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 */
017 package org.apache.commons.io.filefilter;
018
019 import java.io.File;
020 import 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 1304052 2012-03-22 20:55:29Z ggregory $
038 * @since 1.2
039 * @see FileFilterUtils#sizeFileFilter(long)
040 * @see FileFilterUtils#sizeFileFilter(long, boolean)
041 * @see FileFilterUtils#sizeRangeFileFilter(long, long)
042 */
043 public class SizeFileFilter extends AbstractFileFilter implements Serializable {
044
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(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(long size, 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 filename matches
089 */
090 @Override
091 public boolean accept(File file) {
092 boolean smaller = file.length() < size;
093 return acceptLarger ? !smaller : smaller;
094 }
095
096 /**
097 * Provide a String representaion of this file filter.
098 *
099 * @return a String representaion
100 */
101 @Override
102 public String toString() {
103 String condition = acceptLarger ? ">=" : "<";
104 return super.toString() + "(" + condition + size + ")";
105 }
106
107 }