initializerservletcontextlistener.java

来自「opennms得相关源码 请大家看看」· Java 代码 · 共 147 行

//
//  $Id: InitializerServletContextListener.java 1199 2004-11-21 03:31:16Z brozow $
//
// This file is part of the OpenNMS(R) Application.
//
// OpenNMS(R) is Copyright (C) 2002-2003 The OpenNMS Group, Inc.  All
// rights reserved.
// OpenNMS(R) is a derivative work, containing both original code,
// included code and modified code that was published under the GNU
// General Public License. Copyrights for modified and included code
// are below.
//
// OpenNMS(R) is a registered trademark of The OpenNMS Group, Inc.
//
// Copyright (C) 1999-2001 Oculan Corp.  All rights reserved.
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
//
// For more information contact:
//      OpenNMS Licensing       <[e-mail]>
//      http://www.opennms.org/
//      http://www.opennms.com/
//

package org.opennms.web;

import java.lang.reflect.UndeclaredThrowableException;
import java.net.ConnectException;
import java.util.Date;
import java.util.Timer;
import java.util.TimerTask;

import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.ServletException;

import org.opennms.web.category.CategoryList;
import org.opennms.web.category.RTCPostSubscriber;

/**
 * Initializes our internal servlet systems at servlet container startup, and
 * destroys any pool resources at servlet container shutdown.
 * 
 * This listener is specified in the web.xml to listen to
 * <code>ServletContext</code> lifecyle events. On startup it calls
 * ServletInitializer.init and initializes the UserFactory, GroupFactory. On
 * shutdown it calls ServletInitializer.destroy.
 * 
 * @author <A HREF="mailto:[e-mail]">Lawrence Karnowski </A>
 * @author <A HREF="http://www.opennms.org/">OpenNMS </A>
 */
public class InitializerServletContextListener implements ServletContextListener {

    private Timer rtcCheckTimer = null;

    public void contextInitialized(ServletContextEvent event) {
        ServletContext context = event.getServletContext();

        try {
            // Initialize the scarce resource policies (db connections) and
            // common configuration.
            ServletInitializer.init(context);

            context.log("[InitializerServletContextListener] Initialized " + "servlet systems successfully");
        } catch (ServletException e) {
            context.log("[InitializerServletContextListener] Error while " + "initializing servlet systems", e);
        } catch (Exception e) {
            context.log("[InitializerServletContextListener] Error while " + "initializing user, group, or view factory", e);
        }

        try {
            rtcCheckTimer = new Timer();
            rtcCheckTimer.schedule(new RTCPostSubscriberTimerTask(context), new Date(), 130000);
        } catch (ServletException e) {
            context.log("[InitializerServletContextListener] Error while " + "initializing RTC check timer", e);
        }
    }

    public void contextDestroyed(ServletContextEvent event) {
        ServletContext context = event.getServletContext();

        try {
            // Let the scarce resource policies release any shared
            // resouces (db connections).
            ServletInitializer.destroy(event.getServletContext());

            // Report success.
            context.log("[InitializerServletContextListener] Destroyed " + "servlet systems successfully");
        } catch (ServletException e) {
            context.log("[InitializerServletContextListener] Error while " + "destroying servlet systems", e);
        }

        if (rtcCheckTimer != null) {
            rtcCheckTimer.cancel();
            rtcCheckTimer = null;
        }
    }

    public class RTCPostSubscriberTimerTask extends TimerTask {
        private ServletContext m_context;

        private CategoryList m_categorylist;

        public RTCPostSubscriberTimerTask(ServletContext context) throws ServletException {
            m_context = context;
            m_categorylist = new CategoryList(m_context);
        }

        public void run() {
            try {
                if (!m_categorylist.isDisconnected()) {
                    return;
                }
            } catch (Exception e) {
                m_context.log("[RTCPostSubscriberTimerTask] Error checking " + "if OpenNMS is disconnected", e);
                return;
            }

            m_context.log("[RTCPostSubscriberTimerTask] OpenNMS is " + "disconnected -- attempting RTC POST subscription");

            try {
                RTCPostSubscriber.subscribeAll("WebConsoleView");
                m_context.log("[RTCPostSubscriberTimerTask] RTC POST " + "subscription event sent successfully");
            } catch (Exception e) {
                if (UndeclaredThrowableException.class.isInstance(e) && e.getCause() != null && ConnectException.class.isInstance(e.getCause())) {
                    m_context.log("[RTCPostSubscriberTimerTask] RTC POST " + "failed due to ConnectException: " + e.getCause().toString());
                } else {
                    m_context.log("[RTCPostSubscriberTimerTask] Error " + "subscribing to RTC POSTs", e);
                }
            }
        }
    }
}