title: Can't connect to Oracle database from application
body: <p>after restarting operating system (aix) I am not able to connect to locally installed oracle db from my application.</p>
  
  <p>connected to sqlplus and executed startup command. </p>
  
  <p>Select statements working fine from sqlplus. Should we start listener separately?</p>
  
  <p>But the application fails with:</p>
  
  <pre><code>Error:
  IO Error: The Network Adapter could not establish the connection
  Caused by: Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.6.1.v20150916-55dc7c3): org.eclipse.persistence.exceptions.DatabaseException
  Internal Exception: java.sql.SQLRecoverableException: IO Error: The Network Adapter could not establish the connection
  </code></pre>