dk.netarkivet.archive.bitarchive.distribute.HeartBeatSender.java Source code

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Here is the source code for dk.netarkivet.archive.bitarchive.distribute.HeartBeatSender.java

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/* File:        $Id$
 * Revision:    $Revision$
 * Author:      $Author$
 * Date:        $Date$
 *
 * The Netarchive Suite - Software to harvest and preserve websites
 * Copyright 2004-2012 The Royal Danish Library, the Danish State and
 * University Library, the National Library of France and the Austrian
 * National Library.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 
 *  USA
 */
package dk.netarkivet.archive.bitarchive.distribute;

import java.util.TimerTask;

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

import dk.netarkivet.common.distribute.ChannelID;
import dk.netarkivet.common.distribute.JMSConnection;
import dk.netarkivet.common.distribute.JMSConnectionFactory;
import dk.netarkivet.common.exceptions.ArgumentNotValid;
import dk.netarkivet.common.exceptions.IOFailure;

/**
 * Thread reponsible for sending out periodic HeartBeatMessages.
 * The BitarchiveServer is closed down if any error occurs
 * whilst sending heartbeats.
 *
 */
public class HeartBeatSender extends TimerTask {
    /** The log.*/
    private final Log log = LogFactory.getLog(this.getClass().getName());
    /** the receiver to receive heartbeats. */
    private ChannelID receiver;
    /** the BitarchiveServer of this HeartBeatSender. */
    private BitarchiveServer baServer;
    /** the id of the application sending the heartbeat message. */
    private String applicationId;
    /** the connection to use when sending heartbeats. */
    private JMSConnection con;

    /**
     * Constructs a HearBeatSender that sends heartbeats.
     *
     * @param inReceiver  - the receiver to receive the heartbeats
     * @param inBaServer  - the BitarchiveServer of this HeartBeatSender
     * @throws ArgumentNotValid - if in_baServer is null
     * @throws IOFailure        - if getting an JMSConnection instance fails
     */
    public HeartBeatSender(ChannelID inReceiver, BitarchiveServer inBaServer) throws ArgumentNotValid, IOFailure {
        ArgumentNotValid.checkNotNull(inBaServer, "inBaServer");
        receiver = inReceiver;
        applicationId = inBaServer.getBitarchiveAppId();
        baServer = inBaServer;
        con = JMSConnectionFactory.getInstance();
    }

    /**
     * This is the run method of the thread sending heartbeats.
     * The BitarchiveServer is closed down if any error occurs.
     */
    public void run() {
        try {
            con.send(new HeartBeatMessage(receiver, applicationId));
        } catch (Throwable t) {
            log.fatal("An unexpected error occurred." + "BitarchiveServer couldn't ping BitarchiveMonitorServer.",
                    t);
        }
    }

    /**
     * Retrieval of a string representation of this instance.
     * 
     * @return The string representation of this instance.
     */
    public String toString() {
        return super.toString() + ", Receiver: " + receiver + ", BitArchiveServer: " + baServer.toString();
    }
}