URLEncoder ile türkçe karakter sorunu

URLEncoder kullanarak türkçe karakter sorununu aşmaya çalışıyorum fakat başarılı olamadım.

Java Kodlaması;

URL url = new URL(register_url);
                HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();
                httpURLConnection.setRequestMethod("POST");
                httpURLConnection.setDoOutput(true);
                httpURLConnection.setDoInput(true);
                OutputStream outputStream = httpURLConnection.getOutputStream();
                BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream, "UTF-8"));
                String post_data = URLEncoder.encode("user_name", "UTF-8")+"="+URLEncoder.encode(user_name, "UTF-8")+"&"+URLEncoder.encode("password", "UTF-8")+"="+URLEncoder.encode(password, "UTF-8");
                //String post_data = "user_name="+user_name+"&password="+password;
                Log.d("Kayıt Ol Argümanları", post_data);
                bufferedWriter.write(post_data);
                bufferedWriter.flush();
                bufferedWriter.close();
                outputStream.close();
                InputStream inputStream = httpURLConnection.getInputStream();
                BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream, "ISO-8859-1"));

Android Girdisi;

üğşçöı

Android Log Çıktısı;

user_name=%C3%BC%C4%9F%C5%9F%C3%A7%C3%B6%C4%B1

MySQL Çıktısı (latin5_turkish_ci ve utf8_general_ci);

üğşçöı