1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.io.filefilter;
18
19 import java.io.File;
20 import java.io.Serializable;
21
22 /**
23 * Filters files based on size, can filter either smaller files or
24 * files equal to or larger than a given threshold.
25 * <p>
26 * For example, to print all files and directories in the
27 * current directory whose size is greater than 1 MB:
28 *
29 * <pre>
30 * File dir = new File(".");
31 * String[] files = dir.list( new SizeFileFilter(1024 * 1024) );
32 * for ( int i = 0; i < files.length; i++ ) {
33 * System.out.println(files[i]);
34 * }
35 * </pre>
36 *
37 * @version $Id: SizeFileFilter.java 1415850 2012-11-30 20:51:39Z ggregory $
38 * @since 1.2
39 * @see FileFilterUtils#sizeFileFilter(long)
40 * @see FileFilterUtils#sizeFileFilter(long, boolean)
41 * @see FileFilterUtils#sizeRangeFileFilter(long, long)
42 */
43 public class SizeFileFilter extends AbstractFileFilter implements Serializable {
44
45 /** The size threshold. */
46 private final long size;
47 /** Whether the files accepted will be larger or smaller. */
48 private final boolean acceptLarger;
49
50 /**
51 * Constructs a new size file filter for files equal to or
52 * larger than a certain size.
53 *
54 * @param size the threshold size of the files
55 * @throws IllegalArgumentException if the size is negative
56 */
57 public SizeFileFilter(final long size) {
58 this(size, true);
59 }
60
61 /**
62 * Constructs a new size file filter for files based on a certain size
63 * threshold.
64 *
65 * @param size the threshold size of the files
66 * @param acceptLarger if true, files equal to or larger are accepted,
67 * otherwise smaller ones (but not equal to)
68 * @throws IllegalArgumentException if the size is negative
69 */
70 public SizeFileFilter(final long size, final boolean acceptLarger) {
71 if (size < 0) {
72 throw new IllegalArgumentException("The size must be non-negative");
73 }
74 this.size = size;
75 this.acceptLarger = acceptLarger;
76 }
77
78 //-----------------------------------------------------------------------
79 /**
80 * Checks to see if the size of the file is favorable.
81 * <p>
82 * If size equals threshold and smaller files are required,
83 * file <b>IS NOT</b> selected.
84 * If size equals threshold and larger files are required,
85 * file <b>IS</b> selected.
86 *
87 * @param file the File to check
88 * @return true if the filename matches
89 */
90 @Override
91 public boolean accept(final File file) {
92 final boolean smaller = file.length() < size;
93 return acceptLarger ? !smaller : smaller;
94 }
95
96 /**
97 * Provide a String representaion of this file filter.
98 *
99 * @return a String representaion
100 */
101 @Override
102 public String toString() {
103 final String condition = acceptLarger ? ">=" : "<";
104 return super.toString() + "(" + condition + size + ")";
105 }
106
107 }