oracle 11g ORA 12514错误，我的解决办法

前言:网上有很多解决办法，删listener.ora也好，还是什么也好，都解决不了我这个问题，依然报12514错误，以下是我逐个尝试后成功的监听字符串。。
listener.ora文件：
# listener.ora Network Configuration File: d:\app\john\product\11.1.0\db_1\network\admin\listener.ora
# Generated by Oracle configuration tools.
SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = cjtfs)   
      (ORACLE_HOME = d:\app\john\product\11.1.0\db_1)
      (PROGRAM = cjtfs)
    )
     (SID_DESC =
      (GLOBAL_DBNAME = cjtfs)
      (ORACLE_HOME = d:\app\john\product\11.1.0\db_1)
      (SID_NAME = cjtfs)
    )
  )
LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = john-PC)(PORT = 1521))
    )
  )
tnsnames.ora文件：
# tnsnames.ora Network Configuration File: d:\app\john\product\11.1.0\db_1\network\admin\tnsnames.ora
# Generated by Oracle configuration tools.
CJTFS =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = john-PC)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = cjtfs)   #要和listener.ora里面的cjtfs位置的名字保持一致
    )
  )
如果还解决不了，那就留言，我一般会常看blog的。。。。大家一起解决。。互相学习。