[TAP] Auto deregister at servlet destruction the JDBC driver loaded by the...

import static tap.config.TAPConfiguration.VALUE_USER_ACTION;

import static tap.config.TAPConfiguration.getProperty;

import java.sql.Driver;

import java.sql.DriverManager;

import java.sql.SQLException;

import java.util.Enumeration;

import java.util.Properties;

import javax.naming.InitialContext;

import uws.UWSException;

import uws.service.UWSService;

import uws.service.backup.UWSBackupManager;

import uws.service.log.UWSLog.LogLevel;

import adql.translator.JDBCTranslator;

import adql.translator.PgSphereTranslator;

import adql.translator.PostgreSQLTranslator;

	@Override

	public void destroy(){

		// Unregister the JDBC driver:

		// Unregister the JDBC driver, only if registered by the library (i.e. database_access=jdbc):

		if (dbUrl != null){

			// Now deregister JDBC drivers in this context's ClassLoader:

			// Get the webapp's ClassLoader

			ClassLoader cl = Thread.currentThread().getContextClassLoader();

			// Loop through all drivers

			Enumeration<Driver> drivers = DriverManager.getDrivers();

			while(drivers.hasMoreElements()){

				Driver driver = drivers.nextElement();

				if (driver.getClass().getClassLoader() == cl){

					// This driver was registered by the webapp's ClassLoader, so deregister it:

					try{

			DriverManager.deregisterDriver(DriverManager.getDriver(dbUrl));

		}catch(SQLException e){

			service.getLogger().warning("Can not deregister the JDBC driver manager!");

						DriverManager.deregisterDriver(driver);

						service.getLogger().logTAP(LogLevel.INFO, null, "STOP", "JDBC driver " + driver.getClass().getName() + " successfully deregistered!", null);

					}catch(SQLException ex){

						service.getLogger().logTAP(LogLevel.FATAL, null, "STOP", "Error deregistering JDBC driver " + driver.getClass().getName() + "!", ex);

					}

				}

			}

		}

		// TODO Nothing else to do!

	}

	/**