dubbo3消费端bean字段名称引发的问题-dubbo2.7升级到dubbo3系列

最近在做老系统升级(springboot2+dubbo2.7.1+zookeeper+nacos-config)，去掉zookeeper的注册中心，替换成nacos2.1版本（阿里云已经不支持1.X版本了）-对应的需要升级springboot和dubbo3。最终升级完成了，其中遇到的诸多问题，能记住多少就总结多少
有在升级过程中，遇到问题的小伙伴，欢迎交流。

报错

这个错误据官方说已经解决了，先看下错误

服务启动时报错：
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'BaClient': Injection of @DubboReference dependencies is failed; nested exception is java.lang.IllegalArgumentException: Can not set com.dubbo3.test.api.AaUserServiceDubbo field com.dubbo3.test.consumer.service.BaClient.userService to com.sun.proxy.$Proxy87
	at org.apache.dubbo.config.spring.beans.factory.annotation.ReferenceAnnotationBeanPostProcessor.postProcessPropertyValues(ReferenceAnnotationBeanPostProcessor.java:326)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1418)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:601)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:524)
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:944)
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583)
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145)
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:758)
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:438)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:337)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1336)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1325)
	at com.xsyx.router.client.ClientApplication.main(ClientApplication.java:16)
Caused by: java.lang.IllegalArgumentException: com.dubbo3.test.api.AaUserServiceDubbo field com.dubbo3.test.consumer.service.BaClient.userService to com.sun.proxy.$Proxy87
	at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:167)
	at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:171)
	at sun.reflect.UnsafeObjectFieldAccessorImpl.set(UnsafeObjectFieldAccessorImpl.java:81)
	at java.lang.reflect.Field.set(Field.java:764)
	at org.apache.dubbo.config.spring.beans.factory.annotation.AbstractAnnotationBeanPostProcessor$AnnotatedInjectElement.inject(AbstractAnnotationBeanPostProcessor.java:470)
	at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:119)
	at org.apache.dubbo.config.spring.beans.factory.annotation.ReferenceAnnotationBeanPostProcessor.postProcessPropertyValues(ReferenceAnnotationBeanPostProcessor.java:322)
	... 17 common frames omitted
修改BaClient AaUserServiceDubbo userService -> AaUserServiceDubbo aaUserServiceDubbo 后启动成功

因为我还有个服务UserServiceDubbo userServiceDubbo

我理解原因是spring在生成bean BaClient的过程中，当赋值属性AaUserServiceDubbo userServiceDubbo时，是根据名称userServiceDubbo查找对应的bean，而不是根据类型AaUserServiceDubbo查找bean，这个是spring的流程，应该不算dubbo的bug

我现在的dubbo版本是3.1.0 ，我看已经在注册时使用rename方式了。这也是要说的第二个问题。
userServiceDubbo#2

已存在bean名称，接口不同名

看看问题

Already exists another bean definition with the same bean name [userServiceDubbo], rename dubbo reference bean to [userServiceDubbo#2]. 
It is recommended to modify the name of one of the beans to avoid injection problems. prev: userServiceDubbo[ReferenceBean:com.dubbo3.test.api.UserServiceDubbo()],
 new: userServiceDubbo#2[ReferenceBean:com.dubbo3.test.api.AaUserServiceDubbo()].
  Please check private com.dubbo3.test.api.AaUserServiceDubbo com.dubbo3.test.consumer.service.CaClient.userServiceDubbo

这个时什么意思呢，简单说，就是，相同的bean 字段名单，但是接口不同名，发现类型不同，注册时，重新命名userServiceDubbo#2

修改下AaUserServiceDubbo aaUserServiceDubbo 就可以了。

可以看下源码：ReferenceAnnotationBeanPostProcessor

 public String registerReferenceBean(String propertyName, Class<?> injectedType, Map<String, Object> attributes, Member member) throws BeansException {

        boolean renameable = true;
        // referenceBeanName
        String referenceBeanName = getAttribute(attributes, ReferenceAttributes.ID);
        if (hasText(referenceBeanName)) {
            renameable = false;
        } else {
            referenceBeanName = propertyName;
        }

        String checkLocation = "Please check " + member.toString();

        // convert annotation props
        ReferenceBeanSupport.convertReferenceProps(attributes, injectedType);

        // get interface
        String interfaceName = (String) attributes.get(ReferenceAttributes.INTERFACE);
        if (StringUtils.isBlank(interfaceName)) {
            throw new BeanCreationException("Need to specify the 'interfaceName' or 'interfaceClass' attribute of '@DubboReference' if enable generic. " + checkLocation);
        }

        // check reference key
        String referenceKey = ReferenceBeanSupport.generateReferenceKey(attributes, applicationContext);

        // find reference bean name by reference key
        List<String> registeredReferenceBeanNames = referenceBeanManager.getBeanNamesByKey(referenceKey);
        if (registeredReferenceBeanNames.size() > 0) {
            // found same name and reference key
            if (registeredReferenceBeanNames.contains(referenceBeanName)) {
                return referenceBeanName;
            }
        }

        //check bean definition
        if (beanDefinitionRegistry.containsBeanDefinition(referenceBeanName)) {
            BeanDefinition prevBeanDefinition = beanDefinitionRegistry.getBeanDefinition(referenceBeanName);
            String prevBeanType = prevBeanDefinition.getBeanClassName();
            String prevBeanDesc = referenceBeanName + "[" + prevBeanType + "]";
            String newBeanDesc = referenceBeanName + "[" + referenceKey + "]";

            if (isReferenceBean(prevBeanDefinition)) {
                //check reference key
                String prevReferenceKey = ReferenceBeanSupport.generateReferenceKey(prevBeanDefinition, applicationContext);
                if (StringUtils.isEquals(prevReferenceKey, referenceKey)) {
                    //found matched dubbo reference bean, ignore register
                    return referenceBeanName;
                }
                //get interfaceName from attribute
                Assert.notNull(prevBeanDefinition, "The interface class of ReferenceBean is not initialized");
                prevBeanDesc = referenceBeanName + "[" + prevReferenceKey + "]";
            }

            // bean name from attribute 'id' or java-config bean, cannot be renamed
            if (!renameable) {
                throw new BeanCreationException("Already exists another bean definition with the same bean name [" + referenceBeanName + "], " +
                    "but cannot rename the reference bean name (specify the id attribute or java-config bean), " +
                    "please modify the name of one of the beans: " +
                    "prev: " + prevBeanDesc + ", new: " + newBeanDesc + ". " + checkLocation);
            }

            // the prev bean type is different, rename the new reference bean
            int index = 2;
            String newReferenceBeanName = null;
            while (newReferenceBeanName == null || beanDefinitionRegistry.containsBeanDefinition(newReferenceBeanName)
                || beanDefinitionRegistry.isAlias(newReferenceBeanName)) {
                newReferenceBeanName = referenceBeanName + "#" + index;
                index++;
                // double check found same name and reference key
                if (registeredReferenceBeanNames.contains(newReferenceBeanName)) {
                    return newReferenceBeanName;
                }
            }
            newBeanDesc = newReferenceBeanName + "[" + referenceKey + "]";

            logger.warn("Already exists another bean definition with the same bean name [" + referenceBeanName + "], " +
                "rename dubbo reference bean to [" + newReferenceBeanName + "]. " +
                "It is recommended to modify the name of one of the beans to avoid injection problems. " +
                "prev: " + prevBeanDesc + ", new: " + newBeanDesc + ". " + checkLocation);
            referenceBeanName = newReferenceBeanName;
        }
        attributes.put(ReferenceAttributes.ID, referenceBeanName);

        // If registered matched reference before, just register alias
        if (registeredReferenceBeanNames.size() > 0) {
            beanDefinitionRegistry.registerAlias(registeredReferenceBeanNames.get(0), referenceBeanName);
            referenceBeanManager.registerReferenceKeyAndBeanName(referenceKey, referenceBeanName);
            return referenceBeanName;
        }

        Class interfaceClass = injectedType;

        // TODO Only register one reference bean for same (group, interface, version)

        // Register the reference bean definition to the beanFactory
        RootBeanDefinition beanDefinition = new RootBeanDefinition();
        beanDefinition.setBeanClassName(ReferenceBean.class.getName());
        beanDefinition.getPropertyValues().add(ReferenceAttributes.ID, referenceBeanName);

        // set attribute instead of property values
        beanDefinition.setAttribute(Constants.REFERENCE_PROPS, attributes);
        beanDefinition.setAttribute(ReferenceAttributes.INTERFACE_CLASS, interfaceClass);
        beanDefinition.setAttribute(ReferenceAttributes.INTERFACE_NAME, interfaceName);

        // create decorated definition for reference bean, Avoid being instantiated when getting the beanType of ReferenceBean
        // see org.springframework.beans.factory.support.AbstractBeanFactory#getTypeForFactoryBean()
        GenericBeanDefinition targetDefinition = new GenericBeanDefinition();
        targetDefinition.setBeanClass(interfaceClass);
        beanDefinition.setDecoratedDefinition(new BeanDefinitionHolder(targetDefinition, referenceBeanName + "_decorated"));

        // signal object type since Spring 5.2
        beanDefinition.setAttribute(Constants.OBJECT_TYPE_ATTRIBUTE, interfaceClass);

        beanDefinitionRegistry.registerBeanDefinition(referenceBeanName, beanDefinition);
        referenceBeanManager.registerReferenceKeyAndBeanName(referenceKey, referenceBeanName);
        logger.info("Register dubbo reference bean: " + referenceBeanName + " = " + referenceKey + " at " + member);
        return referenceBeanName;
    }