1. 确保mockwebserver运行在一个单独的线程中，这样它不会阻塞UI线程。

@Rule
public final ExecutorServiceRule executorServiceRule = new ExecutorServiceRule();
private MockWebServer server;

@Before
public void setUp() throws Exception {
    server = new MockWebServer();
    server.start();
}

public void testMyUi() throws Exception {
    server.enqueue(new MockResponse().setBody("hello, world!"));
    onView(withId(R.id.my_button)).perform(click());
    RecordedRequest request = server.takeRequest();
    assertThat(request.getPath(), equalTo("/hello"));
}

2. 如果您发现您的UI测试在MockWebServer启动后仍然失败，那么您可能需要使用idling资源来等待服务器响应。

@Test
public void testMyUi() throws Exception {
    server.enqueue(new MockResponse().setBody("hello, world!"));
    onView(withId(R.id.my_button)).perform(click());
    // Wait until the server has received the request, 
    // fired the callback, and delivered the response.
    IdlingResource idlingResource = OkHttp3IdlingResource.create("OkHttp", client);
    IdlingRegistry.getInstance().register(idlingResource);
    try {
        RecordedRequest request = server.takeRequest();
        assertThat(request.getPath(), equalTo("/hello"));
    } finally {
        IdlingRegistry.getInstance().unregister(idlingResource);
    }
}