我已经在Linux（centOS）上安装了Oracle 11g Express Edition。即使服务运行正常，我也会收到“ ORA-12541：TNS：没有监听器”错误。
lsnrctl status
LSNRCTL for Linux: Version 11.2.0.2.0 - Production on 23-OCT-2018 16:22:49
Copyright (c) 1991, 2011, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC_FOR_XE)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 11.2.0.2.0 - Production
Start Date 23-OCT-2018 16:07:26
Uptime 0 days 0 hr. 15 min. 22 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Default Service XE
Listener Parameter File /u01/app/oracle/product/11.2.0/xe/network/admin/listener.ora
Listener Log File /u01/app/oracle/diag/tnslsnr/ruchanjoshi/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC_FOR_XE)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=xxx.xx.xxx.xxx)(PORT=1521)))
Services Summary...
Service "PLSExtProc" has 1 instance(s).
Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
Service "XE" has 1 instance(s).
Instance "XE", status READY, has 1 handler(s) for this service...
Service "XEXDB" has 1 instance(s).
Instance "XE", status READY, has 1 handler(s) for this service...
The command completed successfully
请帮助我连接服务器本身以及远程桌面上的数据库。