我的电脑WINXP系统，oracle版本 10.2.0.1，java(jdk)版本1.50；出现错误如下：

Fatal NI connect error 12505, connecting to:

(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=localhost)(Port=1521))(CONNECT_DATA=(SID=orcl)(CID=(PROGRAM=D:\oracle\10.2.0\db_1\perl\5.8.3\bin\MSWin32-x86-multi-thread\perl.exe)(HOST=alevyxuw)(USER=SYSTEM))))

VERSION INFORMATION:

TNS for 32-bit Windows: Version 10.2.0.1.0 - Production

Windows NT TCP/IP NT Protocol Adapter for 32-bit Windows: Version 10.2.0.1.0 - Production

Time: 10-5月 -2007 01:11:46

Tracing not turned on.

Tns error struct:

ns main err code: 12564

TNS-12564: TNS: 拒绝连接

ns secondary err code: 0

nt main err code: 0

nt secondary err code: 0

nt OS err code: 0

检查listener.ora，sqlnet.ora，tnsnames.ora未发现异常。

最后一次是在Enterprise Manager Console，例程配置里面修改了‘内存’，调整了sga及pga，重启oracle后就无法监听，重新配置listener无效。sqlplus user/psw@sid 无法访问

C:\Documents and Settings\HP>sqlplus system/*****@orcl

SQL*Plus: Release 10.2.0.1.0 - Production on 星期四 5月 10 11:48:08 2007

Copyright (c) 1982, 2005, Oracle.  All rights reserved.

ERROR:

ORA-12514: TNS: 监听程序当前无法识别连接描述符中请求的服务

那位大侠可以指导一二，救人于水火之中！！！

附录：

1.listener.ora

# listener.ora Network Configuration File: D:\oracle\10.2.0\db_1\network\admin\listener.ora

# Generated by Oracle configuration tools.

SID_LIST_LISTENER =

(SID_LIST =

(SID_DESC =

(SID_NAME = PLSExtProc)

(ORACLE_HOME = D:\oracle\10.2.0\db_1)

(PROGRAM = extproc)

)

)

LISTENER =

(DESCRIPTION_LIST =

(DESCRIPTION =

(ADDRESS = (PROTOCOL = TCP)(HOST = 127.0.0.1)(PORT = 1521))

)

)

2.sqlnet.ora

# sqlnet.ora Network Configuration File: D:\oracle\10.2.0\db_1\network\admin\sqlnet.ora

# Generated by Oracle configuration tools.

# This file is actually generated by netca. But if customers choose to

# install "Software Only", this file wont exist and without the native

# authentication, they will not be able to connect to the database on NT.

SQLNET.AUTHENTICATION_SERVICES= (NTS)

NAMES.DIRECTORY_PATH= (TNSNAMES, EZCONNECT)

3.tnsnames.ora

# tnsnames.ora Network Configuration File: D:\oracle\10.2.0\db_1\network\admin\tnsnames.ora

# Generated by Oracle configuration tools.

orcl =

(DESCRIPTION =

(ADDRESS_LIST =

(ADDRESS = (PROTOCOL = TCP)(HOST = 127.0.0.1)(PORT = 1521))

)

(CONNECT_DATA =

(SERVICE_NAME = orcl)

)

)

EXTPROC_CONNECTION_DATA =

(DESCRIPTION =

(ADDRESS_LIST =

(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1))

)

(CONNECT_DATA =

(SID = PLSExtProc)

(PRESENTATION = RO)

)

)