05.443 ERROR o.a.c.c.C.[.[.[.[dispatcherServlet]:175 Servlet.service() for servlet [dispatcherServlet] in context with path [/system] threw exception [Request processing failed; nested exception is org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.exceptions.PersistenceException:

Error querying database. Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up.

The error may exist in file [D:\learning\Spring MOOC\course\system\target\classes\mapper\TestMapper.xml]

The error may involve com.course.system.mapper.TestMapper.list

The error occurred while executing a query

Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up.] with root cause