int index = file.indexOf('/',1);
int index = file.indexOf('!',0);
	public PluginResURLConnection(URL url)		throws IOException	{		super(url);		String file = url.getFile();		int index = file.indexOf('/',1);		if(index == -1)			throw new IOException("Invalid plugin resource URL");		int start;		if(file.charAt(0) == '/')			start = 1;		else			start = 0;		pluginIndex = Integer.parseInt(file.substring(start,index));		resource = file.substring(index + 1);	}