getting java exception: java.net.MalformedURLException: no protocol

public static void main(String[] args) {
	try {
		java.net.URL connection_url = new java.net.URL("http://:/path");
		System.out.println("Instantiated new URL: " + connection_url);
	}
	catch (MalformedURLException e) {
		e.printStackTrace();
	}
}