public class MainActivity extends AppCompatActivity implements View.OnClickListener, Mvp.fff {

  private EditText mUsername;
  private EditText mPassword;
  private Button login;
  private ProgressDialog mProgressDialog;
  private Mvp mMvp;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    initView();

     mMvp = new Mvp(this);

  }
  private void initView() {
    mUsername = (EditText) findViewById(R.id.username);
    mPassword = (EditText) findViewById(R.id.password);
    login = (Button) findViewById(R.id.login);

    login.setOnClickListener(this);

    //動態的創建一個進度條
    mProgressDialog = new ProgressDialog(this);
  }

  @Override
  public void onClick(View view) {

    switch (view.getId()){
      case R.id.login:
        String user = mUsername.getText().toString();
        String pass = mPassword.getText().toString();
        final User users = new User();
        users.username=user;
        users.password=pass;


        Boolean empty = mMvp.isEmpty(users);
        if (empty){

          mProgressDialog.show();
          mMvp.isLogin(users);
        }else {

          Toast.makeText(MainActivity.this, "輸入不能為空", Toast.LENGTH_SHORT).show();
          return;
        }

        break;
    }

  }

  @Override
  public void success() {

    runOnUiThread(new Runnable() {
      @Override
      public void run() {
        mProgressDialog.dismiss();
        Toast.makeText(MainActivity.this, "歡迎回來,思密達", Toast.LENGTH_SHORT).show();
      }
    });
  }

  @Override
  public void doil() {

    runOnUiThread(new Runnable() {
      @Override
      public void run() {
        mProgressDialog.dismiss();
        Toast.makeText(MainActivity.this, "登錄失敗,賬號密碼有問題", Toast.LENGTH_SHORT).show();
      }
    });
  }

  @Override
  protected void onDestroy() {
    super.onDestroy();
    mMvp=null;
  }
}

public class UserLogin {  //MVC Controller層

  public boolean login(User users){
    SystemClock.sleep(1000);


    if ("frq".equals(users.username)&&"frq".equals(users.password)){
      return true;
    }else {
      return false;
    }

  }
}

public class Mvp {  //MVP Precenter層

  public Mvp(fff fff) {
    mFff = fff;
  }

  public Boolean isEmpty(User users){
    if (TextUtils.isEmpty(users.username) || TextUtils.isEmpty(users.password)){

      return false;
    }else {
      return true;
    }
  }

  public void isLogin(final User users){
    new Thread(){
      @Override
      public void run() {
        UserLogin login = new UserLogin();
        boolean b = login.login(users);


        if (b){
          mFff.success();
        }else {
          mFff.doil();
        }

      }
    }.start();
  }

  public interface fff{
    void success();
    void doil();
  }

  private fff mFff;

}
===========================================
public class Precenter {
  public Precenter(fff fff) {
    mFff = fff;
  }

  public void As(String urlString){
    new AsyncTask<String, Void, ArrayList<FirstBean.ResultBean>>() {
      @Override
      protected ArrayList<FirstBean.ResultBean> doInBackground(String... strings) {

        String s = new HttpUrl().toString(strings[0]); //調用外部類

        FirstBean firstBean = new Gson().fromJson(s, FirstBean.class); //gson解析
        if (firstBean!=null){
          return (ArrayList<FirstBean.ResultBean>) firstBean.getResult();
        }
        return null;

      }

      @Override
      protected void onPostExecute(ArrayList<FirstBean.ResultBean> resultBeans) {
        super.onPostExecute(resultBeans);
        if (resultBeans!=null){
          mFff.success(resultBeans);
        }else {
          mFff.bai();
        }

      }
    }.execute(urlString);
  }

  public interface fff{

    void success(ArrayList<FirstBean.ResultBean> resultBeans);
    void bai();
  };
  private fff mFff;
}