The Connection descriptor used by the client was……解决方法！

ORA-12505, TNS:listener does not currently know of SID given in connect descriptor
The Connection descriptor used by the client was:
localhost:1521:orcl

 

改了数据源然后就发生上面的错误，真是郁闷到了极点！

多次尝试无效后，我导入了一个oracle自带的包：classes12.jar

然后问题就奇迹般解决了，真搞不懂究竟是咋回事！！！！！