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首页 > 解决方案 > 用他们的 test-binder 测试 spring-cloud-stream 总是抛出 MessageDeliveryException: Dispatcher has no subscribers for channel

testing - 用他们的 test-binder 测试 spring-cloud-stream 总是抛出 MessageDeliveryException: Dispatcher has no subscribers for channel

问题描述

我正在尝试为我的消息生产者编写测试。但是每当我尝试使用注入的绑定发送消息时，我都会收到以下错误

Caused by: org.springframework.integration.MessageDispatchingException: Dispatcher has no subscribers, failedMessage=GenericMessage [payload=..., headers={spanTraceId=0761b2d61b665041, spanId=e3b298682fefe198, spanParentSpanId=549ea87126d2484d, nativeHeaders={X-B3-TraceId=[0761b2d61b665041], spanTraceId=[0761b2d61b665041], X-B3-SpanId=[e3b298682fefe198], spanId=[e3b298682fefe198], X-B3-ParentSpanId=[549ea87126d2484d], spanParentSpanId=[549ea87126d2484d], X-B3-Sampled=[0], spanSampled=[0]}, X-B3-SpanId=e3b298682fefe198, X-B3-ParentSpanId=549ea87126d2484d, X-B3-Sampled=0, X-B3-TraceId=0761b2d61b665041, id=0c885a37-a1b1-fc0a-1314-e403ec1bffdb, spanSampled=0, contentType=application/json, timestamp=1589551815143}]
    at org.springframework.integration.dispatcher.UnicastingDispatcher.doDispatch(UnicastingDispatcher.java:138)
    at org.springframework.integration.dispatcher.UnicastingDispatcher.dispatch(UnicastingDispatcher.java:105)
    at org.springframework.integration.channel.AbstractSubscribableChannel.doSend(AbstractSubscribableChannel.java:73)
    ... 42 more

由于我正在测试消息生产者，因此我的代码中自然没有消费者。我该如何解决这个异常？

这是我创建的一个最小测试类，它显示了相同的行为：

@RunWith(SpringRunner.class)
@ActiveProfiles("test")
@SpringBootTest(classes = {MessagingTest.SampleConfiguration.class, Application.class, EventMockConfiguration.class})
public class MessagingTest {

    @Autowired
    private LibraryMessageSource libraryMessageSource;

    @Autowired
    private InputDestination input;

    @Autowired
    private OutputDestination output;

    @Test
    public void test() throws Exception {
        libraryMessageSource.creations().send(MessageBuilder.withPayload("test").build());
    }

    @SpringBootApplication
    @Import({TestChannelBinderConfiguration.class})
    public static class SampleConfiguration {

    }
}

注意：Application.class 是我的应用程序和 EventMock 的主类，它使用特定的模拟覆盖上下文中的 bean。

public interface LibraryMessageSource {

    String LIBRARY_CREATE = "messages-library-create";
    String LIBRARY_UPDATE = "messages-library-update";

    @Input(LIBRARY_CREATE)
    MessageChannel creations();

    @Input(LIBRARY_UPDATE)
    MessageChannel updates();
}

标签： testingspring-cloudspring-cloud-streamspring-messaging

解决方案

因为我正在测试消息生产者

您的应用程序有消费者，而不是生产者

    @Input(INPUT)
    MessageChannel events();

你还没有@StreamListener订阅它。

    @Test
    public void test() throws Exception {
        libraryMessageSource.events().send(MessageBuilder.withPayload("test").build());
    }

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