title: ORA-12514: TNS:listener does not currently know of service requested in connect descriptor
body: <p>I have problem, when trying to connect to Oracle Database XE via listener:</p>
  
  <pre><code> sqlplus system/my_password@XE
  </code></pre>
  
  <p>I get the following error:</p>
  
  <pre><code>ORA-12514: TNS:listener does not currently know of service requested in connect
  descriptor
  </code></pre>
  
  <p>I use Ubuntu 12.10 and Oracle Express Edition 11g. </p>
  
  <p>My main goal to connect java + oracle db with jdbc, but there i get the same error.</p>
  
  <p>Here are my listener.ora </p>
  
  <pre><code># listener.ora Network Configuration File:
  
  SID_LIST_LISTENER =
    (SID_LIST =
      (SID_DESC =
        (SID_NAME = PLSExtProc)
        (ORACLE_HOME = /u01/app/oracle/product/11.2.0/xe)
        (PROGRAM = extproc)
      )
    )
  
  LISTENER =
    (DESCRIPTION_LIST =
      (DESCRIPTION =
        (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC_FOR_XE))
        (ADDRESS = (PROTOCOL = TCP)(HOST = watson)(PORT = 1521))
      )
    )
  
  DEFAULT_SERVICE_LISTENER = (XE)
  </code></pre>
  
  <p>and tnsnames.ora </p>
  
  <pre><code># tnsnames.ora Network Configuration File:
  
  XE =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = watson)(PORT = 1521))
      (CONNECT_DATA =
        (SERVER = DEDICATED)
        (SERVICE_NAME = XE)
      )
    )
  
  EXTPROC_CONNECTION_DATA =
    (DESCRIPTION =
      (ADDRESS_LIST =
        (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC_FOR_XE))
      )
      (CONNECT_DATA =
        (SID = PLSExtProc)
        (PRESENTATION = RO)
      )
    )
  </code></pre>
  
  <p>and </p>
  
  <pre><code>lsnrctl service
  
  LSNRCTL for Linux: Version 11.2.0.2.0 - Production on 04-FEB-2014 17:01:44
  Copyright (c) 1991, 2011, Oracle.  All rights reserved.
  Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC_FOR_XE)))
  Services Summary...
  Service "PLSExtProc" has 1 instance(s).
    Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
      Handler(s):
        "DEDICATED" established:0 refused:0
           LOCAL SERVER
  The command completed successfully
  </code></pre>