API-First with AsyncAPI and ZenWave SDK

1// Autogenerated: you can @Autowire it in your code
2public interface ICustomerEventsProducer {
3    // headers object omitted for brevity
4    /**
5     * Customer Domain Events
6     */
7    boolean onCustomerEvent(CustomerEventPayload payload, CustomerEventPayloadHeaders headers);
8
9}

1// Autogenerated: add it to your autoscan packages
2@Component
3public class CustomerEventsProducer implements ICustomerEventsProducer {
4    
5    // details omitted for brevity
6    
7    /**
8     * Customer Domain Events
9     */
10    public boolean onCustomerEvent(CustomerEventPayload payload, CustomerEventPayloadHeaders headers) {
11        // this is one of the many flavors, you shouldn't need to worry about the details
12        log.debug("Sending message to topic: {}", onCustomerEventBindingName);
13        Message message = MessageBuilder.createMessage(payload, new MessageHeaders(headers));
14        return streamBridge.send(onCustomerEventBindingName, message);
15    }
16}

1// Autowire this producer in your code
2@Autowired
3ICustomerEventsProducer customerEventsProducer;
4
5// and use it to produce messages
6var message = new CustomerEventPayload()
7        .withCustomerId("123")
8        // [...] set some more data
9        .withEventType(CustomerEventPayload.EventType.CREATED);
10// notice how headers are also strongly typed
11var headers = new ICustomerEventsProducer.CustomerEventPayloadHeaders()
12        .entityId("123")
13        .commonHeader("value")
14        .set("undocumented-header", "value");
15
16customerEventsProducer.onCustomerEvent(message, headers);

1// Autogenerated: you need to implement and provide this business interface
2public interface IOnCustomerEventConsumerService {
3    /**
4     * Customer Domain Events
5     */
6    default void onCustomerEvent(CustomerEventPayload payload, CustomerEventPayloadHeaders headers) {};
7}

1// Autogenerated: add it to your autoscan packages and provide business interface implementation
2@Component("on-customer-event")
3public class OnCustomerEventConsumer implements Consumer<Message<CustomerEventPayload>> {
4
5    // you need to implement this interface
6    protected IOnCustomerEventConsumerService service;
7
8    @Override
9    public void accept(Message<CustomerEventPayload> message) {
10        log.debug("Received message: {}", message);
11        try {
12            Object payload = message.getPayload();
13            if (payload instanceof CustomerEventPayload) {
14                var headers = new IOnCustomerEventConsumerService.CustomerEventPayloadHeaders();
15                headers.putAll(message.getHeaders());
16                service.onCustomerEvent((CustomerEventPayload) payload, headers);
17                return;
18            }
19            log.error("Received message without any business handler: [payload: {}, message: {}]", payload.getClass().getName(), message);
20        } catch (Exception e) {
21            // error handling and dead-letter-queue routing omitted for brevity
22        }
23    }
24}

1// Implement the business interface and add it to your context
2@Component
3class DoCustomerRequestConsumerService implements IDoCustomerRequestConsumerService {
4
5    @Override
6    public void doCustomerRequest(CustomerRequestPayload payload, CustomerRequestPayloadHeaders headers) {
7        log.info("Received '{}' message with payload: {}", payload.getClass(), payload);
8        // [...] do something with this message
9    }
10}

1    @Bean("myTracingIdSupplier")
2    public Supplier tracingIdSupplier() {
3        return () -> "test-tracing-id";
4    }

1// generated class, you can use in your tests
2public class ProducerInMemoryContext {
3
4    public static final ProducerInMemoryContext INSTANCE = new ProducerInMemoryContext();
5
6
7    private CustomerEventsProducerCaptor customerEventsProducerCaptor = new CustomerEventsProducerCaptor();
8
9    public <T extends ICustomerEventsProducer> T customerEventsProducer() {
10        return (T) customerEventsProducerCaptor;
11    }
12}

1// example of how you can instantiate your service using the in-memory producer captor
2public class InMemoryTestsManualContext extends InMemoryTestsConfig {
3
4    // [...] other beans omitted for brevity
5    
6    public CustomerUseCasesImpl customerUseCases() {
7        // instantiating a bean with in-memory dependencies
8        return new CustomerUseCasesImpl(customerRepository(), ProducerInMemoryContext.INSTANCE.customerEventsProducer());
9    }
10}
11
12// and using it in your tests to perform assertions
13public class CustomerUseCasesTest {
14    
15    // this is the in-memory producer captor wired
16    CustomerEventsProducerCaptor customerEventsProducer = ProducerInMemoryContext.INSTANCE.customerEventsProducer();
17
18    @Test
19    void testCustomerUseCase() {
20        // [...] test your use case
21        Assertions.assertEquals(3, customerEventsProducer.getCapturedMessages(customerEventsProducer.onCustomerEventBindingName).size());
22    }
23}