[Answered ]-Http connection between java applet and django server for post request

My original question asked for suggestions to get more information from the django server. I guess the answer I needed was found at java.io.IOException: Server returned HTTP response code: 500.

Java’s getInputStream method of a URLConnection object throws an exception when the server returns an error code (such as 500). The solution was to use getErrorStream instead. This allowed me to access the html error information produced by django’s server.

The final working code for the logging method of my applet is –

public boolean log(String logURL) {

    String charset = "UTF-8";
    String logData = logBuffer.toString();
    OutputStream output = null;
    HttpURLConnection conn = null;
    BufferedReader reader = null;
    InputStream in = null;

    try {
        String query = String.format("log=%s", URLEncoder.encode(logData, charset));
        conn = (HttpURLConnection) new URL(logURL).openConnection();
        conn.setDoOutput(true);
        conn.setRequestProperty("Accept-Charset", charset);
        conn.setRequestProperty("Content-Type","application/x-www-form-urlencoded;charset=" + charset);
        output = conn.getOutputStream();
        output.write(query.getBytes(charset));

    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
        return false;
    } catch (MalformedURLException e) {
        e.printStackTrace();
        return false;
    } catch (IOException e) {
        e.printStackTrace();
        return false;
    } finally {
         if (output != null) try { output.close(); } catch (IOException e) {e.printStackTrace();}
    }

    // Handle the response
    try {
        int responseCode = conn.getResponseCode();
        if (responseCode == 200) {
            in = conn.getInputStream();
        } else {
            in = conn.getErrorStream();
        }
        reader = new BufferedReader(new InputStreamReader(in));
        String line;
        logNote("reading response");
        while ((line = reader.readLine()) != null) {
            System.out.println(line);
        }
        reader.close();         
        if (responseCode == 200) {
            return true;
            }
        else {
            return false;
        }

    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
        return false;
    } catch (IOException e) {
        e.printStackTrace();
        return false;
    } finally {
        if (reader != null) try { reader.close(); } catch (IOException e) {e.printStackTrace();}
    }   
}

Using java.net.URLConnection to fire and handle HTTP requests was very informative.

Hope this is helpful for someone else.