MockWebServer and Retrofit with Callback

Question

I would like to simulate network communication by MockWebServer. Unfortulatelly retrofit callbacks are never invoking. My code:

    MockWebServer server = new MockWebServer();
    server.enqueue(new MockResponse().setResponseCode(200).setBody("{}"));
    server.play();

    RestAdapter restAdapter = new RestAdapter.Builder().setConverter(new MyGsonConverter(new Gson()))
            .setEndpoint(server.getUrl("/").toString()).build();

    restAdapter.create(SearchService.class).getCount(StringUtils.EMPTY,
            new Callback<CountContainer>() {

                @Override
                public void success(CountContainer countContainer, Response response) {
                    System.out.println("success");
                }

                @Override
                public void failure(RetrofitError error) {
                    System.out.println("error");
                }
            });

    server.shutdown();

When i use retrofit without callbacks it works.

Do you need to attach your callback *BEFORE* you do `server.play()` ? — Blundell, Jun 30 '14 at 12:30
When I change order, this throws exception java.lang.IllegalStateException: Cannot retrieve port before calling play() — lukjar, Jun 30 '14 at 13:48

score 14 · Accepted Answer · answered Jun 30 '14 at 16:23

14

By having a Callback you are telling Retrofit to invoke the request and call the callback asynchronously. This means that your test is exiting before anything happens.

There are two ways to get this to work:

Use a lock at the end of the test and wait until one of the callback methods are invoked.
Pass an instance of a synchronous Executor (one that just calls .run() immediately) to setExecutors on the RestAdapter.Builder so that the background invocations and callback invocations happen synchronously.

answered Jun 30 '14 at 16:23

Jake Wharton

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+1 thanks, supplying the synchronous `executors` works great. Wouldnt a lock block the main thread and therefore not allow the callbacks to be executed (on the main thread) and therefore the lock never released? By 'lock' im thinking of something like a `CountDownLatch` – Dori Jul 24 '14 at 16:20
This does not work with retrofit 2. How do I make it to work in Retrofit 2? – Rod_Algonquin Sep 15 '16 at 05:28

score 4 · Answer 2 · answered Jul 09 '18 at 04:28

For retrofit 2 see the answer here: https://github.com/square/retrofit/issues/1259 You can supply the synchronous executor to an OkHttpClient (via its dispatcher) and set this client to the Retrofit.Builder. You can also set the same executor to the callbackExecutor.

For example:

CurrentThreadExecutor currentThreadExecutor = new CurrentThreadExecutor();
okhttp3.Dispatcher dispatcher = new okhttp3.Dispatcher(currentThreadExecutor);
OkHttpClient okHttpClient = new 
OkHttpClient.Builder().dispatcher(dispatcher).build();

new Retrofit.Builder()
        .client(okHttpClient)
        .baseUrl(httpUrl)
        .addConverterFactory(JacksonConverterFactory.create())
        .callbackExecutor(currentThreadExecutor)
        .build();

Example of CurrentThreadExecutor implementation: https://gist.github.com/vladimir-bukhtoyarov/38d6b4b277d0a0cfb3af

This should be accepted. Good stuff. – Josh C. Aug 03 '22 at 20:36 — Josh C., Aug 03 '22 at 20:36

score 1 · Answer 3 · answered Aug 05 '19 at 21:31

Alternatively you could use Mockinizer with MockWebServer:

OkHttpClient.Builder()
        .addInterceptor(loggingInterceptor)
        .mockinize(mocks) // <-- just add this line
        .build()

And the requests/responses that you want to mock you can define in the mocks value. In your case it would look something like:

package com.appham.mockinizer.demo

import com.appham.mockinizer.RequestFilter
import okhttp3.mockwebserver.MockResponse

val mocks: Map<RequestFilter, MockResponse> = mapOf(

    RequestFilter("/") to MockResponse().apply {
        setResponseCode(200)
        setBody("""{}""")
    }

)

See https://github.com/donfuxx/Mockinizer

MockWebServer and Retrofit with Callback

3 Answers3

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