HTTP状态 500 - 内部服务器错误

问题描述：

org.springframework.web.util.NestedServletException: 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 java.sql.SQLException: Access denied for user 'root'@'localhost' (using password: YES)
### The error may exist in com/imooc/reader/mapper/CategoryMapper.java (best guess)
### The error may involve com.imooc.reader.mapper.CategoryMapper.selectList
### The error occurred while executing a query
### Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is java.sql.SQLException: Access denied for user 'root'@'localhost' (using password: YES)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1014)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898)
javax.servlet.http.HttpServlet.service(HttpServlet.java:626)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
javax.servlet.http.HttpServlet.service(HttpServlet.java:733)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)

尝试过的解决方式：

Access denied for user 'root'@'localhost' (using password: YES)

msql授权无密码访问，依旧链接不上