我还没有看到广泛讨论的一种可能性是，在主机上解析主机名本身可能存在问题。如果在/etc/hosts中没有$(hostname)条目，Oracle侦听器会感到困惑，不会出现。

这原来是我的问题，在/etc/hosts中添加主机名和ip地址解决了这个问题。

当我使用以下代码时，我的问题得到了解决:

Class.forName("oracle.jdbc.driver.OracleDriver");
Connection conn=DriverManager.getConnection("jdbc:oracle:thin:@IPAddress:1521/servicename","userName","Password");

I too faced the same issue. I had installed Oracle Express edition 10g in Windows XP OS using VMware and it was working fine. Since it was very awkward typing SQL queries in the SQL utility provided by 10g and since I was used to working with SQL developer, I installed 32 bit SQL developer in XP and tried connecting to my DB SID "XE". But the connection failed with error-ORA-12505 TNS listener doesn't currently know of SID given in connect descriptor. I was at sea as to how this problem occurred since it was working fine with the SQL utility and I had also created few Informatica mappings using the same. I did browse a lot on this stuff hither thither and applied the suggestions offered to me after pinging the status of "lsnrctl" on public forums but to no avail. However, this morning I tried creating a new connection again, and Voila, it worked with no issues. I am guessing after reading in few posts that sometimes listener listens before the DB connects or something(pardon me for my crude reference as I am a newbie here) but I suggest to just restart the machine and check again.

我通过纠正JDBC代码解决了这个问题。

正确的JDBC字符串应该是…

conection = DriverManager.getConnection
("jdbc:oracle:thin:@localhost:1521:xe","system","ishantyagi");

但是我使用的JDBC字符串是…

conection = DriverManager.getConnection
("jdbc:oracle:thin:@localhost:1521:orcl","system","ishantyagi");

因此，指定orcl而不是xe的错误显示了这个错误，因为SID名称是错误的。

我只是错误地创建了数据库链接。

对我来说，简单的解决方法是简单地将“SID”更改为SERVICE_NAME

CREATE DATABASE LINK my_db_link
CONNECT TO myUser IDENTIFIED BY myPassword
USING
'
(
    DESCRIPTION=
    (
        ADDRESS=
        (PROTOCOL=TCP)
        (HOST=host-name-heren)
        (PORT=1521)
    )
    (CONNECT_DATA=(SID=theNameOfTheDatabase))
)';

改变

SID=theNameOfTheDatabase

to

SERVICE_NAME=theNameOfTheDatabase 

解决了我的问题。

我在SQL Workbench中也遇到过类似的问题。

URL:

jdbc: oracle:薄:@111.111.111.111:1111:xe

是行不通的。

URL:

jdbc: oracle:薄:@111.111.111.111:1111:asdb

的工作原理。

这对我的具体情况有帮助。恐怕还有许多其他的原因和不同的解决办法。