mybatis连接mysql（jdbc）常见问题

问题1：java.io.IOException: Could not find resource com/xxx/xxxMapper.xml

IDEA是不会编译src的java目录的xml文件，所以在Mybatis的配置文件中找不到xml文件。不将xml放到src目录下面，将xxxMapper.xml放到Maven构建的resource目录下面。

问题2：MySQLException: Unknown system variable 'query_cache_size'

5.1.45 版本可以，6.0.2版本不行

问题3：Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.

根据提示：

url=jdbc:mysql://127.0.0.1:3306/framework?characterEncoding=utf8&useSSL=true