public class UserModle{

   private String userName;
   private String passWord;

   public void setUserName(String userName) {
      // TODO Auto-generated method stub
      this.userName = userName;
   }

   public void setPassWord(String passWord) {
      // TODO Auto-generated method stub
      this.passWord = passWord;
   }

   public String getUserName() {
      // TODO Auto-generated method stub
      return userName;
   }

   public String getPassWord() {
      // TODO Auto-generated method stub
      return passWord;
   }

}

public interface IView {
}

public interface ILoginView extends IView {

    String getUserName();

    String getPassWord();

    void clearUserName();

    void clearPassword();

    void showLoading();

    void hideLoading();

    void isEmpty();

    void loginSuccess(UserModle userModle);

    void loginFail();

}

public interface IPresenter {

    public void clear();

    public boolean isEmpty();
}

public abstract class BasePresenter<T> implements IPresenter {

    public IView view;

    public BasePresenter(IView view) {
        this.view = view;
    }

    @Override
    public void clear() {
        // TODO Auto-generated method stub
        view = null;
    }

    public abstract T getView();

    public abstract void login();

    public abstract void clearInput();
}

public class LoginPresenter extends BasePresenter<ILoginView> {

    private ILoginNetWork loginNetWork;

    public LoginPresenter(ILoginView loginView) {
        super(loginView);
        // TODO Auto-generated constructor stub
        loginNetWork = new LoginNetWork();
    }

    @Override
    public boolean isEmpty() {
        ILoginView loginView = getView();
        if (loginView.getUserName().isEmpty() || loginView.getPassWord().isEmpty()) {
            return true;
        } else {
            return false;
        }
    }

    @Override
    public void login() {
        // TODO Auto-generated method stub
        final ILoginView loginView = getView();
        if (isEmpty()) {
            loginView.isEmpty();
            return;
        }
        loginView.showLoading();
        loginNetWork.login(loginView.getUserName(), loginView.getPassWord(), new ILoginListener() {

            @Override
            public void loginSuccess(final UserModle userModle) {
                // TODO Auto-generated method stub
                loginView.loginSuccess(userModle);
                loginView.hideLoading();
            }

            @Override
            public void loginFail() {
                // TODO Auto-generated method stub
                loginView.loginFail();
                loginView.hideLoading();
            }
        });
    }

    @Override
    public void clearInput() {
        // TODO Auto-generated method stub
        ILoginView loginView = getView();
        loginView.clearUserName();
        loginView.clearPassword();
    }

    @Override
    public void clear() {
        loginNetWork.removeRequest();
        loginNetWork = null;
        super.clear();
    }

    @Override
    public ILoginView getView() {
        return (ILoginView) view;
    }
}

public interface ILoginListener {

   void loginSuccess(UserModle userModle);

   void loginFail();

}

public interface ILoginNetWork {

   public void login(String userName, String passWord, ILoginListener loginListener);

   public void removeRequest();
}

public class LoginNetWork implements ILoginNetWork {

    private MyAsyncTask myAsyncTask;

    @Override
    public void login(String userName, String passWord, ILoginListener loginListener) {
        // TODO Auto-generated method stub
        myAsyncTask = new MyAsyncTask(userName, passWord, loginListener);
        myAsyncTask.execute();
    }

    @Override
    public void removeRequest() {
        myAsyncTask.cancel(true);
　　　　 myAsyncTask = null;
    }

    private static class MyAsyncTask extends AsyncTask {
        String userName;
        String passWord;
        ILoginListener loginListener;

        public MyAsyncTask(String userName, String passWord, ILoginListener loginListener) {
            this.userName = userName;
            this.passWord = passWord;
            this.loginListener = loginListener;
        }

        @Override
        protected Object doInBackground(Object[] params) {
            try {
                //模拟耗时操作
                Thread.sleep(2000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            return null;
        }

        @Override
        protected void onPostExecute(Object o) {
            super.onPostExecute(o);
            if ("name".equals(userName) && "123".equals(passWord)) {
                UserModle userModle = new UserModle();
                userModle.setUserName(userName);
                userModle.setPassWord(passWord);
                loginListener.loginSuccess(userModle);
            } else {
                loginListener.loginFail();
            }
        }
    }
}

public class MainActivity extends AppCompatActivity implements ILoginView {

    private LoginPresenter loginPresenter;
    private ProgressDialog dialog;
    private EditText view_username;
    private EditText view_password;
    private Button view_login;
    private Button view_clear;

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

        dialog = new ProgressDialog(this);
        loginPresenter = new LoginPresenter(this);

        view_username = (EditText) findViewById(R.id.view_username);
        view_password = (EditText) findViewById(R.id.view_password);
        view_login = (Button) findViewById(R.id.view_login);
        view_clear = (Button) findViewById(R.id.view_clear);

        view_login.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View arg0) {
                // TODO Auto-generated method stub
                if (loginPresenter != null) {
                    loginPresenter.login();
                }
            }
        });

        view_clear.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View arg0) {
                // TODO Auto-generated method stub
                if (loginPresenter != null) {
                    loginPresenter.clearInput();
                }
            }
        });

    }

    @Override
    public String getUserName() {
        // TODO Auto-generated method stub
        return view_username.getText().toString();
    }

    @Override
    public String getPassWord() {
        // TODO Auto-generated method stub
        return view_password.getText().toString();
    }

    @Override
    public void clearUserName() {
        // TODO Auto-generated method stub
        view_username.setText("");
    }

    @Override
    public void clearPassword() {
        // TODO Auto-generated method stub
        view_password.setText("");
    }

    @Override
    public void showLoading() {
        // TODO Auto-generated method stub
        dialog.show();
    }

    @Override
    public void hideLoading() {
        // TODO Auto-generated method stub
        dialog.dismiss();
    }

    @Override
    public void isEmpty() {
        // TODO Auto-generated method stub
        show("请输入用户名和密码！");
    }

    @Override
    public void loginSuccess(UserModle userBean) {
        // TODO Auto-generated method stub
        show("登陆成功！");
    }

    @Override
    public void loginFail() {
        // TODO Auto-generated method stub
        show("登陆失败！");
    }

    private void show(String str) {
        Log.d("CESHI", str);
        Toast.makeText(this, str, Toast.LENGTH_SHORT).show();
    }

    @Override
    protected void onDestroy() {
        // TODO Auto-generated method stub
        super.onDestroy();

        loginPresenter.clear();
        loginPresenter = null;
    }

}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <EditText
        android:id="@+id/view_username"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:inputType="text" />

    <EditText
        android:id="@+id/view_password"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:inputType="textPassword" />
    
    <Button 
        android:id="@+id/view_login"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:text="登陆"
        />
    
    <Button 
        android:id="@+id/view_clear"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:text="清除"
        />

</LinearLayout>

android MVP例子