Maximize Network Performance in Android with Retrofit and RxJava

Explore the powerful combination of Retrofit and RxJava for efficient network requests in Android apps in our blog post. Learn how to utilize reactive programming to elegantly handle asynchronous requests and provide an outstanding user experience.

What to Expect in This Post?

• Creating Retrofit Requests with RxJava: We’ll learn how to implement Retrofit requests in Android apps using RxJava.
• Performing Multiple Retrofit Requests with RxJava: We’ll see how to execute multiple requests sequentially and combine the results.
• Transforming Retrofit POJO Return Values: We’ll learn how to transform the return values of POJO classes to tailor them to our needs.

Fundamentals and Preparation

Before we begin, it’s important to understand that Retrofit is a REST client that uses OkHttp as an HttpClient and JSON parser for response parsing. We’ll be using Gson as the JSON parser. Integrating Retrofit into a project involves several steps, as shown below:

// Example of creating a Retrofit instance
HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor();
interceptor.setLevel(HttpLoggingInterceptor.Level.BODY);
OkHttpClient client = new OkHttpClient.Builder().addInterceptor(interceptor).build();

Gson gson = new GsonBuilder()
        .setLenient()
        .create();

Retrofit retrofit = new Retrofit.Builder()
        .baseUrl(BASE_URL)
        .client(client)
        .addConverterFactory(GsonConverterFactory.create(gson))
        .build();

Now that we’ve covered the basics, let’s walk through the integration of Retrofit and RxJava in a practical application.

Implementing Retrofit Requests with RxJava

To implement Retrofit requests with RxJava in an Android app, we need to follow a few steps:

1. Add Dependencies

First, we need to add the required dependencies in our build.gradle file.

implementation 'com.android.support:cardview-v7:27.1.0'
implementation 'com.android.support:design:27.1.0'
implementation('com.squareup.retrofit2:retrofit:2.3.0') {
    exclude module: 'okhttp'
}
// Add other dependencies here...

2. Define Interface

Define an interface specifying the API endpoints.

public interface CryptocurrencyService {
    @GET("{coin}-usd")
    Observable getCoinData(@Path("coin") String coin);
}

3. Perform Request

Execute the request and subscribe to the results.

CryptocurrencyService cryptocurrencyService = retrofit.create(CryptocurrencyService.class);
Observable cryptoObservable = cryptocurrencyService.getCoinData("btc");
cryptoObservable.subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .map(result -> result.ticker)
                .subscribe(this::handleResults, this::handleError);

Through these steps, we can implement Retrofit requests in our Android app and reactively respond to the results.

Conclusion

The combination of Retrofit and RxJava offers a powerful solution for managing network requests in Android apps. By leveraging RxJava, we can elegantly handle asynchronous requests and enable reactive programming. Integrating Retrofit requests with RxJava enables developers to build efficient and robust apps that provide an outstanding user experience.

We hope this post has provided you with insight into implementing Retrofit requests with RxJava in Android apps. Try it out in your next project and experience the benefits of reactive programming firsthand!