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 * @version $Id: SizeFileFilter.java 1642757 2014-12-01 21:09:30Z sebb $ 038 * @since 1.2 039 * @see FileFilterUtils#sizeFileFilter(long) 040 * @see FileFilterUtils#sizeFileFilter(long, boolean) 041 * @see FileFilterUtils#sizeRangeFileFilter(long, long) 042 */ 043public class SizeFileFilter extends AbstractFileFilter implements Serializable { 044 045 private static final long serialVersionUID = 7388077430788600069L; 046 /** The size threshold. */ 047 private final long size; 048 /** Whether the files accepted will be larger or smaller. */ 049 private final boolean acceptLarger; 050 051 /** 052 * Constructs a new size file filter for files equal to or 053 * larger than a certain size. 054 * 055 * @param size the threshold size of the files 056 * @throws IllegalArgumentException if the size is negative 057 */ 058 public SizeFileFilter(final long size) { 059 this(size, true); 060 } 061 062 /** 063 * Constructs a new size file filter for files based on a certain size 064 * threshold. 065 * 066 * @param size the threshold size of the files 067 * @param acceptLarger if true, files equal to or larger are accepted, 068 * otherwise smaller ones (but not equal to) 069 * @throws IllegalArgumentException if the size is negative 070 */ 071 public SizeFileFilter(final long size, final boolean acceptLarger) { 072 if (size < 0) { 073 throw new IllegalArgumentException("The size must be non-negative"); 074 } 075 this.size = size; 076 this.acceptLarger = acceptLarger; 077 } 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 * 088 * @param file the File to check 089 * @return true if the filename matches 090 */ 091 @Override 092 public boolean accept(final File file) { 093 final boolean smaller = file.length() < size; 094 return acceptLarger ? !smaller : smaller; 095 } 096 097 /** 098 * Provide a String representaion of this file filter. 099 * 100 * @return a String representaion 101 */ 102 @Override 103 public String toString() { 104 final String condition = acceptLarger ? ">=" : "<"; 105 return super.toString() + "(" + condition + size + ")"; 106 } 107 108}