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

Caused by: java.sql.SQLException: Io exception: The Network Adapter could not establish the connection
 at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:112)
 at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:146)
 at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:255)
 at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:387)
 at oracle.jdbc.driver.PhysicalConnection.(PhysicalConnection.java:420)
 at oracle.jdbc.driver.T4CConnection.(T4CConnection.java:165)
 at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:35)
 at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:801)
 at oracle.jdbc.pool.OracleDataSource.getPhysicalConnection(OracleDataSource.java:297)
 at oracle.jdbc.pool.OracleDataSource.getConnection(OracleDataSource.java:221)
 at oracle.jdbc.pool.OracleConnectionPoolDataSource.getPhysicalConnection(OracleConnectionPoolDataSource.java:157)
 at oracle.jdbc.pool.OracleConnectionPoolDataSource.getPooledConnection(OracleConnectionPoolDataSource.java:94)
 at oracle.jdbc.pool.OracleConnectionPoolDataSource.getPooledConnection(OracleConnectionPoolDataSource.java:75)
 at com.sun.gjc.spi.CPManagedConnectionFactory.createManagedConnection(CPManagedConnectionFactory.java:133)
 ... 99 more