1 /*
2 * JDiskCatalog
3 *
4 * Copyright 2007 Przemek Więch
5 *
6 * This file is part of JDiskCatalog.
7 *
8 * JDiskCatalog is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23 package net.sf.jdiskcatalog.analysis;
24
25 import java.io.IOException;
26 import java.io.InputStream;
27 import java.util.HashMap;
28 import java.util.Map;
29 import java.util.zip.CRC32;
30
31 import net.sf.jdiskcatalog.api.NodeInfo;
32 import net.sf.jdiskcatalog.api.StreamAnalyser;
33
34
35 /**
36 * Calculates CRC for the given binary content.
37 *
38 * @author Przemek Więch <pwiech@losthive.org>
39 * @version $Id$
40 */
41 public class CrcAnalyser implements StreamAnalyser
42 {
43 public static final String KEY_CRC = "crc";
44
45 public Map<String, Object> analyse(InputStream stream, NodeInfo nodeInfo) throws IOException
46 {
47 Map<String, Object> properties = new HashMap<String, Object>();
48
49 CRC32 crc = new CRC32();
50 int b = stream.read();
51 while (b != -1)
52 {
53 crc.update(b);
54 b = stream.read();
55 }
56
57 properties.put(KEY_CRC, crc.getValue());
58 return properties;
59 }
60 }