MyBatis-Spring-Boot
MyBatis-Spring-Boot copied to clipboard
abel533
sun.reflect.generics.reflectiveObjects.TypeVariableImpl cannot be cast to java.lang.Class
遇到了奇怪的报错：
Caused by: java.lang.RuntimeException: java.lang.RuntimeException: java.lang.ClassCastException: sun.reflect.generics.reflectiveObjects.TypeVariableImpl cannot be cast to java.lang.Class at tk.mybatis.mapper.mapperhelper.MapperHelper.setSqlSource(MapperHelper.java:247) at tk.mybatis.mapper.mapperhelper.MapperHelper.processConfiguration(MapperHelper.java:310) at tk.mybatis.spring.mapper.MapperFactoryBean.checkDaoConfig(MapperFactoryBean.java:54) at org.springframework.dao.support.DaoSupport.afterPropertiesSet(DaoSupport.java:44) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1637) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1574) ... 52 more Caused by: java.lang.RuntimeException: java.lang.ClassCastException: sun.reflect.generics.reflectiveObjects.TypeVariableImpl cannot be cast to java.lang.Class at tk.mybatis.mapper.mapperhelper.MapperTemplate.setSqlSource(MapperTemplate.java:246) at tk.mybatis.mapper.mapperhelper.MapperHelper.setSqlSource(MapperHelper.java:244) ... 57 more Caused by: java.lang.ClassCastException: sun.reflect.generics.reflectiveObjects.TypeVariableImpl cannot be cast to java.lang.Class at tk.mybatis.mapper.mapperhelper.MapperTemplate.getEntityClass(MapperTemplate.java:278) at tk.mybatis.mapper.provider.base.BaseUpdateProvider.updateByPrimaryKeySelective(BaseUpdateProvider.java:64) at sun.reflect.GeneratedMethodAccessor61.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:497) at tk.mybatis.mapper.mapperhelper.MapperTemplate.setSqlSource(MapperTemplate.java:234) ... 58 more
应该是你写错了。有可能属于下面的某种情况：
AMapper<A> extends Mapper<A>
或者
AMapper extends Mapper
正确的应该是
AMapper extends Mapper<A>
刚才把代码搜了一遍，写法和上面说的一致。
我这边的场景是这样的：
这种写法就不报错 package com.sns.schedule; @SpringBootApplication(scanBasePackages = {"com.sns"}) public class Application{
这样写就报上面的错（之所以这么折腾老代码，是觉得下面的写法优雅）： package com.sns; @SpringBootApplication public class Application{
老代码比较早，当时还没有通用mapper的autoconfig,
通用mapper的的MyMapper.java在“com.sns.data”下， 业务Mapper是使用“tk.mybatis.spring.mapper.MapperScannerConfigurer”来自动配置，
你看看有没有上面写的问题，具体代码如下：
这个有。代码写的比较乱，把能用或不能用的dependencies都放到Pom文件中了。 但是在代码中显式声明了tk.mybatis.spring.mapper.MapperScannerConfigurer，按照starter这种自动配置的逻辑，如果有MapperScannerConfigurer的实例了，就不会再重复初始化实例了 这样看的话，应该也没有什么影响吧
