Preface

Recently, I have seen a lot of MVP frameworks in the new project, and then I built the MVP framework myself. So I summarize them here and hope you can learn from each other.

I. Basic Architecture

The structure of MVP is briefly introduced, full name: Model-View-Presenter; it is evolved from the classical model MVC, their basic ideas have something in common:
Controller/Presenter is responsible for processing logic
Model provides data
View is responsible for display

First, let's have a look at the catalogue. Have a basic understanding.

1. Base Series

The base series is designed to make it easy to write public code.
BasePresenter

public interface BasePresenter {
    void subscribe();

    void unSubscribe();
}

These two methods are defined to control the life cycle of objects in Presenter. This is also an optimization of the MVP framework.

BaseView

public interface BaseView<T> {

}

The other two are not shown. They are almost the same.

II. Construction of MainActivity

1,MainContart

interface MainContract {
    interface View extends BaseView<Presenter> {
        void onError(String s);

        void onSuccess(BookBean bookBean);
    }

    interface Presenter extends BasePresenter {
        void getData(String search);
    }
}

This class exists in order to unify the methods of managing View and Presenter. The new method should be written directly here and then go to the corresponding page alt+Enter.
Here the generic T of View is set to the Presenter interface below.

II. MainPresenter

And then get this Presenter

class MainPresenter implements MainContract.Presenter {
    private MainContract.View view;

    MainPresenter(MainContract.View view) {
        this.view = view;
    }

    @Override
    public void subscribe() {
    }

    @Override
    public void unSubscribe() {
    }

    @Override
    public void getData(String search) {
    }
}

This is where the View layer is bound in the constructor.

Then post a Presenter class with the content already written.

class MainPresenter implements MainContract.Presenter {
    private MainContract.View view;
    private CompositeDisposable compositeDisposable;

    MainPresenter(MainContract.View view) {
        this.view = view;
        compositeDisposable = new CompositeDisposable();
    }

    @Override
    public void subscribe() {
    }

    @Override
    public void unSubscribe() {
        compositeDisposable.clear();
    }

    @Override
    public void getData(String search) {
        RetrofitManager.getInstance().getServer().searchBook("Princeling")
                .subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(new Observer<BookBean>() {
                    @Override
                    public void onSubscribe(Disposable d) {
                        compositeDisposable.add(d);
                    }

                    @Override
                    public void onNext(BookBean value) {
                        view.onSuccess(value);
                    }

                    @Override
                    public void onError(Throwable e) {
                        view.onError(e.toString());
                    }

                    @Override
                    public void onComplete() {

                    }
                });
    }
}

III. MainActivity

Finally, inherit the View interface in the activity interface

public class MainActivity extends AppCompatActivity implements MainContract.View {
    @BindView(R.id.activity_text)
    TextView textView;

    private MainContract.Presenter presenter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ButterKnife.bind(this);
        presenter = new MainPresenter(this);
        presenter.getData("data");
    }

    @Override
    protected void onResume() {
        super.onResume();
        presenter.subscribe();
    }

    @Override
    protected void onPause() {
        super.onPause();
        presenter.unSubscribe();
    }

    @Override
    public void onError(String s) {
        Log.e("error", s);
    }

    @Override
    public void onSuccess(BookBean bookBean) {
        textView.setText(bookBean.toString());
    }
}

Initialize the MainPresenter class in onCreate.

Retrofit+Rxjava2

RetrofitManager Management Tool Class:

public class RetrofitManager {
    private Retrofit retrofit;

    private RetrofitManager() {
        init();
    }

    private void init() {
        OkHttpClient client = new OkHttpClient.Builder().addInterceptor(new Interceptor() {
            @Override
            public okhttp3.Response intercept(Chain chain) throws IOException {
                Request original = chain.request();
                Request.Builder requestBuilder = original.newBuilder();
                //Request Body Customization: Unified Addition of token Parameters
                if (original.body() instanceof FormBody) {
                    FormBody.Builder newFormBody = new FormBody.Builder();
                    requestBuilder.method(original.method(), newFormBody.build());
                }
                Request request = requestBuilder.build();
                return chain.proceed(request);
            }
        }).build();

        retrofit = new Retrofit.Builder()
                .baseUrl(SERVER_HOST)
                .addConverterFactory(GsonConverterFactory.create())
                .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
                .callFactory(client)
                .build();

    }

    public ApiService getServer() {
        return retrofit.create(ApiService.class);
    }

    public static RetrofitManager getInstance() {
        return RetrofitManagerHolder.INSTANCE;
    }

    private static class RetrofitManagerHolder {
        private static final RetrofitManager INSTANCE = new RetrofitManager();
    }

}

ApiService interface class:

public interface ApiService {
    @GET("v2/book/search")
    Observable<BookBean> searchBook(@Query("tag") String tag);
}

The study of these two methods of use is to search for learning materials separately, which is still very rich.

summary

Here is the basic MVP framework I used in my project. It feels OK in practice. I haven't touched MVP with MVC before, but it's not difficult to really use MVP. As long as I take the first step, the rest are OK.
If you have any comments on my framework, you are welcome to point out in your comments. Thank you very much.