shutdownhookplugin.java

定时器开源项目, 相对于 jcrontab, Quartz 算是更完整的一个项目, 随著开发的版本上来, 他已经脱离只是写在程序里面的计时器, 在指定的时间或区间, 处理所指定的事件. 也加入了 se

/*
 * Copyright James House (c) 2001-2004
 * 
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met: 1.
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer. 2. Redistributions in
 * binary form must reproduce the above copyright notice, this list of
 * conditions and the following disclaimer in the documentation and/or other
 * materials provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *  
 */
package org.quartz.plugins.management;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.quartz.Scheduler;
import org.quartz.SchedulerException;
import org.quartz.spi.SchedulerPlugin;

/**
 * This plugin catches the event of the JVM terminating (such as upon a CRTL-C)
 * and tells the scheuler to shutdown.
 * 
 * @see org.quartz.Scheduler#shutdown(boolean)
 * 
 * @author James House
 */
public class ShutdownHookPlugin implements SchedulerPlugin {

    /*
     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     * 
     * Data members.
     * 
     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     */

    private String name;

    private Scheduler scheduler;

    private boolean cleanShutdown = true;

    /*
     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     * 
     * Constructors.
     * 
     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     */

    public ShutdownHookPlugin() {
    }

    /*
     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     * 
     * Interface.
     * 
     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     */

    /**
     * Determine whether or not the plug-in is configured to cause a clean
     * shutdown of the scheduler.
     * 
     * <p>
     * The default value is <code>true</code>.
     * </p>
     * 
     * @see org.quartz.Scheduler#shutdown(boolean)
     */
    public boolean isCleanShutdown() {
        return cleanShutdown;
    }

    /**
     * Set whether or not the plug-in is configured to cause a clean shutdown
     * of the scheduler.
     * 
     * <p>
     * The default value is <code>true</code>.
     * </p>
     * 
     * @see org.quartz.Scheduler#shutdown(boolean)
     */
    public void setCleanShutdown(boolean b) {
        cleanShutdown = b;
    }

    protected static Log getLog() {
        return LogFactory.getLog(ShutdownHookPlugin.class);
    }

    /*
     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     * 
     * SchedulerPlugin Interface.
     * 
     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     */

    /**
     * <p>
     * Called during creation of the <code>Scheduler</code> in order to give
     * the <code>SchedulerPlugin</code> a chance to initialize.
     * </p>
     * 
     * @throws SchedulerConfigException
     *           if there is an error initializing.
     */
    public void initialize(String name, final Scheduler scheduler)
            throws SchedulerException {
        this.name = name;
        this.scheduler = scheduler;

        getLog().info("Registering Quartz shutdown hook.");

        Thread t = new Thread("Quartz Shutdown-Hook "
                + scheduler.getSchedulerName()) {
            public void run() {
                getLog().info("Shutting down Quartz...");
                try {
                    scheduler.shutdown(isCleanShutdown());
                } catch (SchedulerException e) {
                    getLog().info(
                            "Error shutting down Quartz: " + e.getMessage(), e);
                }
            }
        };

        Runtime.getRuntime().addShutdownHook(t);
    }

    public void start() {
        // do nothing.
    }

    /**
     * <p>
     * Called in order to inform the <code>SchedulerPlugin</code> that it
     * should free up all of it's resources because the scheduler is shutting
     * down.
     * </p>
     */
    public void shutdown() {
        // nothing to do in this case (since the scheduler is already shutting
        // down)
    }

}

// EOF