ORA-12505 oracle11g

Error while performing database login with the oracle.jdbc.driver.Oracle driver:
listener refused the connection with the following error:
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

那位大神教教我啊
？！！！！！！！！

你用什么连接的数据库？是工具还是啥？
tnsnames.ora里是怎么配置的？

看报的错误应该是你的连接串没有配置正确。 确认一下你的oracle_sid是不是orcl,还是有是把localhost改成127.0.0.1试试。