SpringCloud alibaba 配置Nacos后控制台报错, 但是程序可以正常运行问题

异常信息

SpringCloud alibaba 配置Nacos启动服务后，会报错
具体异常信息:

com.alibaba.nacos.api.exception.NacosException: java.lang.reflect.InvocationTargetException
	at com.alibaba.nacos.api.config.ConfigFactory.createConfigService(ConfigFactory.java:45) ~[nacos-api-1.1.1.jar:na]
	at com.alibaba.nacos.api.NacosFactory.createConfigService(NacosFactory.java:43) ~[nacos-api-1.1.1.jar:na]
	at com.alibaba.cloud.nacos.NacosConfigProperties.configServiceInstance(NacosConfigProperties.java:346) ~[spring-cloud-alibaba-nacos-config-2.1.0.RELEASE.jar:2.1.0.RELEASE]
	at com.alibaba.cloud.nacos.NacosConfigAutoConfiguration.nacosContextRefresher(NacosConfigAutoConfiguration.java:64) [spring-cloud-alibaba-nacos-config-2.1.0.RELEASE.jar:2.1.0.RELEASE]
	at com.alibaba.cloud.nacos.NacosConfigAutoConfiguration$$EnhancerBySpringCGLIB$$eff9e4ef.CGLIB$nacosContextRefresher$3(<generated>) [spring-cloud-alibaba-nacos-config-2.1.0.RELEASE.jar:2.1.0.RELEASE]
	at com.alibaba.cloud.nacos.NacosConfigAutoConfiguration$$EnhancerBySpringCGLIB$$eff9e4ef$$FastClassBySpringCGLIB$$d0d0e3ba.invoke(<generated>) [spring-cloud-alibaba-nacos-config-2.1.0.RELEASE.jar:2.1.0.RELEASE]
	at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:244) [spring-core-5.3.18.jar:5.3.18]
	at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:331) [spring-context-5.3.18.jar:5.3.18]
	at com.alibaba.cloud.nacos.NacosConfigAutoConfiguration$$EnhancerBySpringCGLIB$$eff9e4ef.nacosContextRefresher(<generated>) [spring-cloud-alibaba-nacos-config-2.1.0.RELEASE.jar:2.1.0.RELEASE]
	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.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) [spring-beans-5.3.18.jar:5.3.18]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:653) [spring-beans-5.3.18.jar:5.3.18]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:638) [spring-beans-5.3.18.jar:5.3.18]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1352) [spring-beans-5.3.18.jar:5.3.18]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1195) [spring-beans-5.3.18.jar:5.3.18]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:582) [spring-beans-5.3.18.jar:5.3.18]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) [spring-beans-5.3.18.jar:5.3.18]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) [spring-beans-5.3.18.jar:5.3.18]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.18.jar:5.3.18]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) [spring-beans-5.3.18.jar:5.3.18]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) [spring-beans-5.3.18.jar:5.3.18]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:953) ~[spring-beans-5.3.18.jar:5.3.18]
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918) ~[spring-context-5.3.18.jar:5.3.18]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583) ~[spring-context-5.3.18.jar:5.3.18]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.6.6.jar:2.6.6]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:740) ~[spring-boot-2.6.6.jar:2.6.6]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:415) ~[spring-boot-2.6.6.jar:2.6.6]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:303) ~[spring-boot-2.6.6.jar:2.6.6]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1312) ~[spring-boot-2.6.6.jar:2.6.6]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1301) ~[spring-boot-2.6.6.jar:2.6.6]
	at com.tytk.xylb.thirdparty.XylbTestApplication.main(XylbTestApplication.java:13) ~[classes/:na]
Caused by: java.lang.reflect.InvocationTargetException: null
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_241]
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_241]
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_241]
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_241]
	at com.alibaba.nacos.api.config.ConfigFactory.createConfigService(ConfigFactory.java:42) ~[nacos-api-1.1.1.jar:na]
	... 33 common frames omitted
Caused by: com.alibaba.nacos.api.exception.NacosException: endpoint is blank
	at com.alibaba.nacos.client.config.impl.ServerListManager.<init>(ServerListManager.java:154) ~[nacos-client-1.1.1.jar:na]
	at com.alibaba.nacos.client.config.http.ServerHttpAgent.<init>(ServerHttpAgent.java:244) ~[nacos-client-1.1.1.jar:na]
	at com.alibaba.nacos.client.config.NacosConfigService.<init>(NacosConfigService.java:83) ~[nacos-client-1.1.1.jar:na]
	... 38 common frames omitted

相关的application.yml配置文件如下:

server:
  port: 9003
spring:
  application:
    name: xylb-test
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848 #配置Nacos地址

异常处理

这种写法，服务是可以正常启动的，不过，每次启动服务都会看到这堆报错，看着挺闹心。将上述配置的一部分，调整并迁移到bootstrap.yml中

spring:
  application:
    name: xylb-test
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848 #配置Nacos地址
      config:
        server-addr: 127.0.0.1:8848 #Nacos地址
        file-extension: yaml #这里我们获取的yaml格式的配置

重新启动服务，则不会报错了

异常分析

上面的报错，有两个原因。
一是没有在配置文件中声明配置中心(spring.cloud.nacos.config.server-addr)。
二是项目初始化时，读取不到配置(需要将部分配置放置到bootstrap配置文件中)。

bootstrap.yml vs application.yml

下面补充一下application.yml和bootstrap.yml的主要区别 bootstrap.yml 和 application.yml 都可以用来配置参数。

bootstrap.yml 用来程序引导时执行，应用于更加早期配置信息读取。可以理解成系统级别的一些参数配置，这些参数一般是不会变动的。

application.yml 可以用来定义应用级别的， 应用程序特有配置信息，可以用来配置后续各个模块中需使用的公共参数等。如果搭配 spring-cloud-config 使用， application.yml里面定义的文件可以实现动态替换。