Problem description

Today, we are integrating mybatis with springboot, and an error is reported at runtime:

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userController': Unsatisfied dependency expressed through field 'userService'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userServiceImpl': Unsatisfied dependency expressed through field 'baseMapper'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userMapper' defined in file [E:\IDEA Project\demo\target\classes\com\example\demo\mapper\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 [com/baomidou/mybatisplus/autoconfigure/MybatisPlusAutoConfiguration.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 [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'; nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. The XML location is 'file [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'com.libv.entity.Version'.  Cause: java.lang.ClassNotFoundException: Cannot find class: com.libv.entity.Version
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.resolveFieldValue(AutowiredAnnotationBeanPostProcessor.java:659) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:639) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:119) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:399) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1431) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:619) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:953) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918) ~[spring-context-5.3.16.jar:5.3.16]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583) ~[spring-context-5.3.16.jar:5.3.16]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.6.4.jar:2.6.4]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:740) [spring-boot-2.6.4.jar:2.6.4]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:415) [spring-boot-2.6.4.jar:2.6.4]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:303) [spring-boot-2.6.4.jar:2.6.4]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1312) [spring-boot-2.6.4.jar:2.6.4]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1301) [spring-boot-2.6.4.jar:2.6.4]
	at com.example.demo.DemoApplication.main(DemoApplication.java:18) [classes/:na]
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userServiceImpl': Unsatisfied dependency expressed through field 'baseMapper'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userMapper' defined in file [E:\IDEA Project\demo\target\classes\com\example\demo\mapper\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 [com/baomidou/mybatisplus/autoconfigure/MybatisPlusAutoConfiguration.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 [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'; nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. The XML location is 'file [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'com.libv.entity.Version'.  Cause: java.lang.ClassNotFoundException: Cannot find class: com.libv.entity.Version
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.resolveFieldValue(AutowiredAnnotationBeanPostProcessor.java:659) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:639) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:119) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:399) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1431) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:619) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1389) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1309) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.resolveFieldValue(AutowiredAnnotationBeanPostProcessor.java:656) ~[spring-beans-5.3.16.jar:5.3.16]
	... 20 common frames omitted
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userMapper' defined in file [E:\IDEA Project\demo\target\classes\com\example\demo\mapper\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 [com/baomidou/mybatisplus/autoconfigure/MybatisPlusAutoConfiguration.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 [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'; nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. The XML location is 'file [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'com.libv.entity.Version'.  Cause: java.lang.ClassNotFoundException: Cannot find class: com.libv.entity.Version
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireByType(AbstractAutowireCapableBeanFactory.java:1534) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1417) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:619) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1389) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1309) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.resolveFieldValue(AutowiredAnnotationBeanPostProcessor.java:656) ~[spring-beans-5.3.16.jar:5.3.16]
	... 34 common frames omitted
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sqlSessionFactory' defined in class path resource [com/baomidou/mybatisplus/autoconfigure/MybatisPlusAutoConfiguration.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 [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'; nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. The XML location is 'file [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'com.libv.entity.Version'.  Cause: java.lang.ClassNotFoundException: Cannot find class: com.libv.entity.Version
	at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:658) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:638) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1352) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1195) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:582) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1389) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1309) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireByType(AbstractAutowireCapableBeanFactory.java:1519) ~[spring-beans-5.3.16.jar:5.3.16]
	... 45 common frames omitted
Caused by: 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 [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'; nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. The XML location is 'file [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'com.libv.entity.Version'.  Cause: java.lang.ClassNotFoundException: Cannot find class: com.libv.entity.Version
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185) ~[spring-beans-5.3.16.jar:5.3.16]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:653) ~[spring-beans-5.3.16.jar:5.3.16]
	... 58 common frames omitted
Caused by: org.springframework.core.NestedIOException: Failed to parse mapping resource: 'file [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'; nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. The XML location is 'file [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'com.libv.entity.Version'.  Cause: java.lang.ClassNotFoundException: Cannot find class: com.libv.entity.Version
	at com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean.buildSqlSessionFactory(MybatisSqlSessionFactoryBean.java:595) ~[mybatis-plus-extension-3.4.0.jar:3.4.0]
	at com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean.afterPropertiesSet(MybatisSqlSessionFactoryBean.java:431) ~[mybatis-plus-extension-3.4.0.jar:3.4.0]
	at com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean.getObject(MybatisSqlSessionFactoryBean.java:628) ~[mybatis-plus-extension-3.4.0.jar:3.4.0]
	at com.baomidou.mybatisplus.autoconfigure.MybatisPlusAutoConfiguration.sqlSessionFactory(MybatisPlusAutoConfiguration.java:214) ~[mybatis-plus-boot-starter-3.3.1.jar:3.3.1]
	at com.baomidou.mybatisplus.autoconfigure.MybatisPlusAutoConfiguration$$EnhancerBySpringCGLIB$$1a37b21a.CGLIB$sqlSessionFactory$2(<generated>) ~[mybatis-plus-boot-starter-3.3.1.jar:3.3.1]
	at com.baomidou.mybatisplus.autoconfigure.MybatisPlusAutoConfiguration$$EnhancerBySpringCGLIB$$1a37b21a$$FastClassBySpringCGLIB$$a0eb9858.invoke(<generated>) ~[mybatis-plus-boot-starter-3.3.1.jar:3.3.1]
	at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:244) ~[spring-core-5.3.16.jar:5.3.16]
	at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:331) ~[spring-context-5.3.16.jar:5.3.16]
	at com.baomidou.mybatisplus.autoconfigure.MybatisPlusAutoConfiguration$$EnhancerBySpringCGLIB$$1a37b21a.sqlSessionFactory(<generated>) ~[mybatis-plus-boot-starter-3.3.1.jar:3.3.1]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_322]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_322]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_322]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_322]
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.3.16.jar:5.3.16]
	... 59 common frames omitted
Caused by: org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. The XML location is 'file [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'com.libv.entity.Version'.  Cause: java.lang.ClassNotFoundException: Cannot find class: com.libv.entity.Version
	at org.apache.ibatis.builder.xml.XMLMapperBuilder.configurationElement(XMLMapperBuilder.java:123) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.builder.xml.XMLMapperBuilder.parse(XMLMapperBuilder.java:95) ~[mybatis-3.5.5.jar:3.5.5]
	at com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean.buildSqlSessionFactory(MybatisSqlSessionFactoryBean.java:593) ~[mybatis-plus-extension-3.4.0.jar:3.4.0]
	... 72 common frames omitted
Caused by: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'com.libv.entity.Version'.  Cause: java.lang.ClassNotFoundException: Cannot find class: com.libv.entity.Version
	at org.apache.ibatis.builder.BaseBuilder.resolveClass(BaseBuilder.java:118) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.builder.xml.XMLStatementBuilder.parseStatementNode(XMLStatementBuilder.java:76) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.builder.xml.XMLMapperBuilder.buildStatementFromContext(XMLMapperBuilder.java:138) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.builder.xml.XMLMapperBuilder.buildStatementFromContext(XMLMapperBuilder.java:131) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.builder.xml.XMLMapperBuilder.configurationElement(XMLMapperBuilder.java:121) ~[mybatis-3.5.5.jar:3.5.5]
	... 74 common frames omitted
Caused by: org.apache.ibatis.type.TypeException: Could not resolve type alias 'com.libv.entity.Version'.  Cause: java.lang.ClassNotFoundException: Cannot find class: com.libv.entity.Version
	at org.apache.ibatis.type.TypeAliasRegistry.resolveAlias(TypeAliasRegistry.java:120) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.builder.BaseBuilder.resolveAlias(BaseBuilder.java:149) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.builder.BaseBuilder.resolveClass(BaseBuilder.java:116) ~[mybatis-3.5.5.jar:3.5.5]
	... 78 common frames omitted
Caused by: java.lang.ClassNotFoundException: Cannot find class: com.libv.entity.Version
	at org.apache.ibatis.io.ClassLoaderWrapper.classForName(ClassLoaderWrapper.java:200) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.io.ClassLoaderWrapper.classForName(ClassLoaderWrapper.java:89) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.io.Resources.classForName(Resources.java:261) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.type.TypeAliasRegistry.resolveAlias(TypeAliasRegistry.java:116) ~[mybatis-3.5.5.jar:3.5.5]
	... 80 common frames omitted

Cause analysis:

When I first saw this error report, I guessed that the bean was not successfully created. I also searched various answers on the Internet. Some said that @ service might not be added to the service layer. I looked at it for no reason, so I began to read the error information

Look directly at the error reported in the first line, because the first line is likely to be the main reason for the error:

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userController': Unsatisfied dependency expressed through field 'userService'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userServiceImpl': Unsatisfied dependency expressed through field 'baseMapper'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userMapper' defined in file [E:\IDEA Project\demo\target\classes\com\example\demo\mapper\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 [com/baomidou/mybatisplus/autoconfigure/MybatisPlusAutoConfiguration.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 [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'; nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. The XML location is 'file [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'com.libv.entity.Version'.  Cause: java.lang.ClassNotFoundException: Cannot find class: com.libv.entity.Version

I’ll take this long paragraph wrong and look at it in pieces
at first, I thought it was the problem of userController, then carefully check whether it was not, and then look back:

nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userServiceImpl'

I went to see userServiceImpl again and didn’t find any problems, so I was wondering if I understood the error in this paragraph, so I searched the meaning of nest. It turned out that there was nesting besides nesting! That is to say, the error reporting in this paragraph is actually an exception nested with another exception ! In other words, it is the innermost error that causes the error of each layer above, thus throwing an exception! So I went straight to the back part:

nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. The XML location is 'file [E:\IDEA Project\demo\target\classes\mapper\VersionMapper.xml]'. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'com.libv.entity.Version'.  Cause: java.lang.ClassNotFoundException: Cannot find class: com.libv.entity.Version

Found to be VersionMapper.xml has a problem because of Error resolving class, That is to say, there is a problem with one class. Look at the last: Cannot find class: com.libv.entity.Version.
I went to see XML again:

<mapper namespace="com.libv.mapper.VersionMapper">
    <insert id="release" parameterType="com.libv.entity.Version">
        insert into version(id,version,download_url,release_time)
        values (#{id},#{version},#{downloadUrl},NOW())
    </insert>
</mapper>

Now I understand, because I don’t have com.libv.entity this bag! That is, the wrong path of my Version class leads to errors in XML, resulting in layer-by-layer exceptions.

Solution:

Change the directory path of the corresponding class of parameterType in XML

<mapper namespace="com.example.demo.mapper.VersionMapper">
    <insert id="release" parameterType="com.example.demo.Entity.Version">
        insert into version(id,version,download_url,release_time)
        values (#{id},#{version},#{downloadUrl},NOW())
    </insert>
</mapper>

Run again, success!