Springcloud Stream 整合rabbitmq报错

出现bug:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sendMessageController': Injection of resource dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'IMessageProviderImpl': Injection of resource dependencies failed; nested exception is org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type 'org.springframework.messaging.MessageChannel' available: expected single matching bean but found 3: output,nullChannel,errorChannel
	at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessProperties(CommonAnnotationBeanPostProcessor.java:321) ~[spring-context-5.3.6.jar:5.3.6]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1413) ~[spring-beans-5.3.6.jar:5.3.6]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:601) ~[spring-beans-5.3.6.jar:5.3.6]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:524) ~[spring-beans-5.3.6.jar:5.3.6]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.6.jar:5.3.6]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.6.jar:5.3.6]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.6.jar:5.3.6]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.6.jar:5.3.6]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:944) ~[spring-beans-5.3.6.jar:5.3.6]
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918) ~[spring-context-5.3.6.jar:5.3.6]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583) ~[spring-context-5.3.6.jar:5.3.6]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:144) ~[spring-boot-2.4.5.jar:2.4.5]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:782) [spring-boot-2.4.5.jar:2.4.5]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:774) [spring-boot-2.4.5.jar:2.4.5]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:439) [spring-boot-2.4.5.jar:2.4.5]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:339) [spring-boot-2.4.5.jar:2.4.5]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1340) [spring-boot-2.4.5.jar:2.4.5]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1329) [spring-boot-2.4.5.jar:2.4.5]
	at com.albertchan.springcloud.StreamMQMain8801.main(StreamMQMain8801.java:13) [classes/:na]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_241]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_241]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_241]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_241]
	at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-2.4.5.jar:2.4.5]
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'IMessageProviderImpl': Injection of resource dependencies failed; nested exception is org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type 'org.springframework.messaging.MessageChannel' available: expected single matching bean but found 3: output,nullChannel,errorChannel
	at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessProperties(CommonAnnotationBeanPostProcessor.java:321) ~[spring-context-5.3.6.jar:5.3.6]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1413) ~[spring-beans-5.3.6.jar:5.3.6]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:601) ~[spring-beans-5.3.6.jar:5.3.6]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:524) ~[spring-beans-5.3.6.jar:5.3.6]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.6.jar:5.3.6]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.6.jar:5.3.6]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.6.jar:5.3.6]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.6.jar:5.3.6]
	at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.3.6.jar:5.3.6]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1380) ~[spring-beans-5.3.6.jar:5.3.6]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1300) ~[spring-beans-5.3.6.jar:5.3.6]
	at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.autowireResource(CommonAnnotationBeanPostProcessor.java:521) ~[spring-context-5.3.6.jar:5.3.6]
	at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.getResource(CommonAnnotationBeanPostProcessor.java:497) ~[spring-context-5.3.6.jar:5.3.6]
	at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor$ResourceElement.getResourceToInject(CommonAnnotationBeanPostProcessor.java:650) ~[spring-context-5.3.6.jar:5.3.6]
	at org.springframework.beans.factory.annotation.InjectionMetadata$InjectedElement.inject(InjectionMetadata.java:228) ~[spring-beans-5.3.6.jar:5.3.6]
	at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:119) ~[spring-beans-5.3.6.jar:5.3.6]
	at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessProperties(CommonAnnotationBeanPostProcessor.java:318) ~[spring-context-5.3.6.jar:5.3.6]
	... 23 common frames omitted
Caused by: org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type 'org.springframework.messaging.MessageChannel' available: expected single matching bean but found 3: output,nullChannel,errorChannel
	at org.springframework.beans.factory.config.DependencyDescriptor.resolveNotUnique(DependencyDescriptor.java:220) ~[spring-beans-5.3.6.jar:5.3.6]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1358) ~[spring-beans-5.3.6.jar:5.3.6]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1300) ~[spring-beans-5.3.6.jar:5.3.6]
	at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.autowireResource(CommonAnnotationBeanPostProcessor.java:521) ~[spring-context-5.3.6.jar:5.3.6]
	at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.getResource(CommonAnnotationBeanPostProcessor.java:497) ~[spring-context-5.3.6.jar:5.3.6]
	at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor$ResourceElement.getResourceToInject(CommonAnnotationBeanPostProcessor.java:650) ~[spring-context-5.3.6.jar:5.3.6]
	at org.springframework.beans.factory.annotation.InjectionMetadata$InjectedElement.inject(InjectionMetadata.java:228) ~[spring-beans-5.3.6.jar:5.3.6]
	at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:119) ~[spring-beans-5.3.6.jar:5.3.6]
	at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessProperties(CommonAnnotationBeanPostProcessor.java:318) ~[spring-context-5.3.6.jar:5.3.6]
	... 39 common frames omitted

自己学习周阳老师的springcloud stream 的时候出现的小bug觉得有必要和大家分享一下。

直接说问题所在，我们看到这个上述报错，就会很纳闷，明明自己照着视频做的，反而会报错o(╥﹏╥)o。一般来说，上面的问题要么就是我们的依赖出现了冲突，要么就是我们的配置文件写错了，要么就是某一个和配置文件有关系的变量写错了。

1.检查依赖

自己比较粗心，在检查依赖的时候发现自己还加了和数据库有关的依赖。。。。

2.检查配置文件

server:
  port: 8801

spring:
#  rabbitmq:
#    host: 192.168.68.4
#    port: 5672
#    username: guest
#    password: guest
#    virtual-host: /
  cloud:
    stream:
      binders:
        defaultRabbit:
          type: rabbit
          environment:
            spring:
              rabbitmq:
                host: xxxxxx #自己的服务器或者localhost都行
                port: 5672
                username: admin
                password: admin
                virtualhost: /
      bindings:
        output:
          destination: studyExchange
          content-type: application/json
          binder: defaultRabbit

eureka:
  client: #客户端进行Eureka注册的配置
    service-url:
      defaultZone: http://localhost:7001/eureka
  instance:
    lease-expiration-duration-in-seconds: 5 #如果现在超过了5秒的间隔，默认90秒
    lease-renewal-interval-in-seconds: 2  #设置心跳时间间隔，默认是30秒
    instance-id: send-8801.com
    prefer-ip-address: true

3.最终错误所在

看完配置文件，提示又说无法注册接口实体类，定睛一看发现自己的MessageChanel 对象的名字不和配置文件一样！！！

所以这里改成output就可以了

总结: 写代码的时候，还是要沉下心来，一步一步来，小bug大问题，一改就是一个晚上（一杯茶一包烟，一个bug改一天~~~），这里我的错误希望可以帮到大家。