quartzscheduler.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.core;

import java.rmi.RemoteException;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
import java.rmi.server.UnicastRemoteObject;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Random;
import java.util.Set;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.quartz.Calendar;
import org.quartz.Job;
import org.quartz.InterruptableJob;
import org.quartz.JobDetail;
import org.quartz.JobExecutionContext;
import org.quartz.JobExecutionException;
import org.quartz.JobListener;
import org.quartz.JobPersistenceException;
import org.quartz.ObjectAlreadyExistsException;
import org.quartz.Scheduler;
import org.quartz.SchedulerContext;
import org.quartz.SchedulerException;
import org.quartz.SchedulerListener;
import org.quartz.Trigger;
import org.quartz.TriggerListener;
import org.quartz.UnableToInterruptJobException;
import org.quartz.impl.SchedulerRepository;
import org.quartz.spi.SchedulerPlugin;
import org.quartz.spi.SchedulerSignaler;

/**
 * <p>
 * This is the heart of Quartz, an indirect implementation of the <code>{@link org.quartz.Scheduler}</code>
 * interface, containing methods to schedule <code>{@link org.quartz.Job}</code>s,
 * register <code>{@link org.quartz.JobListener}</code> instances, etc.
 * </p>// TODO: more docs...
 * 
 * @see org.quartz.Scheduler
 * @see org.quartz.core.QuartzSchedulerThread
 * @see org.quartz.spi.JobStore
 * @see org.quartz.spi.ThreadPool
 * 
 * @author James House
 */
public class QuartzScheduler implements RemotableQuartzScheduler {

    /*
     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     * 
     * Constants.
     * 
     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     */

    public static final String VERSION_MAJOR = "@version.major@";

    public static final String VERSION_MINOR = "@version.minor@";

    public static final String VERSION_ITERATION = "@version.iteration@";

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

    private QuartzSchedulerResources resources;

    private QuartzSchedulerThread schedThread;

    private ThreadGroup threadGroup;

    private SchedulerContext context = new SchedulerContext();

    private HashMap jobListeners = new HashMap(10);

    private ArrayList globalJobListeners = new ArrayList(10);

    private HashMap triggerListeners = new HashMap(10);

    private ArrayList globalTriggerListeners = new ArrayList(10);

    private ArrayList schedulerListeners = new ArrayList(10);

    private ArrayList schedulerPlugins = new ArrayList(10);

    ExecutingJobsManager jobMgr = null;

    ErrorLogger errLogger = null;

    private SchedulerSignaler signaler;

    private Random random = new Random();

    private ArrayList holdToPreventGC = new ArrayList(5);

    private boolean signalOnSchedulingChange = true;

    private boolean closed = false;

    private Date initialStart = null;

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

    /**
     * <p>
     * Create a <code>QuartzScheduler</code> with the given configuration
     * properties.
     * </p>
     * 
     * @see QuartzSchedulerResources
     */
    public QuartzScheduler(QuartzSchedulerResources resources,
            SchedulingContext ctxt, long idleWaitTime, long dbRetryInterval)
            throws SchedulerException {
        this.resources = resources;
        try {
            bind();
        } catch (Exception re) {
            throw new SchedulerException(
                    "Unable to bind scheduler to RMI Registry.", re);
        }

        this.schedThread = new QuartzSchedulerThread(this, resources, ctxt);
        if (idleWaitTime > 0) this.schedThread.setIdleWaitTime(idleWaitTime);
        if (dbRetryInterval > 0)
                this.schedThread.setDbFailureRetryInterval(dbRetryInterval);

        jobMgr = new ExecutingJobsManager();
        addGlobalJobListener(jobMgr);
        errLogger = new ErrorLogger();
        addSchedulerListener(errLogger);

        signaler = new SchedulerSignalerImpl(this);
    }

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

    public String getVersion() {
        return getVersionMajor() + "." + getVersionMinor() + "."
                + getVersionIteration();
    }

    public String getVersionMajor() {
        return VERSION_MAJOR;
    }

    public String getVersionMinor() {
        return VERSION_MINOR;
    }

    public String getVersionIteration() {
        return VERSION_ITERATION;
    }

    public SchedulerSignaler getSchedulerSignaler() {
        return signaler;
    }

    public static Log getLog() {
        return LogFactory.getLog(QuartzScheduler.class);
    }

    /**
     * <p>
     * Bind the scheduler to an RMI registry.
     * </p>
     */
    private void bind() throws RemoteException {
        String host = resources.getRMIRegistryHost();
        // don't export if we're not configured to do so...
        if (host == null || host.length() == 0) return;

        RemotableQuartzScheduler exportable = (RemotableQuartzScheduler) UnicastRemoteObject
                .exportObject(this);

        Registry registry = null;

        if (resources.getRMICreateRegistryStrategy().equals(
                QuartzSchedulerResources.CREATE_REGISTRY_AS_NEEDED)) {
            try {
                // First try to get an existing one, instead of creating it,
                // since if
                // we're in a web-app being 'hot' re-depoloyed, then the JVM
                // still
                // has the registry that we created above the first time...
                registry = LocateRegistry.getRegistry(resources
                        .getRMIRegistryPort());
                registry.list();
            } catch (Exception e) {
                registry = LocateRegistry.createRegistry(resources
                        .getRMIRegistryPort());
            }
        } else if (resources.getRMICreateRegistryStrategy().equals(
                QuartzSchedulerResources.CREATE_REGISTRY_ALWAYS)) {
            try {
                registry = LocateRegistry.createRegistry(resources
                        .getRMIRegistryPort());
            } catch (Exception e) {
                // Fall back to an existing one, instead of creating it, since
                // if
                // we're in a web-app being 'hot' re-depoloyed, then the JVM
                // still
                // has the registry that we created above the first time...
                registry = LocateRegistry.getRegistry(resources
                        .getRMIRegistryPort());
            }
        } else {
            registry = LocateRegistry.getRegistry(resources
                    .getRMIRegistryHost(), resources.getRMIRegistryPort());
        }

        registry.rebind(resources.getUniqueIdentifier(), exportable);

        getLog().info("Scheduler bound to RMI registry.");
    }

    /**
     * <p>
     * Un-bind the scheduler from an RMI registry.
     * </p>
     */
    private void unBind() throws RemoteException {
        String host = resources.getRMIRegistryHost();
        // don't un-export if we're not configured to do so...
        if (host == null || host.length() == 0) return;

        Registry registry = LocateRegistry.getRegistry(resources
                .getRMIRegistryHost(), resources.getRMIRegistryPort());

        try {
            registry.unbind(resources.getUniqueIdentifier());
            UnicastRemoteObject.unexportObject(this, true);
        } catch (java.rmi.NotBoundException nbe) {
        }

        getLog().info("Scheduler un-bound from RMI registry.");
    }

    /**
     * <p>
     * Returns the name of the <code>QuartzScheduler</code>.
     * </p>
     */
    public String getSchedulerName() {
        return resources.getName();
    }

    /**
     * <p>
     * Returns the instance Id of the <code>QuartzScheduler</code>.
     * </p>
     */
    public String getSchedulerInstanceId() {
        return resources.getInstanceId();
    }

    /**
     * <p>
     * Returns the name of the <code>QuartzScheduler</code>.
     * </p>
     */
    public ThreadGroup getSchedulerThreadGroup() {
        if (threadGroup == null) {
            threadGroup = new ThreadGroup("QuartzScheduler:"
                    + getSchedulerName());
        }

        return threadGroup;
    }

    public void addNoGCObject(Object obj) {
        holdToPreventGC.add(obj);
    }

    public boolean removeNoGCObject(Object obj) {
        return holdToPreventGC.remove(obj);
    }

    /**
     * <p>
     * Returns the <code>SchedulerContext</code> of the <code>Scheduler</code>.
     * </p>
     */
    public SchedulerContext getSchedulerContext() throws SchedulerException {
        return context;
    }

    public boolean isSignalOnSchedulingChange() {
        return signalOnSchedulingChange;
    }

    public void setSignalOnSchedulingChange(boolean signalOnSchedulingChange) {
        this.signalOnSchedulingChange = signalOnSchedulingChange;
    }

    ///////////////////////////////////////////////////////////////////////////
    ///
    /// Schedululer State Management Methods
    ///
    ///////////////////////////////////////////////////////////////////////////

    /**
     * <p>
     * Starts the <code>QuartzScheduler</code>'s threads that fire <code>{@link org.quartz.Trigger}s</code>.
     * </p>
     * 
     * <p>
     * All <code>{@link org.quartz.Trigger}s</code> that have misfired will
     * be passed to the appropriate TriggerListener(s).
     * </p>
     */
    public void start() throws SchedulerException {

        if (closed)
                throw new SchedulerException(
                        "The Scheduler cannot be restarted after shutdown() has been called.");

        schedThread.togglePause(false);

        if (initialStart == null) {
            initialStart = new Date();
            startPlugins();
        }

        getLog().info(
                "Scheduler " + resources.getUniqueIdentifier() + " started.");
    }

    /**
     * <p>
     * Temporarily halts the <code>QuartzScheduler</code>'s firing of <code>{@link org.quartz.Trigger}s</code>.
     * </p>
     * 
     * <p>
     * The scheduler is not destroyed, and can be re-started at any time.
     * </p>
     */
    public void pause() {
        schedThread.togglePause(true);
        getLog().info(
                "Scheduler " + resources.getUniqueIdentifier() + " paused.");
    }

    /**
     * <p>
     * Reports whether the <code>Scheduler</code> is paused.
     * </p>
     */