crontrigger.java

Quartz 是个开源的作业调度框架

/* 
 * Copyright 2004-2005 OpenSymphony 
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not 
 * use this file except in compliance with the License. You may obtain a copy 
 * of the License at 
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0 
 *   
 * Unless required by applicable law or agreed to in writing, software 
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 
 * License for the specific language governing permissions and limitations 
 * under the License.
 * 
 */

/*
 * Previously Copyright (c) 2001-2004 James House
 */
package org.quartz;

import java.text.ParseException;
import java.util.Calendar;
import java.util.Date;
import java.util.TimeZone;


/**
 * <p>
 * A concrete <code>{@link Trigger}</code> that is used to fire a <code>{@link org.quartz.JobDetail}</code>
 * at given moments in time, defined with Unix 'cron-like' definitions.
 * </p>
 * 
 * <p>
 * For those unfamiliar with "cron", this means being able to create a firing
 * schedule such as: "At 8:00am every Monday through Friday" or "At 1:30am
 * every last Friday of the month".
 * </p>
 * 
 * <p>
 * The format of a "Cron-Expression" string is documented on the 
 * {@link org.quartz.CronExpression} class.
 * </p>
 * 
 * <p>
 * Here are some full examples: <br><table cellspacing="8">
 * <tr>
 * <th align="left">Expression</th>
 * <th align="left">&nbsp;</th>
 * <th align="left">Meaning</th>
 * </tr>
 * <tr>
 * <td align="left"><code>"0 0 12 * * ?"</code></td>
 * <td align="left">&nbsp;</th>
 * <td align="left"><code>Fire at 12pm (noon) every day</code></td>
 * </tr>
 * <tr>
 * <td align="left"><code>"0 15 10 ? * *"</code></td>
 * <td align="left">&nbsp;</th>
 * <td align="left"><code>Fire at 10:15am every day</code></td>
 * </tr>
 * <tr>
 * <td align="left"><code>"0 15 10 * * ?"</code></td>
 * <td align="left">&nbsp;</th>
 * <td align="left"><code>Fire at 10:15am every day</code></td>
 * </tr>
 * <tr>
 * <td align="left"><code>"0 15 10 * * ? *"</code></td>
 * <td align="left">&nbsp;</th>
 * <td align="left"><code>Fire at 10:15am every day</code></td>
 * </tr>
 * <tr>
 * <td align="left"><code>"0 15 10 * * ? 2005"</code></td>
 * <td align="left">&nbsp;</th>
 * <td align="left"><code>Fire at 10:15am every day during the year 2005</code>
 * </td>
 * </tr>
 * <tr>
 * <td align="left"><code>"0 * 14 * * ?"</code></td>
 * <td align="left">&nbsp;</th>
 * <td align="left"><code>Fire every minute starting at 2pm and ending at 2:59pm, every day</code>
 * </td>
 * </tr>
 * <tr>
 * <td align="left"><code>"0 0/5 14 * * ?"</code></td>
 * <td align="left">&nbsp;</th>
 * <td align="left"><code>Fire every 5 minutes starting at 2pm and ending at 2:55pm, every day</code>
 * </td>
 * </tr>
 * <tr>
 * <td align="left"><code>"0 0/5 14,18 * * ?"</code></td>
 * <td align="left">&nbsp;</th>
 * <td align="left"><code>Fire every 5 minutes starting at 2pm and ending at 2:55pm, AND fire every 5 minutes starting at 6pm and ending at 6:55pm, every day</code>
 * </td>
 * </tr>
 * <tr>
 * <td align="left"><code>"0 0-5 14 * * ?"</code></td>
 * <td align="left">&nbsp;</th>
 * <td align="left"><code>Fire every minute starting at 2pm and ending at 2:05pm, every day</code>
 * </td>
 * </tr>
 * <tr>
 * <td align="left"><code>"0 10,44 14 ? 3 WED"</code></td>
 * <td align="left">&nbsp;</th>
 * <td align="left"><code>Fire at 2:10pm and at 2:44pm every Wednesday in the month of March.</code>
 * </td>
 * </tr>
 * <tr>
 * <td align="left"><code>"0 15 10 ? * MON-FRI"</code></td>
 * <td align="left">&nbsp;</th>
 * <td align="left"><code>Fire at 10:15am every Monday, Tuesday, Wednesday, Thursday and Friday</code>
 * </td>
 * </tr>
 * <tr>
 * <td align="left"><code>"0 15 10 15 * ?"</code></td>
 * <td align="left">&nbsp;</th>
 * <td align="left"><code>Fire at 10:15am on the 15th day of every month</code>
 * </td>
 * </tr>
 * <tr>
 * <td align="left"><code>"0 15 10 L * ?"</code></td>
 * <td align="left">&nbsp;</th>
 * <td align="left"><code>Fire at 10:15am on the last day of every month</code>
 * </td>
 * </tr>
 * <tr>
 * <td align="left"><code>"0 15 10 ? * 6L"</code></td>
 * <td align="left">&nbsp;</th>
 * <td align="left"><code>Fire at 10:15am on the last Friday of every month</code>
 * </td>
 * </tr>
 * <tr>
 * <td align="left"><code>"0 15 10 ? * 6L"</code></td>
 * <td align="left">&nbsp;</th>
 * <td align="left"><code>Fire at 10:15am on the last Friday of every month</code>
 * </td>
 * </tr>
 * <tr>
 * <td align="left"><code>"0 15 10 ? * 6L 2002-2005"</code></td>
 * <td align="left">&nbsp;</th>
 * <td align="left"><code>Fire at 10:15am on every last friday of every month during the years 2002, 2003, 2004 and 2005</code>
 * </td>
 * </tr>
 * <tr>
 * <td align="left"><code>"0 15 10 ? * 6#3"</code></td>
 * <td align="left">&nbsp;</th>
 * <td align="left"><code>Fire at 10:15am on the third Friday of every month</code>
 * </td>
 * </tr>
 * </table>
 * </p>
 * 
 * <p>
 * Pay attention to the effects of '?' and '*' in the day-of-week and
 * day-of-month fields!
 * </p>
 * 
 * <p>
 * <b>NOTES:</b>
 * <ul>
 * <li>Support for specifying both a day-of-week and a day-of-month value is
 * not complete (you'll need to use the '?' character in on of these fields).
 * </li>
 * <li>Be careful when setting fire times between mid-night and 1:00 AM -
 * "daylight savings" can cause a skip or a repeat depending on whether the
 * time moves back or jumps forward.</li>
 * </ul>
 * </p>
 * 
 * @see Trigger
 * @see SimpleTrigger
 * @see TriggerUtils
 * 
 * @author Sharada Jambula, James House
 * @author Contributions from Mads Henderson
 */
public class CronTrigger extends Trigger {

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

    /**
     * <p>
     * Instructs the <code>{@link Scheduler}</code> that upon a mis-fire
     * situation, the <code>{@link CronTrigger}</code> wants to be fired now
     * by <code>Scheduler</code>.
     * </p>
     */
    public static final int MISFIRE_INSTRUCTION_FIRE_ONCE_NOW = 1;

    /**
     * <p>
     * Instructs the <code>{@link Scheduler}</code> that upon a mis-fire
     * situation, the <code>{@link CronTrigger}</code> wants to have it's
     * next-fire-time updated to the next time in the schedule after the
     * current time (taking into account any associated <code>{@link Calendar}</code>,
     * but it does not want to be fired now.
     * </p>
     */
    public static final int MISFIRE_INSTRUCTION_DO_NOTHING = 2;

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

    private CronExpression cronEx = null;
    private Date startTime = null;
    private Date endTime = null;
    private Date nextFireTime = null;
    private Date previousFireTime = null;
    private transient TimeZone timeZone = null;

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

    /**
     * <p>
     * Create a <code>CronTrigger</code> with no settings.
     * </p>
     * 
     * <p>
     * The start-time will also be set to the current time, and the time zone
     * will be set the the system's default time zone.
     * </p>
     */
    public CronTrigger() {
        super();
        setStartTime(new Date());
        setTimeZone(TimeZone.getDefault());
    }

    /**
     * <p>
     * Create a <code>CronTrigger</code> with the given name and group.
     * </p>
     * 
     * <p>
     * The start-time will also be set to the current time, and the time zone
     * will be set the the system's default time zone.
     * </p>
     */
    public CronTrigger(String name, String group) {
        super(name, group);
        setStartTime(new Date());
        setTimeZone(TimeZone.getDefault());
    }

    /**
     * <p>
     * Create a <code>CronTrigger</code> with the given name, group and
     * expression.
     * </p>
     * 
     * <p>
     * The start-time will also be set to the current time, and the time zone
     * will be set the the system's default time zone.
     * </p>
     */
    public CronTrigger(String name, String group, String cronExpression)
            throws ParseException {
        super(name, group);

        setCronExpression(cronExpression);

        setStartTime(new Date());
        setTimeZone(TimeZone.getDefault());
    }

    /**
     * <p>
     * Create a <code>CronTrigger</code> with the given name and group, and
     * associated with the identified <code>{@link org.quartz.JobDetail}</code>.
     * </p>
     * 
     * <p>
     * The start-time will also be set to the current time, and the time zone
     * will be set the the system's default time zone.
     * </p>
     */
    public CronTrigger(String name, String group, String jobName,
            String jobGroup) {
        super(name, group, jobName, jobGroup);
        setStartTime(new Date());
        setTimeZone(TimeZone.getDefault());
    }

    /**
     * <p>
     * Create a <code>CronTrigger</code> with the given name and group,
     * associated with the identified <code>{@link org.quartz.JobDetail}</code>,
     * and with the given "cron" expression.
     * </p>
     * 
     * <p>
     * The start-time will also be set to the current time, and the time zone
     * will be set the the system's default time zone.
     * </p>
     */
    public CronTrigger(String name, String group, String jobName,
            String jobGroup, String cronExpression) throws ParseException {
        this(name, group, jobName, jobGroup, null, null, cronExpression,
                TimeZone.getDefault());
    }

    /**
     * <p>
     * Create a <code>CronTrigger</code> with the given name and group,
     * associated with the identified <code>{@link org.quartz.JobDetail}</code>,
     * and with the given "cron" expression resolved with respect to the <code>TimeZone</code>.