How to specify a default user agent for okhttp 2.x requests

Question

I am using okhttp 2.0 in my Android app and didn't find a way to set some common User Agent for all outgoing requests.

I thought I could do something like

OkHttpClient client = new OkHttpClient();
client.setDefaultUserAgent(...)

...but there's no such method or similar. Of course I could provide some extension utility method which would wrap a RequestBuilder to attach .header("UserAgent") and then I would use it for building all my requests, but I thought maybe I missed some existing and simpler way?

Answer 1

You can use an interceptor to add the User-Agent header to all your requests.

For more information about okHttp interceptors see http://square.github.io/okhttp/interceptors/

Example implementation of this interceptor:

/* This interceptor adds a custom User-Agent. */
public class UserAgentInterceptor implements Interceptor {

    private final String userAgent;

    public UserAgentInterceptor(String userAgent) {
        this.userAgent = userAgent;
    }

    @Override
    public Response intercept(Chain chain) throws IOException {
        Request originalRequest = chain.request();
        Request requestWithUserAgent = originalRequest.newBuilder()
            .header("User-Agent", userAgent)
            .build();
        return chain.proceed(requestWithUserAgent);
    }
}

Test for the UserAgentInterceptor:

public void testUserAgentIsSetInRequestHeader() throws Exception {

    MockWebServer server = new MockWebServer();
    server.enqueue(new MockResponse().setBody("OK"));
    server.play();
    String url = server.getUrl("/").toString();

    OkHttpClient client = new OkHttpClient();
    client.networkInterceptors().add(new UserAgentInterceptor("foo/bar"));
    Request testRequest = new Request.Builder().url(url).build()
    String result = client.newCall(testRequest).execute().body().string();
    assertEquals("OK", result);

    RecordedRequest request = server.takeRequest();
    assertEquals("foo/bar", request.getHeader("User-Agent"));
}