eionet.meta.ContainerContextClosedHandler.java Source code

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Here is the source code for eionet.meta.ContainerContextClosedHandler.java

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/*
 * The contents of this file are subject to the Mozilla Public
 * License Version 1.1 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * The Original Code is Data Dictionary
 *
 * The Initial Owner of the Original Code is European Environment
 * Agency. Portions created by TripleDev are Copyright
 * (C) European Environment Agency.  All Rights Reserved.
 *
 * Contributor(s):
 *        TripleDev
 */
package eionet.meta;

import java.sql.Driver;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Enumeration;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.mysql.jdbc.AbandonedConnectionCleanupThread;

/**
 * Class to close database connections to prevent memory leaks.
 *
 * @author enver
 */
public class ContainerContextClosedHandler implements ServletContextListener {

    /** Logger instance. */
    private static final Log LOGGER = LogFactory.getLog(ContainerContextClosedHandler.class);

    @Override
    public void contextInitialized(ServletContextEvent servletContextEvent) {
        // nothing to do
    }

    /**
     * Unregisters mysql connections.
     *
     * @param servletContextEvent
     *            servlet context
     */
    @Override
    public void contextDestroyed(ServletContextEvent servletContextEvent) {
        Enumeration<Driver> drivers = DriverManager.getDrivers();

        Driver driver = null;

        // clear drivers
        while (drivers.hasMoreElements()) {
            try {
                driver = drivers.nextElement();
                DriverManager.deregisterDriver(driver);
            } catch (SQLException ex) {
                // deregistration failed
                LOGGER.warn(ex.getMessage());
            }
        }

        // MySQL driver leaves around a thread. This static method cleans it up.
        try {
            // throw new InterruptedException();
            AbandonedConnectionCleanupThread.shutdown();
        } catch (InterruptedException ex) {
            // again failure
            LOGGER.warn(ex.getMessage());
        }
    } // end of method contextDestroyed

} // end of class ContainerContextClosedHandler