CacheUtil.urlToPath method reads:
public static File urlToPath(URL location, String subdir) {
StringBuffer path = new StringBuffer();
if (subdir != null) {
path.append(subdir);
path.append(File.separatorChar);
}
path.append(location.getProtocol());
path.append(File.separatorChar);
path.append(location.getHost());
path.append(File.separatorChar);
path.append(location.getPath().replace('/', File.separatorChar));
return new File(JNLPRuntime.getBaseDir(), fixPath(path.toString()));
}
... which ignores the port number. So if I have multiple servers running on the same machine on a different port, netx will get confused about them.