Type interface nynu.mapper.StudentMapper is not known to the MapperRegistry.

这个错误通常是由于MyBatis配置文件中未正确配置Mapper接口引起的。当MyBatis启动时，它会扫描配置文件中指定的包路径，寻找所有的Mapper接口，并将其注册到MapperRegistry中。如果找不到指定的Mapper接口，就会报错。

要解决这个问题，你可以按照以下步骤进行检查和修复：

1. 确保Mapper接口的包路径正确配置在MyBatis的配置文件中。在配置文件中，通常会有一个`<mappers>`标签，里面包含了所有Mapper接口的路径配置。检查这个配置是否正确，并且确保Mapper接口所在的包路径与配置一致。

2. 确保Mapper接口的命名规范正确。MyBatis默认使用Mapper接口的全限定名作为映射器的ID，所以请确保Mapper接口的命名规范符合要求。

3. 检查Mapper接口是否正确地被扫描到。可以通过查看MyBatis启动时的日志信息来确认是否成功扫描到了Mapper接口。如果没有扫描到，可能是包路径配置错误或者Mapper接口所在的包没有被正确扫描到。

4. 如果以上步骤都没有解决问题，可以尝试重新编译项目并清理缓存。有时候编译错误或者缓存问题也会导致这个错误。

希望以上解答对你有帮助！如果还有其他问题，请继续提问。

相关问题

Error creating bean with name 'address1' defined in file [C:\IDEA\ktlx\target\classes\edu\nynu\pojo\Address1.class]

: Instantiation of bean failed; nested exception is java.lang.NoClassDefFoundError: org/springframework/beans/factory/BeanCreationException

This error occurs when Spring is unable to create a bean due to an issue with the Address1 class. The nested exception indicates that there is a missing class definition for BeanCreationException, which is a class used by Spring to handle errors during bean creation.

To resolve this issue, check that all required dependencies are included in the project's classpath and that there are no issues with the Address1 class definition. Additionally, check that the configuration for the bean is correct and that any required properties are properly set.