Oracle ORA-12541,ORA-12514错误

1.昨天发布tomcat 成功，但登录后报错，无法打开hibernate session，检查后发现数据库无法连接

2.用PL/SQL登录数据库，报 ora-12541，TNS 无监听程序，百度发现需要配置监听，不得其解，因为我也没动过数据库，就尝试按照方法配置一遍

可以参考 http://www.cnblogs.com/Venom/p/3953025.html

然后不停重启

3.还是不行，又查到说在安装目录下更改文件配置，私以为两者应该效果一样。还是找到目录下文件打开瞅瞅

我的目录是：E:\app\albertfg\product\11.2.0\dbhome_1\NETWORK\ADMIN

在该目录下有3个文件：listener.ora；sqlnet.ora；tnsnames.ora；

4.第一个文件：

# listener.ora Network Configuration File: E:\app\username\product\11.2.\dbhome_1\network\admin\listener.ora
# Generated by Oracle configuration tools.

SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
    (GLOBAL_DBNAME = ORCL)
    (ORACLE_HOME = E:\app\username\product\11.2.\dbhome_1)
    (SID_NAME = ORCL)
    )
    (SID_DESC =

       (SID_NAME = CLRExtProc)
      (ORACLE_HOME = E:\app\albertfg\product\11.2.\dbhome_1)
      (PROGRAM = extproc)
      (ENVS = "EXTPROC_DLLS=ONLY:E:\app\username\product\11.2.0\dbhome_1\bin\oraclr11.dll")
    )
  )

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.101)(PORT = ))
    )
  )

ADR_BASE_LISTENER = E:\app\username

5：第三个文件：

# tnsnames.ora Network Configuration File: E:\app\username\product\11.2.\dbhome_1\network\admin\tnsnames.ora
# Generated by Oracle configuration tools.

ORACLR_CONNECTION_DATA =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
    )
    (CONNECT_DATA =
      (SID = CLRExtProc)
      (PRESENTATION = RO)
    )
  )

LISTENER_ORCL =
  (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = ))

ORCL =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.101)(PORT = ))
    )
    (CONNECT_DATA =
      (SERVICE_NAME = ORCL)
    )
  )

6.这样改完仍没用，报ora-12514

后来又百度发现重启oracle服务器，无奈，重启了一下电脑，恢复正常了。

7.小结：后来回想，主要是局域网内IP地址动态分配的，虽然我给了服务器固定ip，但昨天由于回来迟了，室友先开了机，恰巧又分配了服务器的ip地址

导致我的配置失效。记得以前也出现过一次，可惜没长记性，所以还是写点简单的记录吧。