10 OkHttp Best Practices

OkHttp is an open-source library that helps developers send and receive HTTP requests. It is a popular choice for Android developers because it is lightweight and efficient.

However, there are certain best practices that developers should follow when using OkHttp. This article will discuss 10 OkHttp best practices that developers should keep in mind when building their applications. Following these best practices will help ensure that your application is secure and efficient.

1. Use OkHttpClient to make your requests

OkHttpClient is an HTTP client that allows you to make requests and receive responses from a server. It provides features such as connection pooling, transparent compression, response caching, and more. By using OkHttpClient, you can ensure that your requests are sent efficiently and securely.

Using OkHttpClient also makes it easier to customize the request parameters for each request. You can set headers, timeouts, authentication credentials, and other options on the client before making the request. This helps reduce the amount of code needed to make a request and ensures that all requests have the same settings.

Additionally, OkHttpClient supports asynchronous requests, which means that multiple requests can be made at once without blocking the main thread. This improves performance by allowing multiple requests to be processed in parallel. Asynchronous requests also help prevent network errors from affecting the user experience.

2. Configure the client with a connection pool and thread pool

Configuring the client with a connection pool and thread pool is beneficial because it allows for reuse of existing connections, which reduces latency and improves performance. This is especially important when making multiple requests to the same server or domain. The connection pool stores idle connections that can be reused for subsequent requests, while the thread pool manages the threads used to execute requests.

To configure the client with a connection pool and thread pool, you need to create an OkHttpClient instance using the newBuilder() method. Then, set the connection pool size and thread pool size by calling the connectionPool() and dispatcher() methods respectively. Finally, build the client using the build() method.

3. Leverage HTTP/2 features like multiplexing, header compression, and server push

Multiplexing allows multiple requests to be sent over a single TCP connection, which reduces the number of round trips needed for each request and response. This can significantly reduce latency and improve performance.

Header compression reduces the size of HTTP headers by compressing them before they are sent over the network. This helps reduce bandwidth usage and speeds up page loading times.

Server push is a feature that allows the server to send additional resources to the client without waiting for the client to request them. This can help reduce latency and improve performance as well.

OkHttp supports all these features out-of-the-box, so it’s easy to take advantage of them. All you need to do is enable HTTP/2 in your OkHttp client and then use the appropriate methods to make use of the features. For example, if you want to use header compression, you can call the setCompression() method on the Request object. Similarly, if you want to use server push, you can call the enqueue() method on the PushPromise object.

4. Utilize response caching for faster network round trips

Response caching allows OkHttp to avoid the network completely for repeat requests. When a request is made, OkHttp will first check its cache and if it finds a valid cached response, it will return that instead of executing the network call. This can significantly reduce latency as well as save battery life by avoiding unnecessary network calls.

To enable response caching in OkHttp, you need to create an instance of Cache with a directory and size limit. Then, you need to pass this Cache instance into the OkHttpClient builder when creating your client. Finally, you must also set the appropriate headers on the server side so that responses are properly cached. The most important header is “Cache-Control” which specifies how long the response should be cached.

5. Take advantage of request batching

Request batching is a technique that allows multiple requests to be sent in one single request. This reduces the number of round trips between the client and server, which can significantly improve performance. It also reduces the amount of data transferred over the network, as only one request needs to be sent instead of multiple individual ones. To take advantage of this feature, OkHttp provides an API for creating batches of requests. The API allows developers to add multiple requests to a batch, set parameters such as timeouts, and then send them all at once. By using this API, developers can easily reduce the number of requests their application makes and improve its overall performance.

6. Enable automatic retries on failed requests

When a request fails, it can be due to many reasons such as network issues or server errors. By enabling automatic retries on failed requests, OkHttp will automatically attempt to re-send the request if it fails. This helps reduce the number of failed requests and increases the chances of successful responses.

To enable automatic retries with OkHttp, you need to create an instance of the RetryInterceptor class and add it to your OkHttp client. The RetryInterceptor takes two parameters: maxRetries and backoffMultiplier. MaxRetries is the maximum number of times that the request should be retried before giving up, while backoffMultiplier is used to increase the delay between each retry. Once configured, the RetryInterceptor will handle all the retries for you.

7. Use Okio for efficient I/O operations

Okio is a library that provides efficient I/O operations for Java and Android applications. It was designed to be used with OkHttp, an HTTP client library for Java and Android. By using Okio, developers can reduce the amount of time spent on I/O operations by taking advantage of features such as buffering, segmented reads and writes, and asynchronous I/O.

Using Okio also helps improve performance when dealing with large files or streams of data. The library allows developers to read and write data in chunks, which reduces memory usage and improves overall throughput. Additionally, Okio supports backpressure, meaning it will pause reading from a source if the consumer cannot keep up with the rate at which data is being produced. This prevents the system from becoming overloaded and ensures that resources are not wasted.

8. Implement an interceptor chain for customizing request behavior

An interceptor chain is a series of interceptors that are called sequentially when making a request. Each interceptor can modify the request before it’s sent, or modify the response after it’s received. This allows for customizing requests and responses in a variety of ways, such as adding headers, logging requests/responses, caching responses, etc.

To implement an interceptor chain with OkHttp, you need to create your own Interceptor class which implements the Interceptor interface. In this class, you will define what actions should be taken on each request and response. Then, you add the interceptor to the OkHttp client using the .addInterceptor() method. Finally, you call the enqueue() method on the Request object to execute the request. The interceptor chain will then be executed automatically.

Using an interceptor chain provides many benefits, including improved performance, better control over requests and responses, and easier debugging. It also makes it easy to customize requests and responses without having to manually edit them every time.

9. Consider using WebSockets for bidirectional communication

WebSockets are a great way to enable real-time communication between the client and server. They provide an efficient, low latency connection that can be used for both sending and receiving data. This is especially useful when dealing with large amounts of data or frequent updates from the server. With WebSockets, the client only needs to establish one connection and then it can send and receive messages without having to reestablish the connection each time. This reduces overhead and makes communication more efficient. Additionally, WebSockets allow for asynchronous communication, meaning that the client does not have to wait for a response before sending another request. This allows for faster responses and better user experience. To use WebSockets with OkHttp, you need to create a WebSocketListener object and pass it into the newWebSocket() method on the OkHttpClient instance. The listener will handle all incoming messages and events related to the WebSocket connection.

10. Monitor performance metrics to ensure optimal usage

Monitoring performance metrics helps to identify any issues that may be causing slowdowns or other problems. This can help you quickly diagnose and fix the issue, as well as prevent similar issues from occurring in the future. Additionally, monitoring performance metrics allows you to track usage trends over time, so you can better understand how your application is performing and make adjustments accordingly.

To monitor performance metrics with OkHttp, you can use a library such as OkLog, which provides an easy-to-use API for logging requests and responses. You can also use third-party tools like New Relic or AppDynamics to collect and analyze data about your application’s performance. Finally, you can use the built-in metrics provided by OkHttp itself, such as request/response times, connection pool size, and more.