求解和服务器通信问题

HttpURLConnection conn = null;
                    URL url = new URL("https://api.smratfarm.tk/client/login");
                    conn = (HttpURLConnection)url.openConnection();
                    conn.setRequestMethod("POST");
                    DataOutputStream out = new DataOutputStream(conn.getOutputStream());
                    out.writeBytes("username=debuger&password=debuger");
                    InputStream in = conn.getInputStream();
                    BufferedReader reader = new BufferedReader(new InputStreamReader(in));
                    StringBuilder response = new StringBuilder();
                    String line;
                    
                    while ((line = reader.readLine())!= null){
                        response.append(line);
                    }   
                    
                    Message message = new Message();
                    message.what = 0;
                    message.obj = response.toString();
                    handler.sendMessage(message);
                }catch(Exception e)
                {
                        
                        e.printStackTrace();
                }   
               
            }
        }).start();
    }