01: /*
02: * Licensed to the Apache Software Foundation (ASF) under one or more
03: * contributor license agreements. See the NOTICE file distributed with
04: * this work for additional information regarding copyright ownership.
05: * The ASF licenses this file to You under the Apache License, Version 2.0
06: * (the "License"); you may not use this file except in compliance with
07: * the License. You may obtain a copy of the License at
08: *
09: * 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:
21: /**
22: * Filters files based on size, can filter either smaller files or
23: * files equal to or larger than a given threshold.
24: * <p>
25: * For example, to print all files and directories in the
26: * current directory whose size is greater than 1 MB:
27: *
28: * <pre>
29: * File dir = new File(".");
30: * String[] files = dir.list( new SizeFileFilter(1024 * 1024) );
31: * for ( int i = 0; i < files.length; i++ ) {
32: * System.out.println(files[i]);
33: * }
34: * </pre>
35: *
36: * @author Rahul Akolkar
37: * @version $Id: SizeFileFilter.java 463570 2006-10-13 06:14:41Z niallp $
38: * @since Commons IO 1.2
39: */
40: public class SizeFileFilter extends AbstractFileFilter {
41:
42: /** The size threshold. */
43: private long size;
44: /** Whether the files accepted will be larger or smaller. */
45: private boolean acceptLarger;
46:
47: /**
48: * Constructs a new size file filter for files equal to or
49: * larger than a certain size.
50: *
51: * @param size the threshold size of the files
52: * @throws IllegalArgumentException if the size is negative
53: */
54: public SizeFileFilter(long size) {
55: this (size, true);
56: }
57:
58: /**
59: * Constructs a new size file filter for files based on a certain size
60: * threshold.
61: *
62: * @param size the threshold size of the files
63: * @param acceptLarger if true, files equal to or larger are accepted,
64: * otherwise smaller ones (but not equal to)
65: * @throws IllegalArgumentException if the size is negative
66: */
67: public SizeFileFilter(long size, boolean acceptLarger) {
68: if (size < 0) {
69: throw new IllegalArgumentException(
70: "The size must be non-negative");
71: }
72: this .size = size;
73: this .acceptLarger = acceptLarger;
74: }
75:
76: //-----------------------------------------------------------------------
77: /**
78: * Checks to see if the size of the file is favorable.
79: * <p>
80: * If size equals threshold and smaller files are required,
81: * file <b>IS NOT</b> selected.
82: * If size equals threshold and larger files are required,
83: * file <b>IS</b> selected.
84: *
85: * @param file the File to check
86: * @return true if the filename matches
87: */
88: public boolean accept(File file) {
89: boolean smaller = file.length() < size;
90: return acceptLarger ? !smaller : smaller;
91: }
92:
93: }
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