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Java > Open Source Codes > org > archive > net > md5 > Handler


1 /* $Id: Handler.java,v 1.4 2006/08/31 16:51:41 stack-sf Exp $
2  *
3  * Created August 11th, 2006
4  *
5  * Copyright (C) 2006 Internet Archive.
6  *
7  * This file is part of the Heritrix web crawler (crawler.archive.org).
8  *
9  * Heritrix is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU Lesser Public License as published by
11  * the Free Software Foundation; either version 2.1 of the License, or
12  * any later version.
13  *
14  * Heritrix is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17  * GNU Lesser Public License for more details.
18  *
19  * You should have received a copy of the GNU Lesser Public License
20  * along with Heritrix; if not, write to the Free Software
21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22  */
23 package org.archive.net.md5;
24
25 import java.io.IOException JavaDoc;
26 import java.io.InputStream JavaDoc;
27 import java.net.URL JavaDoc;
28 import java.net.URLConnection JavaDoc;
29 import java.net.URLStreamHandler JavaDoc;
30
31 /**
32  * A protocol handler for an 'md5' URI scheme.
33  * Md5 URLs look like this: <code>md5:deadbeefdeadbeefdeadbeefdeadbeef</code>
34  * When this handler is invoked against an md5 URL, it passes the raw md5 to
35  * the configured script as an argument. The configured script then does the
36  * work to bring the item pointed to by the md5 local so we can open a Stream
37  * on the local copy. Local file is deleted when we finish. Do
38  * {@link org.archive.net.DownloadURLConnection#getFile()} to get name of
39  * temporary file.
40  *
41  * <p>You need to define the system property
42  * <code>-Djava.protocol.handler.pkgs=org.archive.net</code> to add this handler
43  * to the java.net.URL set. Also define system properties
44  * <code>-Dorg.archive.net.md5.Md5URLConnection.path=PATH_TO_SCRIPT</code> to
45  * pass path of script to run as well as
46  * <code>-Dorg.archive.net.md5.Md5URLConnection.options=OPTIONS</code> for
47  * any options you'd like to include. The pointed-to PATH_TO_SCRIPT
48  * will be invoked as follows: <code>PATH_TO_SCRIPT OPTIONS MD5
49  * LOCAL_TMP_FILE</code>. The LOCAL_TMP_FILE file is made in
50  * <code>java.io.tmpdir</code> using java tmp name code.
51  * @author stack
52  */
53 public class Handler extends URLStreamHandler JavaDoc {
54     protected URLConnection JavaDoc openConnection(URL JavaDoc u) {
55         return new Md5URLConnection(u);
56     }
57
58     /**
59      * Main dumps rsync file to STDOUT.
60      * @param args
61      * @throws IOException
62      */
63     public static void main(String JavaDoc[] args)
64     throws IOException JavaDoc {
65         if (args.length != 1) {
66             System.out.println("Usage: java java " +
67                 "-Djava.protocol.handler.pkgs=org.archive.net " +
68                 "org.archive.net.md5.Handler " +
69                 "md5:deadbeefdeadbeefdeadbeefdeadbeef");
70             System.exit(1);
71         }
72         System.setProperty("org.archive.net.md5.Md5URLConnection.path",
73             "/tmp/manifest");
74         System.setProperty("java.protocol.handler.pkgs", "org.archive.net");
75         URL JavaDoc u = new URL JavaDoc(args[0]);
76         URLConnection JavaDoc connect = u.openConnection();
77         // Write download to stdout.
78 final int bufferlength = 4096;
79         byte [] buffer = new byte [bufferlength];
80         InputStream JavaDoc is = connect.getInputStream();
81         try {
82             for (int count = is.read(buffer, 0, bufferlength);
83                     (count = is.read(buffer, 0, bufferlength)) != -1;) {
84                 System.out.write(buffer, 0, count);
85             }
86             System.out.flush();
87         } finally {
88             is.close();
89         }
90     }
91 }
92
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