OData + RxJava + Retrofit 2 لتطبيق Android

Open Data Protocol (OData) — - . , HTTP-, XML JSON.

4.0, OData — , OASIS.

// Network
    implementation 'com.squareup.retrofit2:retrofit:2.7.1' //   Retrofit 2
    implementation 'com.squareup.retrofit2:converter-gson:2.7.1' //     JSON 
    implementation 'com.squareup.okhttp3:logging-interceptor:4.3.1' //  
    implementation 'com.squareup.retrofit2:adapter-rxjava2:2.7.1' //     RxJava
    implementation 'com.squareup.okhttp3:okhttp:4.3.1' // OkHttp -  HTTP-

public class NetworkService {

    private static final String TAG = "NetworkService";

    private static final NetworkService
            mInstance = new NetworkService();

    private String mToken;
    private Retrofit mRetrofit;

    public static NetworkService getInstance() {
        return mInstance;
    }

    private NetworkService() {

        RxJava2CallAdapterFactory rxAdapter =
                RxJava2CallAdapterFactory
                        .createWithScheduler(Schedulers.io());

        HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor();
        interceptor.setLevel(HttpLoggingInterceptor.Level.BODY); 

        OkHttpClient.Builder okHttpClient =
                new OkHttpClient.Builder()
                        .addInterceptor(interceptor)
                        .addInterceptor(chain -> {
                            Request newRequest =
                                    chain.request().newBuilder()
                                           .addHeader("Accept",
                                                     "application/json,text/plain,*/*")
                                           .addHeader("Content-Type",
                                                    "application/json;odata.metadata=minimal")
                                           .addHeader("Authorization", mToken)
                                    .build();

                            return chain.proceed(newRequest);
                        });

        Gson gson = new GsonBuilder()
                .setDateFormat("yyyy-MM-dd'T'HH:mm:ssZ")
                .create();

        mRetrofit = new Retrofit.Builder()
                .baseUrl(Const.BASE_URL)
                .addConverterFactory(GsonConverterFactory.create(gson))
                .addCallAdapterFactory(rxAdapter)
                .client(okHttpClient.build())
                .build();
    }
    public ApiService getNetworkClient(){
        return mRetrofit.create(ApiService.class);
    }
}

public interface ApiService {
//    
@GET("odata/product")
Observable<List<ProductsDto>> getProducts();
}

public class ProductsController {

    private ApiService mApiService;

    private List<ProductsDto> listProducts;
    private Gson gson;

    public ProductsController() {

        mApiService = App.getNetworkService().getNetworkClient();

        listProducts = new ArrayList<>();

        gson = new Gson();
    }

    public void productsBtnClick() {

        mApiService.getProducts()
                .subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(new DisposableObserver<List<ProductsDto>>() {
                    @Override
                    public void onNext(List<ProductsDto> products) {

                        listProducts.addAll(listProducts);
                    }

                    @Override
                    public void onError(Throwable e) {

                    }

                    @Override
                    public void onComplete() {
                    }
                });
    }

private void buttonGetProduct() {
//     
        String one = "odata/product?$filter=Id eq ";
        String id = "777";
        String tree = "&$expand=dateReading($orderby=Date desc)";
        String url = one + id + tree;

        mApiService.getProduct(url)
                .subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(new DisposableObserver<List<ProductDto>>() {
                    @Override
                    public void onNext(List<ProductDto> products) {

//       ,     JSON,
//         
                        mProductsDto.addAll(countersDtos);
                    }

                    @Override
                    public void onError(Throwable e) {
                    }

                    @Override
                    public void onComplete() {
                    }
                });
    }