Spring Cloud Stream和@Publisher注释的兼容性 [英] Spring Cloud Stream and @Publisher annotation compatiblity

问题描述

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)，因此我尝试为此目的使用Spring Integration注释，即@Publisher.

Since Spring Cloud Stream has not an annotation for sending a new message to a stream (@SendTo only works when @StreamListener is declared), I tried to use Spring Integration annotation for that purpose, that is @Publisher.

由于@Publisher需要一个频道，并且Spring Cloud Stream的@EnableBinding批注可以使用@Output批注绑定输出频道，因此我尝试通过以下方式对其进行混合:

Because @Publisher takes a channel and @EnableBinding annotations of Spring Cloud Stream can bind an output channel using @Output annotation, I tried to mix them in the following way:

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

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

此外，我在配置文件中声明了@EnablePublisher批注:

Also, I declared @EnablePublisher annotation in a configuration file:

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

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

我的测试:

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

    @Autowired
    private ExampleService exampleService;

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

但是我遇到了以下错误:

But I'm getting the following error:

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'

这里的问题是不能插入ExampleService bean.

Problem here is that ExampleService bean can not be injected.

任何人都知道我该如何做这项工作?

Anyone knows how can I make this work?

谢谢！

推荐答案

由于在ExampleService中使用了@Publisher批注，因此该批注将作为该发布内容的代理.

Since you use a @Publisher annotation in your ExampleService, it is proxied for that publishing stuff.

解决该问题的唯一方法是公开ExampleService的接口，并将该接口注入到您的测试类中:

Only the way to overcome the issue is to expose an interface for your ExampleService and inject already that one into your test class:

public interface ExampleServiceInterface {

     String sendMessage(String message);

}

...

public class ExampleService implements ExampleServiceInterface {

...


@Autowired
private ExampleServiceInterface exampleService;

另一方面，您的ExampleService.sendMessage()似乎不对消息进行任何操作，因此您可以考虑在某些界面上使用@MessagingGateway:

On the other hand it looks like your ExampleService.sendMessage() does nothing with the message, so you may consider to use a @MessagingGateway on some interface instead: https://docs.spring.io/spring-integration/reference/html/messaging-endpoints-chapter.html#gateway

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