Android中的RxJava，Retrofit，MVP的使用

RxJava，Retrofit，MVP都是近几年讨论的比较热门的话题，我们也来凑个热闹！

本文不展开讨论，分别讨论的文章有很多，后续有时间给出RxJava，Retrofit的源码分析

先来说一下MVP（Model View Presenter）熟悉MVC结构的应该很容易理解MVP，这里先给出MVP的图解

MVP图解

• model具体业务逻辑处理的实现
• view负责显示数据、提供友好界面跟用户交互
• presenter负责完成View于Model间的交互

下面给出一个使用这三者的demo，由于使用Retrofit和RxJava，数据获取的过程变得很简洁，此demo没有按照严格的MVP结构，遵从了数据和view分开处理的原则，降低了代码的耦合度，少定义几个接口

View代码层

public class MainActivity extends AppCompatActivity implements LoadingBannerView{ 
    @Bind(R.id.show_banner_string) 
    TextView showBanner; 
    BannerPresenter presenter; 
    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState); 
        setContentView(R.layout.activity_main); 
        ButterKnife.bind(this); 
        presenter = new BannerPresenter(MainActivity.this);
        presenter.loadData(); 
    } 
     @Override 
    public void showData(List<BannerVO> bannerVOs) { 
            showBanner.setText(bannerVOs.get(i).getPicUrl()); 
    } 
    @Override 
    public void showNetworkErrorView() { } 
    @Override 
    public void hideNetworkErrorView() { } 
    @Override 
    public void showLoading() { } 
    @Override 
    public void hideLoading() { } 
    @Override 
    public void showEmptyView() { } 
    @Override 
    public void hideEmptyView() { } 
    @Override 
    public void showError(String message) { }
}

写的比较简单，根据需求私人私人定制

view层的接口

public interface LoadingBannerView extends LoadingDataView{
    void showData(List<BannerVO> bannerVOs);
}

public interface LoadingDataView { 
    void showNetworkErrorView(); 
    void hideNetworkErrorView(); 
    void showLoading(); 
    void hideLoading();
    void showEmptyView(); 
    void hideEmptyView(); 
    void showError(String message);
}

present层代码

public class BannerPresenter implements CommonPresenter { 
    LoadingBannerView view; 
    public BannerPresenter(LoadingBannerView view) { 
        this.view = view; 
    } 
    @Override 
    public void loadData() { 
        HttpService.getInstance().getCommonApi().getBannerList("", "", "", "") 
    .lift(new OperatorRequestMap<List<BannerVO>>())
    .subscribeOn(Schedulers.io())
    .observeOn(AndroidSchedulers.mainThread()) 
    .subscribe(new Action1<List<BannerVO>>() { 
        @Override 
        public void call(List<BannerVO> bannerVOs) { 
            if (bannerVOs != null && bannerVOs.size() > 0) { 
                view.showData(bannerVOs); 
            }else { 
                view.showEmptyView(); 
            } 
        } 
    }, new Action1<Throwable>() { 
        @Override 
        public void call(Throwable throwable) { 
            if (throwable instanceof NetworkConnectionException) {
                view.showNetworkErrorView(); 
              } 
          } 
    }); 
  }
 }

present层的接口

public interface CommonPresenter { void loadData();}

model层主要是实体，省略一百行代码...

RxJava使用

public class HttpService { 
     private CommonApi commonApi; 
     private HttpService() { 
        Retrofit.Builder builder = new Retrofit.Builder()
        .addCallAdapterFactory(RxJavaCallAdapterFactory.create())
        .addConverterFactory(GsonConverterFactory.create()) 
        .baseUrl(HttpContants.DEFAULT_HOST_URL); 
    OkHttpClient.Builder okHttpBuilder = new OkHttpClient.Builder()
    .addNetworkInterceptor(new Interceptor() { 
        @Override 
        public Response intercept(Chain chain) throws IOException { 
            Request request = chain.request(); 
            Request newReq = request.newBuilder() .build(); 
            return chain.proceed(newReq); 
        } 
    }); 
    if (BuildConfig.DEBUG){ 
        HttpLoggingInterceptor loggingInterceptor = new HttpLoggingInterceptor();
         loggingInterceptor.setLevel(HttpLoggingInterceptor.Level.BODY); 
        okHttpBuilder.addInterceptor(loggingInterceptor); 
      } 
    OkHttpClient client = okHttpBuilder.build();
    builder.client(client); 
    commonApi = builder.build().create(CommonApi.class); 
   } 
    private static class HttpServiceHandler{ 
        public static final HttpService INSTANCE = new HttpService();
    } 
    public static HttpService getInstance(){ 
        return HttpServiceHandler.INSTANCE; 
    } 
    public static CommonApi getCommonApi() { 
        return HttpService.getInstance().commonApi; 
    }
}

retrofit的使用

public interface CommonApi { 
    @FormUrlEncoded 
    @POST("") 
    Observable<BaseBean<List<BannerVO>>> getBannerList(@Field("") String method, @Field("") String bannerUpdateVer, @Field("") String sessionKey, @Field("") String bannerType);
}

欲知详情，请听下回解说

Demo地址：https://github.com/zimoguo/MVPDemo