Spring Integration wiretap direct MessageChannel for Testing

Question

I want to do an integration test of two Spring Boot apps which are also using Spring Integration flows. To test my apps, I want to check the messages routed through myMessageChannel. It is defined in an XML flow in one of the applications.

How do I wiretap into my direct message channel and redirect the messages to a PollableChannel, so I can read them one by one? None of the methods I found online worked for me.

@RunWith(SpringRunner.class)
@SpringBootTest(classes = {App1.class, App2.class}, webEnvironment = SpringBootTest.WebEnvironment.DEFINED_PORT)
@TestPropertySource("classpath:integration.properties")
public class MyWireTapTest {

    @Autowired
    MessageChannel myMessageChannel;

    @Test
    public void test() {


        // This is basically what I want to do
        // But it does not work, since it is a direct channel
        myMessageChannel.recieve();

    }
}

Answer 1

Autowire it as AbstractMessageChannel and use

myMessageChannel.addInterceptor(new WireTap(tapChannel));