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1 package org.objectweb.celtix.tools.utils;
2
3 import java.net.MalformedURLException  ;
4 import java.net.URL ;
5 import java.net.URLStreamHandler ;
6 import java.util.StringTokenizer ;
7
8 public final class URLFactory {
9 public static final String PROTOCOL_HANDLER_PKGS = "java.protocol.handler.pkgs";
10 public static final String UNKNOWN_PROPTOCL_EX_MSG = "unknown protocol: ";
11
12 private URLFactory() {
13
14 }
15
16 public static URL createURL(String spec) throws MalformedURLException {
17 return createURL(null, spec);
18 }
19
20 public static URL createURL(URL context, String spec) throws MalformedURLException {
21 URL url = null;
22 try {
23 url = new URL (context, spec);
24 } catch (MalformedURLException mue) {
25
26 String msg = mue.getMessage();
27 if (msg.indexOf(UNKNOWN_PROPTOCL_EX_MSG) != -1) {
28 URLStreamHandler handler = findHandler(msg.substring(UNKNOWN_PROPTOCL_EX_MSG.length()));
29 if (handler != null) {
30 url = new URL (context, spec, handler);
31 }
32 }
33 if (url == null) {
34 throw mue;
35 }
36 }
37 return url;
38 }
39
40 public static URLStreamHandler findHandler(String protocol) {
41
42 URLStreamHandler handler = null;
43 String packagePrefixList = System.getProperty(PROTOCOL_HANDLER_PKGS, "");
44 StringTokenizer packagePrefixIter = new StringTokenizer (packagePrefixList, "|");
45 while (handler == null && packagePrefixIter.hasMoreTokens()) {
46 String packagePrefix = packagePrefixIter.nextToken().trim();
47 try {
48 String clsName = packagePrefix + "." + protocol + ".Handler";
49 Class cls = null;
50 try {
51 cls = Class.forName(clsName);
52 } catch (ClassNotFoundException e) {
53 ClassLoader cl = Thread.currentThread().getContextClassLoader();
54 if (cl != null) {
55 cls = cl.loadClass(clsName);
56 }
57 }
58 if (cls != null) {
59 handler = (URLStreamHandler )cls.newInstance();
60 }
61 } catch (Exception ignored) {
62 ignored.getMessage();
63 }
64 }
65 return handler;
66 }
67 }
68 |
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