将“spring cloud starter aws”启动程序包添加到spring Boot应用程序时出现FileNotFoundException

Question

我有一个成熟的Spring Boot服务器应用程序。我正在通过一篇文章来配置Spring以将指标发送到AWS Cloudwatch。

当我包含启动程序包Spring-Cloud-starter-aws时，我遇到了运行时异常。有人能告诉我为什么我得到了这个例外，我能做些什么来解决这个问题吗？

以下是两种摘要形式的例外：

Caused by: java.io.FileNotFoundException: class path resource [org/springframework/cloud/aws/jdbc/config/annotation/AmazonRdsInstanceConfiguration$AbstractRegistrar.class] cannot be opened because it does not exist

长格式：

org.springframework.beans.factory.BeanDefinitionStoreException: Failed to process import candidates for configuration class [org.springframework.cloud.aws.autoconfigure.jdbc.AmazonRdsDatabaseAutoConfiguration]; nested exception is java.io.FileNotFoundException: class path resource [org/springframework/cloud/aws/jdbc/config/annotation/AmazonRdsInstanceConfiguration$AbstractRegistrar.class] cannot be opened because it does not exist
at org.springframework.context.annotation.ConfigurationClassParser.processImports(ConfigurationClassParser.java:599)
at org.springframework.context.annotation.ConfigurationClassParser.doProcessConfigurationClass(ConfigurationClassParser.java:302)
at org.springframework.context.annotation.ConfigurationClassParser.processConfigurationClass(ConfigurationClassParser.java:242)
at org.springframework.context.annotation.ConfigurationClassParser.processImports(ConfigurationClassParser.java:589)
at org.springframework.context.annotation.ConfigurationClassParser.access$900(ConfigurationClassParser.java:108)
at org.springframework.context.annotation.ConfigurationClassParser$DeferredImportSelectorGroupingHandler.lambda$processGroupImports$1(ConfigurationClassParser.java:808)
at java.util.ArrayList.forEach(ArrayList.java:1257)
at org.springframework.context.annotation.ConfigurationClassParser$DeferredImportSelectorGroupingHandler.processGroupImports(ConfigurationClassParser.java:804)
at org.springframework.context.annotation.ConfigurationClassParser$DeferredImportSelectorHandler.process(ConfigurationClassParser.java:774)
at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:185)
at org.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigBeanDefinitions(ConfigurationClassPostProcessor.java:315)
at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(ConfigurationClassPostProcessor.java:232)
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:691)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:528)
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:142)
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 com.inlet.ifserver.IfserverApplication.main(IfserverApplication.java:19)

Caused by: java.io.FileNotFoundException: class path resource [org/springframework/cloud/aws/jdbc/config/annotation/AmazonRdsInstanceConfiguration$AbstractRegistrar.class] cannot be opened because it does not exist
at org.springframework.core.io.ClassPathResource.getInputStream(ClassPathResource.java:180)
at org.springframework.core.type.classreading.SimpleMetadataReader.<init>(SimpleMetadataReader.java:51)
at org.springframework.core.type.classreading.SimpleMetadataReaderFactory.getMetadataReader(SimpleMetadataReaderFactory.java:103)
at org.springframework.boot.type.classreading.ConcurrentReferenceCachingMetadataReaderFactory.createMetadataReader(ConcurrentReferenceCachingMetadataReaderFactory.java:88)
at org.springframework.boot.type.classreading.ConcurrentReferenceCachingMetadataReaderFactory.getMetadataReader(ConcurrentReferenceCachingMetadataReaderFactory.java:75)
at org.springframework.core.type.classreading.SimpleMetadataReaderFactory.getMetadataReader(SimpleMetadataReaderFactory.java:81)
at org.springframework.context.annotation.ConfigurationClassParser.asSourceClass(ConfigurationClassParser.java:685)
at org.springframework.context.annotation.ConfigurationClassParser$SourceClass.getSuperClass(ConfigurationClassParser.java:998)
at org.springframework.context.annotation.ConfigurationClassParser.doProcessConfigurationClass(ConfigurationClassParser.java:332)
at org.springframework.context.annotation.ConfigurationClassParser.processConfigurationClass(ConfigurationClassParser.java:242)
at org.springframework.context.annotation.ConfigurationClassParser.processImports(ConfigurationClassParser.java:589)
... 20 more

我使用IntelliJ，查看了“External Libraries”列表，发现了这个异常所抱怨的类。IntelliJ反编译代码，我可以看到它是一个公共类，包含一个公共抽象类。看来斯普林应该找到这门课了。

任何对此的帮助都将不胜感激。

Answer 1

除了第一篇文章之外，我还查阅了多个文档来源。似乎没有人提到你不能独自去“Spring云启动程序aws”。我不确定我包含的其他模块对这一点有多大影响，但我在maven central repository中找到了这个模块，并将其添加到我的项目中解决了上述问题：

spring-cloud-starter-aws-jdbc

也许我应该早点想到这一点，但Spring Boot的整个想法是，我认为，通过约定进行配置意味着你总是能从启动器本身获得一些东西。我没有使用JDBC，那么为什么我需要包括这个呢？如果不提供，需要它的功能就不应该可用。这是第一次使用Spring Boot，包括一个启动器，我需要包括另一个模块，以避免运行时异常。哦，好吧。

更新：我在Spring Cloud文档中找到了更多文档，但仍然很粗略。医生说

必须添加额外的依赖项，以支持消息传递和JDBC等特定功能。Spring Cloud AWS将只配置Spring Boot应用程序的类路径中可用的类

这是误导。必须添加这些额外的依赖项。。。时期不管你是否想“启用特定功能”，我不想。

顺便说一句，我并没有完全摆脱困境，一旦我添加了这个额外的依赖。我还有另外两个例外，涉及要修复的配置添加。我必须大声定义属性。aws。区域静态=[my region]和云。aws。堆栈自动=错误。也不是很像Spring的靴子。如果不在EC2实例上，就必须指定AWS区域是有意义的，但如果我不使用它，就必须考虑CloudFormation。Spring Cloud文档至少在以下几点上更加清晰：https://cloud.spring.io/spring-cloud-aws/1.2.x/#_configuring_region和https://cloud.spring.io/spring-cloud-aws/1.2.x/#_cloudformation_configuration_in_spring_boot