java.sql.SQLException: Io exception: The Network Adapter could not establish the connection

at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:111)

at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:145)

at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:254)

at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:386)

at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:438)