（报错记录）org.apache.ibatis.type.TypeException: Could not resolve type alias ‘xxx‘

Exception encountered during context initialization - cancelling refresh attempt: org.springframework.context.ApplicationContextException: Unable to start web server; nested exception is java.lang.RuntimeException: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name ‘securityConfigurer. FormLoginWebSecurityConfigurerAdapter’ defined in file [D:\Program_data\new_workspace\xzs-mysql\source\xzs\service\service_exam\target\classes\com\mindskip\xzs\configuration\spring\security\SecurityConfigurer$FormLoginWebSecurityConfigurerAdapter.class]: Unsatisfied dependency expressed through constructor parameter 2; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name ‘restAuthenticationProvider’ defined in file [D:\Program_data\new_workspace\xzs-mysql\source\xzs\service\service_exam\target\classes\com\mindskip\xzs\configuration\spring\security\RestAuthenticationProvider.class]: Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name ‘authenticationServiceImpl’ defined in file [D:\Program_data\new_workspace\xzs-mysql\source\xzs\service\service_exam\target\classes\com\mindskip\xzs\service\impl\AuthenticationServiceImpl.class]: Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name ‘userServiceImpl’ defined in file [D:\Program_data\new_workspace\xzs-mysql\source\xzs\service\service_exam\target\classes\com\mindskip\xzs\service\impl\UserServiceImpl.class]: Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name ‘userMapper’ defined in file [D:\Program_data\new_workspace\xzs-mysql\source\xzs\service\service_user\target\classes\com\mindskip\userservice\repository\UserMapper.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:\Program_data\new_workspace\xzs-mysql\source\xzs\service\service_user\target\classes\mapper\MessageMapper.xml]’; nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. The XML location is ‘file [D:\Program_data\new_workspace\xzs-mysql\source\xzs\service\service_user\target\classes\mapper\MessageMapper.xml]’. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias ‘com.mindskip.xzs.viewmodel.admin.message.MessagePageRequestVM’. Cause: java.lang.ClassNotFoundException: Cannot find class: com.mindskip.xzs.viewmodel.admin.message.MessagePageRequestVM

做微服务拆分的时候碰到的，关键在于Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias ‘com.mindskip.xzs.viewmodel.admin.message.MessagePageRequestVM’.
也就是说MyBatis在解析配置文件时遇到了一个类找不到的问题，导致无法构建映射关系。具体来说，MyBatis 找不到名为 com.mindskip.xzs.viewmodel.admin.message.MessagePageRequestVM 的类型别名。
然后在MessageMapper.xml查找一下，果然

直接ctrl+x的，里边包名没改，MessagePageRequestVM早就被我挪到com.mindskip.userservice包下面了