Canceled Message Submission Symbol

Avoiding the "ü" character in a string.

I have this symbol in my json data:

{"Name": "Hyüsin"}

when I do HttpPost in my android on a web server. it gives me a Bad Request error as an answer.

HttpPost Code:

    // uploads the data
public class UploadData extends AsyncTask<String, Integer, Boolean> {

        @Override
        protected Boolean doInBackground(String... url) {

            try {

                HttpPost request = new HttpPost(LogInActivity.SERVICE_URI + url[0]);

                request.setHeader("Content-type", "application/json; charset=utf-8");


                //THIS IS  {"Name": "Hyüsin"}               
                JSONObject jsonTaakkaart = taakkaart.serializeToObj();




                StringEntity entity = new StringEntity(jsonTaakkaart .toString());
                request.setEntity(entity);


                DefaultHttpClient httpClient = new DefaultHttpClient();
                HttpResponse response = httpClient.execute(request);


                return true;

            } catch (Exception e) {
                e.printStackTrace();
                return false;
            }

        }
    }