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 /** The size threshold. */ 046 private final long size; 047 /** Whether the files accepted will be larger or smaller. */ 048 private final boolean acceptLarger; 049 050 /** 051 * Constructs a new size file filter for files equal to or 052 * larger than a certain size. 053 * 054 * @param size the threshold size of the files 055 * @throws IllegalArgumentException if the size is negative 056 */ 057 public SizeFileFilter(final long size) { 058 this(size, true); 059 } 060 061 /** 062 * Constructs a new size file filter for files based on a certain size 063 * threshold. 064 * 065 * @param size the threshold size of the files 066 * @param acceptLarger if true, files equal to or larger are accepted, 067 * otherwise smaller ones (but not equal to) 068 * @throws IllegalArgumentException if the size is negative 069 */ 070 public SizeFileFilter(final long size, final boolean acceptLarger) { 071 if (size < 0) { 072 throw new IllegalArgumentException("The size must be non-negative"); 073 } 074 this.size = size; 075 this.acceptLarger = acceptLarger; 076 } 077 078 //----------------------------------------------------------------------- 079 /** 080 * Checks to see if the size of the file is favorable. 081 * <p> 082 * If size equals threshold and smaller files are required, 083 * file <b>IS NOT</b> selected. 084 * If size equals threshold and larger files are required, 085 * file <b>IS</b> selected. 086 * 087 * @param file the File to check 088 * @return true if the file name matches 089 */ 090 @Override 091 public boolean accept(final File file) { 092 final boolean smaller = file.length() < size; 093 return acceptLarger != smaller; 094 } 095 096 /** 097 * Provide a String representation of this file filter. 098 * 099 * @return a String representation 100 */ 101 @Override 102 public String toString() { 103 final String condition = acceptLarger ? ">=" : "<"; 104 return super.toString() + "(" + condition + size + ")"; 105 } 106 107}