URL ref = file.toURL();
URL ref; if (file.isAbsolute()) ref = file.toURL(); else { URL installURL = LocationManager.getInstallLocation().getURL();  File installPath = new File(installURL.getPath()); file = makeAbsolute(installPath, file); ref = file.toURL(); }
	public synchronized void connect() throws IOException {		if (!connected) {			// TODO assumes that reference URLs are always based on file: URLs.			// There are not solid usecases to the contrary. Yet.			// Construct the ref URL carefully so as to preserve UNC paths etc.			File file = new File(url.getPath().substring(5));			URL ref = file.toURL();			if (!file.exists())				throw new FileNotFoundException();			reference = ref;		}	}