如何让app等待服务连接和身份验证

Question

我需要我的应用程序在加载屏幕上等待，以便可以建立与服务器的连接，然后使用SaveSharedPreference自动输入用户保存的凭据，然后转到MainActivity中的下一页。

通过onCreate块中的调用服务进行连接：

startService(new Intent(LoggingIn.this, MessagingService.class));

并且用户凭据来自SaveSharedPreference并在try / catch块中发送到服务器：

                result = imService.authenticateUser(
                        SaveSharedPreference
                                .getUserName(getApplicationContext()),
                        SaveSharedPreference
                                .getPassword(getApplicationContext()));

目前，应用程序只是启动然后崩溃。我尝试使用Thread.sleep（500），但只是关闭应用程序，并发布此错误：

1. 如何在发送authenticateUser

之前获取上述功能并让我的应用等待与服务器的连接

2. 在我的应用尝试启动authenticateUser之前，等待使用MainActivity成功登录？

       setContentView(R.layout.loading_splash_page);
   
       // If already logged in, pull the information and send to server
       // to
       // auto log in
   
       Thread loginThread = new Thread() {
           private Handler handler = new Handler();
   
           @Override
           public void run() {
               // String result = null;
   
               try {
   
                   result = imService.authenticateUser(
                           SaveSharedPreference
                                   .getUserName(getApplicationContext()),
                           SaveSharedPreference
                                   .getPassword(getApplicationContext()));
   
               } catch (UnsupportedEncodingException e) {
   
                   e.printStackTrace();
               }
   
               if (result == null || result.equals(AUTHENTICATION_FAILED)) {
                   /*
                    * Authenticatin failed, inform the user
                    */
                   handler.post(new Runnable() {
                       public void run() {
                           Toast.makeText(
                                   getApplicationContext(),
                                   R.string.make_sure_username_and_password_correct,
                                   Toast.LENGTH_LONG).show();
   
                           // showDialog(MAKE_SURE_USERNAME_AND_PASSWORD_CORRECT);
                       }
                   });
   
               } else {
   
                   /*
                    * if result not equal to authentication failed, result
                    * is equal to friend and group list of the user 0: is
                    * for friends, 1: is for groups
                    */
                   handler.post(new Runnable() {
                       public void run() {
                           Intent i = new Intent(LoggingIn.this,
                                   MainActivity.class);
                           startActivity(i);
                           LoggingIn.this.finish();
   
                       }
                   });
   
               }
   
           }
       };
       loginThread.start();
   

ADDITION imService的服务方式：

private ServiceConnection mConnection = new ServiceConnection() {
        public void onServiceConnected(ComponentName className, IBinder service) {
            // This is called when the connection with the service has been
            // established, giving us the service object we can use to
            // interact with the service. Because we have bound to a explicit
            // service that we know is running in our own process, we can
            // cast its IBinder to a concrete class and directly access it.
            imService = ((MessagingService.IMBinder) service).getService();

            if (imService.isUserAuthenticated() == true) {
                // Intent i = new Intent(LoggingIn.this, ListOfFriends.class);
                Intent i = new Intent(LoggingIn.this, MainActivity.class);
                startActivity(i);
                LoggingIn.this.finish();
            }
        }

        public void onServiceDisconnected(ComponentName className) {
            // This is called when the connection with the service has been
            // unexpectedly disconnected -- that is, its process crashed.
            // Because it is running in our same process, we should never
            // see this happen.
            imService = null;
            Toast.makeText(LoggingIn.this, R.string.local_service_stopped,
                    Toast.LENGTH_SHORT).show();
        }
    };