错误：

Exception in thread “main” org.apache.ibatis.exceptions.PersistenceException:Error querying database. Cause:com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server.
The error may exist in cn/action/dao/UserDao.xml
The error may involve cn.action.dao.UserDao.findList
The error occurred while executing a query
Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server.
at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:30)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:150)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:141)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:136)
at cn.action.test01.TestSelectList.main(TestSelectList.java:29)
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)

原因：

MySql8.0应用低版本jar包，产生错误

解决：

1.下载高版本jar包

下载后解压：

2.更改驱动名

以前：com.mysql.jdbc.Driver

更改后：com.mysql.cj.jdbc.Driver

3.删除原来的驱动包

项目上右键->Build Path->Configure Build Path->Libraries中带错误的jar包remove

4.由于版本时区不同，要在数据库后加上“?serverTimezone=UTC"