在学习Spring框架中的注解时，第一次测试就出现了这个问题，百思不得其解
最后发现是JDK和Spring的版本不匹配，我的Spring框架版本为5.2.6 仅仅支持到JDK15 而我的是JDK16，由此出现了问题
- Spring framework 5.3.x: JDK 8-17 (expected)
- Spring framework 5.2.x: JDK 8-15 (expected)
- Spring framework 5.1.x: JDK 8-12
- Spring framework 5.0.x: JDK 8-10
- Spring framework 4.3.x: JDK 6-8
本来准备再下载一个JDK8，突然发现在File-Setting-Build, Execution... - Java Compiler中能够调整Project bytecode version将这里由16修改为15 问题得以解决
错误：org.springframework.beans.factory.BeanDefinitionStoreException: Failed to read candidate component class: file [D:java学习spring5_demo3outproductionspring5_demo3comspring5serviceUserService.class]; nested exception is org.springframework.core.NestedIOException: ASM ClassReader failed to parse class file - probably due to a new Java class file version that isn’t supported yet: file [D:java学习spring5_demo3outproductionspring5_demo3comspring5serviceUserService.class]; nested exception is java.lang.IllegalArgumentException: Unsupported class file major version 60
