OkHttpClient

Factory for calls, which can be used to send HTTP requests and read their responses.

OkHttpClients Should Be Shared

OkHttp performs best when you create a single OkHttpClient instance and reuse it for all of your HTTP calls. This is because each client holds its own connection pool and thread pools. Reusing connections and threads reduces latency and saves memory. Conversely, creating a client for each request wastes resources on idle pools.

Use new OkHttpClient() to create a shared instance with the default settings:

// The singleton HTTP client.
public final OkHttpClient client = new OkHttpClient();

Or use new OkHttpClient.Builder() to create a shared instance with custom settings:

// The singleton HTTP client.
public final OkHttpClient client = new OkHttpClient.Builder()
    .addInterceptor(new HttpLoggingInterceptor())
    .cache(new Cache(cacheDir, cacheSize))
    .build();

Customize Your Client With newBuilder()

You can customize a shared OkHttpClient instance with newBuilder. This builds a client that shares the same connection pool, thread pools, and configuration. Use the builder methods to add configuration to the derived client for a specific purpose.

This example shows the single instance with default configurations.

public final OkHttpClient client = new OkHttpClient.Builder()
    .readTimeout(1000, TimeUnit.MILLISECONDS)
    .writeTimeout(1000, TimeUnit.MILLISECONDS)
    .build();

This example shows a call with a short 500 millisecond read timeout and a 1000 millisecond write timeout. Original configuration is kept, but can be overriden.

OkHttpClient eagerClient = client.newBuilder()
    .readTimeout(500, TimeUnit.MILLISECONDS)
    .build();
Response response = eagerClient.newCall(request).execute();

Shutdown Isn't Necessary

The threads and connections that are held will be released automatically if they remain idle. But if you are writing a application that needs to aggressively release unused resources you may do so.

Shutdown the dispatcher's executor service with ExecutorService.shutdown. This will also cause future calls to the client to be rejected.

client.dispatcher().executorService().shutdown();

Clear the connection pool with evictAll(). Note that the connection pool's daemon thread may not exit immediately.

client.connectionPool().evictAll();

If your client has a cache, call close(). Note that it is an error to create calls against a cache that is closed, and doing so will cause the call to crash.

client.cache().close();

OkHttp also uses daemon threads for HTTP/2 connections. These will exit automatically if they remain idle.