Auslesen einer Webseite beschleunigen

    /**
     * Liefert die angegebene Webseite als String zurück.
     *
     * @return HTML der Webseite.
     */
    private String getSourceCode() {
        URL url = null;
        try {
            url = new URL(wantedURL);
        } catch (MalformedURLException e) {
            writeErrorLogOnSD(e);
            e.printStackTrace();
        }
        URLConnection conn = null;
        try {
            conn = url.openConnection();
        } catch (IOException e) {
            writeErrorLogOnSD(e);
            e.printStackTrace();
        } catch (NullPointerException e) {
            writeErrorLogOnSD(e);
            e.printStackTrace();
        }
        // editText.getText().toString()
        BufferedReader rd = null;
        try {
            rd = new BufferedReader(
                    new InputStreamReader(conn.getInputStream()));
        } catch (IOException e) {
            writeErrorLogOnSD(e);
            e.printStackTrace();
        } catch (NullPointerException e) {
            writeErrorLogOnSD(e);
            e.printStackTrace();
        }

        String line = "";
        String oldLine = "";
        if (rd != null) {
            System.out.println("Got Line");
            try {
                while ((line = rd.readLine()) != null) {
                    oldLine = oldLine + line;
                }
            } catch (IOException e) {
                writeErrorLogOnSD(e);
                e.printStackTrace();
            }
            try {
                rd.close();
            } catch (IOException e) {
                writeErrorLogOnSD(e);
                e.printStackTrace();
            }
        } else {
            System.out.println("No Line");
            error = true;
        }

        return oldLine;
    }

                /*
                while ((line = rd.readLine()) != null) {
                    oldLine = oldLine + line;
                }
                */
                StringBuilder sb = new StringBuilder();
                while ((line = rd.readLine()) != null) {
                    //oldLine = oldLine + line;
                    sb.append(line);
                }
                oldLine =  sb.toString();