SQL Server默认端口号为：1433

URL:"jdbc:microsoft:SQL Server://localhost:1433;DatabaseName=dbname"  
DRIVERNAME:"com.microsoft.jdbc.SQL Server.SQL ServerDriver";  

MySQL 默认端口号为：3306

URL:jdbc:MySQL://localhost:3306/test? user=root&password=&useUnicode=true&characterEncoding=gbk 
DRIVERNAME:"com.MySQL.jdbc.Driver";  

Oracle 默认端口号为：1521

URL:"jdbc:Oracle:thin:@localhost:1521:orcl ";  
DRIVERNAME:"Oracle.jdbc.driver.OracleDriver