099 * 100 * @return a String representation 101 */ 102 @Override 103 public String toString() { 104 final String condition = acceptLarger ? ">=" : "<"; 105 return super.toString() + "(" + condition + size + ")"; 106 } 107 108}