python && Java && jsp + servlet database connection error collection (sql server, mysql)

Written at the top: SQL Server and mysql are different things . . .

I am in complete java database connection when this both as a thing, results in the mysql jar package.

But his is sql server. .

Then try using python time it was under pymysql, and was once considered a blogger pymssql is a typo = =.

So it never connects. It reported the number of errors does not count them out:

java.sql.SQLNonTransientConnectionException: Cannot load connection class be...、

tomcat timeout,

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.

com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure

.... (and many can not find it)