mvp契约类

public class MainActivity extends AppCompatActivity implements IContract.IView {

    private IContract.IPresenter presenter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        presenter = new PresenterImpl();
        presenter.attachView(this);
    }

    @Override
    public void requestDataPre(final String ss) {
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                Toast.makeText(MainActivity.this, ss, Toast.LENGTH_SHORT).show();
            }
        });
    }

    public void login(View view) {
        presenter.requestDataPre();
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        presenter.detachView(this);
    }
}

public interface IContract {
    interface IModel {

        interface ResponseStr{
            void sendMMsg(String ss);
        }

        void requestDataMod(ResponseStr responseStr);
    }

    interface IPresenter<IView> {

        void detachView(IView iView);

        void attachView(IView iView);

        void requestDataPre();
    }

    interface IView {
        void requestDataPre(String ss);
    }
}

public class ModelImpl implements IContract.IModel {

    @Override
    public void requestDataMod(final ResponseStr responseStr) {

        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    Thread.sleep(2000);
                    String ss="hahaha";
                    responseStr.sendMMsg(ss);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }).start();

    }
}

public class PresenterImpl implements IContract.IPresenter<IContract.IView> {

    IContract.IView iView;
    private IContract.IModel model;
    private WeakReference<IContract.IView> iViewWeakReference;
    private WeakReference<IContract.IModel> iModelWeakReference;

    @Override
    public void attachView(IContract.IView iView) {
        this.iView = iView;
        model = new ModelImpl();
        iViewWeakReference = new WeakReference<>(iView);
        iModelWeakReference = new WeakReference<>(model);
    }

    @Override
    public void detachView(IContract.IView iView) {
        iViewWeakReference.clear();
        iModelWeakReference.clear();
    }

    @Override
    public void requestDataPre() {
        model.requestDataMod(new IContract.IModel.ResponseStr() {
            @Override
            public void sendMMsg(String ss) {
                iView.requestDataPre(ss);

            }
        });
    }
}