You can use next code to retrieve list of files:

Code:
        try {
            URL url = new URL(YOUR_URL_HERE);
            InputStream inputStream = url.openStream();
            System.out.println("inputStream.available() = " + inputStream.available());

            BufferedReader br = new BufferedReader(new InputStreamReader(inputStream));

            String line = null;

            while ((line = br.readLine()) != null) {
                System.out.println("line = " + line);
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }