阿里云对象存储OSS奇葩异常的隐秘原因

首先，可以正常使用的各组件版本

目前测试正常的各组件详细版本如下：
Spring Cloud：Hoxton.SR5；
Spring Boot：2.2.12.RELEASE；
spring-cloud-alibaba-dependencies：2.2.1.RELEASE；
aliyun-oss-spring-boot-starter：1.1.0；
MyBatis Plus：3.4.1；
JDK：11.0.9；
Nacos：1.4.0。

其次，相关配置文件详细内容

（参考文档：《导入OSS依赖不兼容问题》、《spring-cloud-starter-alicloud-oss 依赖导入失败问题》）

1、application.yml文件：

#  阿里云OSS配置暂时先放在此处(后续会放在Nacos配置中心)：
alibaba:
  cloud:
    access-key: L****t
    secret-key: x****Z
    oss:
      endpoint: oss-cn-beijing.aliyuncs.com
      bucket: xxx

2、pom.xml文件：

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0modelVersion>
    <parent>
        <groupId>org.springframework.bootgroupId>
        <artifactId>spring-boot-starter-parentartifactId>
        <version>2.2.12.RELEASEversion>
        <relativePath/>
    parent>
    <groupId>com.xxx.xxxxgroupId>
    <artifactId>xxx-third-partyartifactId>
    <version>0.0.1-SNAPSHOTversion>
    <name>xxx-***name>
    <description>***服务description>

    <properties>
        <java.version>11java.version>
        <spring-cloud.version>Hoxton.SR5spring-cloud.version>
    properties>

    <dependencies>
        <dependency>
            <groupId>com.***.****groupId>
            <artifactId>****-commonartifactId>
            <version>0.0.1-SNAPSHOTversion>
            <exclusions>
                <exclusion>
                    <groupId>com.baomidougroupId>
                    <artifactId>mybatis-plus-boot-starterartifactId>
                exclusion>
            exclusions>
        dependency>
        
        <dependency>
            <groupId>com.alibaba.cloudgroupId>
            <artifactId>aliyun-oss-spring-boot-starterartifactId>
            
            <version>1.0.0version>
            <exclusions>
                
                <exclusion>
                    <groupId>com.aliyungroupId>
                    <artifactId>aliyun-java-sdk-ossartifactId>
                exclusion>
                
                <exclusion>
                    <groupId>com.aliyun.ossgroupId>
                    <artifactId>aliyun-sdk-ossartifactId>
                exclusion>
            exclusions>
        dependency>
        
        <dependency>
            <groupId>com.aliyungroupId>
            <artifactId>aliyun-java-sdk-coreartifactId>
            <version>4.5.7version>
        dependency>

        <dependency>
            <groupId>com.aliyun.ossgroupId>
            <artifactId>aliyun-sdk-ossartifactId>
            <version>3.10.2version>
        dependency>
        <dependency>
            <groupId>javax.xml.bindgroupId>
            <artifactId>jaxb-apiartifactId>
            <version>2.3.1version>
        dependency>
        <dependency>
            <groupId>javax.activationgroupId>
            <artifactId>activationartifactId>
            <version>1.1.1version>
        dependency>
        
        <dependency>
            <groupId>org.glassfish.jaxbgroupId>
            <artifactId>jaxb-runtimeartifactId>
            <version>2.3.3version>
        dependency>

        <dependency>
            <groupId>org.springframework.cloudgroupId>
            <artifactId>spring-cloud-config-serverartifactId>
            <version>2.2.6.RELEASEversion>
        dependency>

        <dependency>
            <groupId>org.springframework.cloudgroupId>
            <artifactId>spring-cloud-starter-openfeignartifactId>
        dependency>

        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-testartifactId>
            <scope>testscope>
        dependency>
		
        
    dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloudgroupId>
                <artifactId>spring-cloud-dependenciesartifactId>
                <version>${spring-cloud.version}version>
                <type>pomtype>
                <scope>importscope>
            dependency>
            <dependency>
                <groupId>com.alibaba.cloudgroupId>
                <artifactId>spring-cloud-alibaba-dependenciesartifactId>
                <version>2.2.1.RELEASEversion>
                <type>pomtype>
                <scope>importscope>
            dependency>
        dependencies>
    dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.bootgroupId>
                <artifactId>spring-boot-maven-pluginartifactId>
            plugin>
        plugins>
    build>

    <repositories>
        <repository>
            <id>spring-milestonesid>
            <name>Spring Milestonesname>
            <url>https://repo.spring.io/milestoneurl>
        repository>
    repositories>
project>

第三、奇葩异常及其隐秘原因

问题的“隐秘原因”在上面的pom.xml中已经注释说明，就是添加了下面的依赖：

<dependency>
    <groupId>com.aliyun.ossgroupId>
    <artifactId>aliyun-sdk-ossartifactId>
    <scope>testscope>
dependency>

该依赖应该是使用Maven构建项目时自动添加。
添加该依赖后，启动当前服务的应用程序，会出现一系列莫名其妙的异常。经过多次尝试后，将部分异常收集如下（可能有部分重复或者缺失的）：

java.lang.NoClassDefFoundError: org/junit/jupiter/api/extension/TestInstancePreDestroyCallback
Caused by: java.lang.ClassNotFoundException: org.junit.jupiter.api.extension.TestInstancePreDestroyCallback

java.lang.IllegalStateException: Error processing condition on com.alibaba.alicloud.context.oss.OssContextAutoConfiguration.ossClient

org.springframework.context.annotation.ConditionEvaluator.shouldSkip(ConditionEvaluator.java:108) ~[spring-context-5.2.12.RELEASE.jar:5.2.12.RELEASE]

Caused by: java.lang.IllegalStateException: @ConditionalOnMissingBean did not specify a bean using type, name or annotation and the attempt to deduce the bean's type failed at org.springframework.boot.autoconfigure.condition.OnBeanCondition$Spec.validate

java.lang.NoClassDefFoundError: com/aliyun/oss/OSS at com.alibaba.alicloud.oss.OssApplicationListener.onApplicationEvent(OssApplicationListener.java:41) ~[spring-cloud-alicloud-oss-2.2.1.RELEASE.jar:2.2.1.RELEASE] 
Caused by: java.lang.ClassNotFoundException: com.aliyun.oss.OSS
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:581) ~[na:na]
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178) ~[na:na]
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521) ~[na:na]
... 16 common frames omitted

Caused by: java.lang.IllegalStateException: @ConditionalOnMissingBean did not specify a bean using type, name or annotation and the attempt to deduce the bean's type failed at org.springframework.boot.autoconfigure.condition.OnBeanCondition$Spec.validate(OnBeanCondition.java:487) ~[spring-boot-autoconfigure-2.2.12.RELEASE.jar:2.2.12.RELEASE]

Caused by: org.springframework.boot.autoconfigure.condition.OnBeanCondition$BeanTypeDeductionException: Failed to deduce bean type for com.alibaba.cloud.spring.boot.oss.autoconfigure.OssContextAutoConfiguration.ossClient at org.springframework.boot.autoconfigure.condition.OnBeanCondition$Spec.deducedBeanTypeForBeanMethod(OnBeanCondition.java:517) ~[spring-boot-autoconfigure-2.2.12.RELEASE.jar:2.2.12.RELEASE]

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'ossClient' defined in class path resource [com/alibaba/cloud/spring/boot/oss/autoconfigure/OssContextAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.aliyun.oss.OSS]: Factory method 'ossClient' threw exception; nested exception is java.lang.IllegalArgumentException: Oss endpoint can't be empty.

Caused by: java.lang.IllegalStateException: @ConditionalOnMissingBean did not specify a bean using type, name or annotation and the attempt to deduce the bean's type failed
	at org.springframework.boot.autoconfigure.condition.OnBeanCondition$Spec.validate(OnBeanCondition.java:487) ~[spring-boot-autoconfigure-2.2.12.RELEASE.jar:2.2.12.RELEASE]
	at org.springframework.boot.autoconfigure.condition.OnBeanCondition$Spec.<init>(OnBeanCondition.java:436) ~[spring-boot-autoconfigure-2.2.12.RELEASE.jar:2.2.12.RELEASE]
java.lang.NoClassDefFoundError: com/aliyun/oss/OSS at com.alibaba.cloud.spring.boot.oss.context.OssApplicationListener.onApplicationEvent(OssApplicationListener.java:40) ~[aliyun-oss-spring-boot-starter-1.0.0.jar:1.0.0] at 
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'com.***.****.thirdparty.****ThirdPartyApplicationTests': Unsatisfied dependency expressed through field 'ossClient'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.aliyun.oss.OSS' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {
     @org.springframework.beans.factory.annotation.Autowired(required=true)}

直到将scope为test的依赖aliyun-sdk-oss注释或者删除，上述系列异常才消失无踪。