Download

public class DownloadFile extends AsyncTask<String, Void, String> {


    @Override
    protected String doInBackground(String... params) {
        try {

            String html = null;

                html = sendRequest(params[0]);
                Log.d(this.getClass().getName(), html);
            return html;
        } catch (Exception e) {
            Log.e(this.getClass().getName(), "Fehler in der SST", e);
        }
        return null;

    }

    public String sendRequest(String urlStr) throws Exception {
        // Standardvalidierung
        if (urlStr == null || urlStr.isEmpty()) {
            throw new InvalidParameterException("Der Parameter urlStr ist null oder leer!");
        }

        // Verbindung erstellen
        HttpURLConnection connection = null;

        // hier kann eine Exception fliegen, wenn es keine URL ist
        URL url = new URL(urlStr);
        connection = (HttpURLConnection) url.openConnection();
        connection.setDoInput(true);
        connection.setRequestMethod("GET");
        connection.setUseCaches(false);

        // Antwort erstellen
        StringBuilder str = new StringBuilder();
        BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream()));
        String line = "\n";
        while ((line = br.readLine()) != null) {
            str.append(line + System.getProperty("line.separator"));
        }

        // Antwort wieder geben
        return str.toString();
    }

}