报错分析nest--嵌套

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'deptMapper' defined in file [D:\B-project\springboot-mybatis\target\classes\com\example\springmybatis\mapper\deptMapper.class]: Unsatisfied dependency expressed through bean property 'sqlSessionFactory';

 nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sqlSessionFactory' defined in class path resource [org/mybatis/spring/boot/autoconfigure/MybatisAutoConfiguration.class]: Bean instantiation via factory method failed; 

nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.apache.ibatis.session.SqlSessionFactory]: Factory method 'sqlSessionFactory' threw exception; 

nested exception is org.springframework.core.NestedIOException: Failed to parse mapping resource: 'file [D:\B-project\springboot-mybatis\target\classes\mapper\enumMapper.xml]';

 
nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. The XML location is 'file [D:\B-project\springboot-mybatis\target\classes\mapper\enumMapper.xml]'. 

Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'com.example.springmybatis.domain.enum'.  

Cause: java.lang.ClassNotFoundException: Cannot find class: com.example.springmybatis.domain.enum
	

兄弟，看见没有， 在IDEA里面这是一行，我拆分了一下，看一下每一行的第一个单词，nest。

这个单词什么意思，是嵌套的意思，这个bug意思UnsatisfiedDependencyException包裹了/嵌套了别的异常，别的异常包裹了别的异常。

这样一层层包裹下来，最后一行的cause才是根本原因。