spring boot、spring cloud、spring cloud alibaba、nacos之间的版本对应

1、刚开始，我的spring cloud alibaba的版本为2.1.0，nacos版本为1.4.1

<com.alibaba.cloud>2.1.0.RELEASE</com.alibaba.cloud>

然后报错如下：

***************************
APPLICATION FAILED TO START
***************************

Description:

Failed to configure a DataSource: 'url' attribute is not specified and no embedded datasource could be configured.

Reason: Failed to determine a suitable driver class


Action:

Consider the following:
    If you want an embedded database (H2, HSQL or Derby), please put it on the classpath.
    If you have database settings to be loaded from a particular profile you may need to activate it (no profiles are currently active).

说明没有读取到nacos中的配置，nacos中的配置如下：

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/leadnews_user?useUnicode=true&characterEncoding=UTF-8&serverTimezone=UTC&useoldAliasMetadataBehavior=true&allowMultiQueries=true
    username: root
    password: 123456
# 设置Mapper接口所对应的XML文件位置，如果你在Mapper接口中有自定义方法，需要进行该配置
mybatis-plus:
  mapper-locations: classpath*:mapper/*.xml
  # 设置别名包扫描路径，通过该属性可以给包中的类注册别名
  type-aliases-package: com.heima.model.user.pojos

2、后来将spring cloud alibaba的版本由2.1.0改为2.2.0，就能读取nacos中的配置了。

<com.alibaba.cloud>2.2.0.RELEASE</com.alibaba.cloud>

此时springcloud版本为Hoxton.RELEASE，

3、如果此时将springcloud版本改为Greenwich.RELEASE，启动失败，报错如下：

java.lang.IllegalArgumentException: Could not find class [org.springframework.cloud.client.discovery.composite.reactive.ReactiveCompositeDiscoveryClientAutoConfiguration]
    at org.springframework.util.ClassUtils.resolveClassName(ClassUtils.java:327)
    at org.springframework.core.annotation.TypeMappedAnnotation.adapt(TypeMappedAnnotation.java:483)
    at org.springframework.core.annotation.TypeMappedAnnotation.getValue(TypeMappedAnnotation.java:403)
    at org.springframework.core.annotation.TypeMappedAnnotation.asMap(TypeMappedAnnotation.java:288)
    at org.springframework.core.annotation.AbstractMergedAnnotation.asAnnotationAttributes(AbstractMergedAnnotation.java:193)
    at org.springframework.core.type.AnnotatedTypeMetadata.getAnnotationAttributes(AnnotatedTypeMetadata.java:106)
    at org.springframework.context.annotation.AnnotationConfigUtils.attributesFor(AnnotationConfigUtils.java:285)
    at org.springframework.context.annotation.AnnotationBeanNameGenerator.determineBeanNameFromAnnotation(AnnotationBeanNameGenerator.java:100)
    at org.springframework.context.annotation.AnnotationBeanNameGenerator.generateBeanName(AnnotationBeanNameGenerator.java:79)
    at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.registerBeanDefinitionForImportedConfigurationClass(ConfigurationClassBeanDefinitionReader.java:160)
    at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitionsForConfigurationClass(ConfigurationClassBeanDefinitionReader.java:141)
    at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitions(ConfigurationClassBeanDefinitionReader.java:120)
    at org.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigBeanDefinitions(ConfigurationClassPostProcessor.java:337)
    at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(ConfigurationClassPostProcessor.java:242)
    at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanDefinitionRegistryPostProcessors(PostProcessorRegistrationDelegate.java:275)
    at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:95)
    at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:706)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:532)
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:747)
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:315)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1215)
    at com.heima.user.UserApplication.main(UserApplication.java:20)
Caused by: java.lang.ClassNotFoundException: org.springframework.cloud.client.discovery.composite.reactive.ReactiveCompositeDiscoveryClientAutoConfiguration
    at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:418)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:355)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:348)
    at org.springframework.util.ClassUtils.forName(ClassUtils.java:277)
    at org.springframework.util.ClassUtils.resolveClassName(ClassUtils.java:317)
    ... 24 common frames omitted
2022-08-01 10:05:38.015 [main] DEBUG o.s.b.w.s.c.AnnotationConfigServletWebServerApplicationContext - Closing org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@765df79d, started on Mon Aug 01 10:05:37 CST 2022, parent: org.springframework.context.annotation.AnnotationConfigApplicationContext@5be067de

此时，我的springboot版本为2.2.1.RELEASE。

4、如果我将springboot版本改为2.1.0，发现报错：

2022-08-01 09:59:01.796 [main] ERROR o.s.boot.SpringApplication - Application run failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'bootstrapImportSelectorConfiguration': Initialization of bean failed; nested exception is java.lang.NoClassDefFoundError: org/springframework/boot/context/properties/ConfigurationPropertiesBean
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:584)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:498)
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:846)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:863)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:546)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775)
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:316)
    at org.springframework.boot.builder.SpringApplicationBuilder.run(SpringApplicationBuilder.java:139)
    at org.springframework.cloud.bootstrap.BootstrapApplicationListener.bootstrapServiceContext(BootstrapApplicationListener.java:206)
    at org.springframework.cloud.bootstrap.BootstrapApplicationListener.onApplicationEvent(BootstrapApplicationListener.java:117)
    at org.springframework.cloud.bootstrap.BootstrapApplicationListener.onApplicationEvent(BootstrapApplicationListener.java:74)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:127)
    at org.springframework.boot.context.event.EventPublishingRunListener.environmentPrepared(EventPublishingRunListener.java:75)
    at org.springframework.boot.SpringApplicationRunListeners.environmentPrepared(SpringApplicationRunListeners.java:54)
    at org.springframework.boot.SpringApplication.prepareEnvironment(SpringApplication.java:347)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:306)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1248)
    at com.heima.user.UserApplication.main(UserApplication.java:20)
Caused by: java.lang.NoClassDefFoundError: org/springframework/boot/context/properties/ConfigurationPropertiesBean
    at org.springframework.cloud.context.properties.ConfigurationPropertiesBeans.postProcessBeforeInitialization(ConfigurationPropertiesBeans.java:94)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization(AbstractAutowireCapableBeanFactory.java:419)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1737)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:576)
    ... 26 common frames omitted
Caused by: java.lang.ClassNotFoundException: org.springframework.boot.context.properties.ConfigurationPropertiesBean
    at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:418)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:355)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
    ... 30 common frames omitted

综上所述：要想读取nacos的配置，关系到springboot、springcloud、spring cloud alibaba的版本都有关系。我的版本对应如下：

springboot	spring cloud	spring cloud alibaba	nacos
2.2.1.RELEASE	Hoxton.RELEASE	2.2.0.RELEASE	1.4.1