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Spring Cloud Stream与@Publisher注释的兼容性

spring-cloud-stream spring-cloud spring-integration spring-boot spring

italktothewind · 技术社区 · 7 年前

由于Spring Cloud Stream没有用于向流发送新消息的注释(@SendTo仅在声明@StreamListener时有效),因此我尝试使用Spring集成注释,即@Publisher。

因为@Publisher接受一个通道,Spring Cloud Stream的@EnableBinding注释可以使用@output annotation绑定一个输出通道,所以我尝试用以下方式混合它们:

@EnableBinding(MessageSource.class)
@Service
public class ExampleService {

    @Publisher(channel = MessageSource.OUTPUT)
    public String sendMessage(String message){
        return message;
    }
}

此外,我还在配置文件中声明了@EnablePublisher注释:

@SpringBootApplication
@EnablePublisher("")
public class ExampleApplication {

    public static void main(String[] args){
        SpringApplication.run(ExampleApplication.class, args);
    }
}

@RunWith(SpringRunner.class)
@SpringBootTest
public class ExampleServiceTest {

    @Autowired
    private ExampleService exampleService;

    @Test
    public void testQueue(){
        exampleService.queue("Hi!");
        System.out.println("Ready!");
    }
}

但我得到了以下错误:

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'com.example.ExampleServiceTest': Unsatisfied dependency expressed through field 'exampleService'; nested exception is 
org.springframework.beans.factory.BeanNotOfRequiredTypeException: Bean named 'exampleService' is expected to be of type 'com.example.ExampleService' but was actually of type 'com.sun.proxy.$Proxy86'

这里的问题是exampleServicebean不能被注入。

谢谢

1 回复 | 直到 7 年前

Artem Bilan 7 年前

因为你用的是 @Publisher 在您的 ExampleService

解决此问题的唯一方法是为您的应用程序公开一个接口并将其注入到测试类中:

public interface ExampleServiceInterface {

     String sendMessage(String message);

}

...

public class ExampleService implements ExampleServiceInterface {

...


@Autowired
private ExampleServiceInterface exampleService;

另一方面,它看起来像你的 ExampleService.sendMessage() @MessagingGateway 而在某些界面上: https://docs.spring.io/spring-integration/reference/html/messaging-endpoints-chapter.html#gateway

Michael Ouyang 6 年前

为什么不直接手动将消息发送到流,如下所示。

@Component
@Configuration
@EnableBinding(Processor.class)
public class Sender {

    @Autowired
    private Processor processor;

    public void send(String message) {

        processor.output().send(MessageBuilder.withPayload(message).build());

    }

}

您可以通过测试仪进行测试。

@SpringBootTest
public class SenderTest {

    @Autowired
    private MessageCollector messageCollector;

    @Autowired
    private Processor processor;

    @Autowired
    private Sender sender;

    @SuppressWarnings("unchecked")
    @Test
    public void testSend() throws Exception{

        sender.send("Hi!");
        Message<String> message = (Message<String>) this.messageCollector.forChannel(this.processor.output()).poll(1, TimeUnit.SECONDS);
        String messageData = message.getPayload().toString();
        System.out.println(messageData);

    }

}

您应该在控制台中看到“嗨!”。