broadcasteventprocessor.java

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//
// 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.
//
// Modifications:
//
// 2003 Jan 31: Cleaned up some unused imports.
//
// Original code base 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/
//
// Tab Size = 8
//

package org.opennms.netmgt.discovery;

import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.List;

import org.apache.log4j.Category;
import org.opennms.core.utils.ThreadCategory;
import org.opennms.netmgt.EventConstants;
import org.opennms.netmgt.eventd.EventIpcManagerFactory;
import org.opennms.netmgt.eventd.EventListener;
import org.opennms.netmgt.xml.event.Event;

/**
 * 
 * @author <a href="mailto:[e-mail]">Brian Weaver </a>
 * @author <a href="http://www.opennms.org/">OpenNMS </a>
 */
final class BroadcastEventProcessor implements EventListener {
    /**
     * Create message selector to set to the subscription
     */
    BroadcastEventProcessor() {
        // Create the selector for the ueis this service is interested in
        //
        List ueiList = new ArrayList();

        // nodeGainedInterface
        ueiList.add(EventConstants.NODE_GAINED_INTERFACE_EVENT_UEI);

        // discPause
        ueiList.add(EventConstants.DISC_PAUSE_EVENT_UEI);

        // discResume
        ueiList.add(EventConstants.DISC_RESUME_EVENT_UEI);

        // interfaceDeleted
        ueiList.add(EventConstants.INTERFACE_DELETED_EVENT_UEI);

        EventIpcManagerFactory.init();
        EventIpcManagerFactory.getInstance().getManager().addEventListener(this, ueiList);
    }

    /**
     * Unsubscribe from eventd
     */
    public void close() {
        EventIpcManagerFactory.getInstance().getManager().removeEventListener(this);
    }

    /**
     * This method is invoked by the EventIpcManager when a new event is
     * available for processing. Each message is examined for its Universal
     * Event Identifier and the appropriate action is taking based on each UEI.
     * 
     * @param event
     *            The event
     * 
     */
    public void onEvent(Event event) {
        Category log = ThreadCategory.getInstance(getClass());

        String eventUei = event.getUei();
        if (eventUei == null)
            return;

        if (log.isDebugEnabled())
            log.debug("Received event: " + eventUei);

        if (eventUei.equals(EventConstants.NODE_GAINED_INTERFACE_EVENT_UEI)) {
            // add to known nodes
            try {
                DiscoveredIPMgr.addDiscovered(event.getInterface());
            } catch (UnknownHostException uhE) {
                ThreadCategory.getInstance(getClass()).warn("Failed to add interface " + event.getInterface() + " to discovered address set", uhE);
            }

            if (log.isDebugEnabled())
                log.debug("Added " + event.getInterface() + " as discovered");
        } else if (eventUei.equals(EventConstants.DISC_PAUSE_EVENT_UEI)) {
            try {
                Discovery.getInstance().pause();
            } catch (IllegalStateException ex) {
            }
        } else if (eventUei.equals(EventConstants.DISC_RESUME_EVENT_UEI)) {
            try {
                Discovery.getInstance().resume();
            } catch (IllegalStateException ex) {
            }
        } else if (eventUei.equals(EventConstants.INTERFACE_DELETED_EVENT_UEI)) {
            // remove from known nodes
            try {
                DiscoveredIPMgr.removeDiscovered(event.getInterface());
            } catch (UnknownHostException uhE) {
                ThreadCategory.getInstance(getClass()).warn("Failed to remove interface " + event.getInterface() + " from discovered address set", uhE);
            }

            if (log.isDebugEnabled())
                log.debug("Removed " + event.getInterface() + " from known node list");
        }
    }

    /**
     * Return an id for this event listener
     */
    public String getName() {
        return "Discovery:BroadcastEventProcessor";
    }
}