crontab.java

这是一个非常优秀的可以自己定义复杂任务调度配置的框架

/**
 *  This file is part of the jcrontab package
 *  Copyright (C) 2001-2003 Israel Olalla
 *
 *  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 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., 59 Temple Place, Suite 330, Boston,
 *  MA 02111-1307, USA
 *
 *  For questions, suggestions:
 *
 *  [e-mail]
 *
 */
package org.jcrontab;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.OutputStream;
import java.util.Calendar;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Properties;

import org.jcrontab.data.HoliDay;
import org.jcrontab.data.HoliDayFactory;
import org.jcrontab.log.Log;


/** 
 * Manages the creation and execution of all the scheduled tasks 
 * of jcrontab. This class is the core of the jcrontab
 * @author $Author: iolalla $
 * @version $Revision: 1.65 $
 */

public class Crontab {
    
    private String version = "2.0.RC1";
    private HashMap tasks;
    private HashMap loadedClasses;
    private int iNextTaskID;
    private Properties prop = null;
    private int iTimeTableGenerationFrec = 3;
    /** The Cron that controls the execution of the tasks */
    private Cron cron;
    private boolean stoping = false;
    private boolean daemon = true;
    
    private static String strFileName= System.getProperty("user.home") + 
										System.getProperty("file.separator") +
										".jcrontab" +
										System.getProperty("file.separator") +
										"jcrontab.properties";
	private boolean isInternalConfig = true;
    /** The only instance of this cache */
    private static Crontab singleton = null;
    
    /**
     * Crontab constructor
     * Change the default constructor to public if you need 
     * more than an instance running on the system
     */
    private Crontab() {
        tasks = new HashMap();
        loadedClasses = new HashMap();
        iNextTaskID = 1;
    }
    /**
     *  Returns the only instance of this class
     *  we've choosen a singleton pattern to avoid launch different Crontab
     *  If you need diferent crontab classes to be launched only should 
     *  Change the private constructor to public.
     *  @return singleton the only instance of this class
     */
    public static synchronized Crontab getInstance(){
			if (singleton == null){
				singleton = new Crontab();
			}
			return singleton;
    }
    
    /** 
     * Initializes the crontab, reading task table from configuration 
     * file
     * table
     * @throws Exception
     */    
    public void init() throws Exception {
       // Properties prop = new Properties
        // Creates the thread Cron, wich generates the engine events
		loadConfig();
        cron = new Cron(this, iTimeTableGenerationFrec);
        cron.setName("Cron");
        cron.setDaemon(daemon);
        cron.start();
        stoping = false;
    }
    
    /** 
     * Initializes the crontab, reading task table from configuration 
     * file
     * @param strFileName Name of the tasks configuration file
     * table
     * @throws Exception
     */    
    public void init(String strFileName)
                    throws Exception {

	   Crontab.strFileName = strFileName;
				loadConfig();
	   String refreshFrequency = 
					getProperty("org.jcrontab.Crontab.refreshFrequency");
		if (refreshFrequency != null) {
			this.iTimeTableGenerationFrec = Integer.parseInt(refreshFrequency);
		}
        // Creates the thread Cron, wich generates the engine events         
        cron = new Cron(this, iTimeTableGenerationFrec);
		isInternalConfig = true;
        cron.setName("Cron");
        cron.setDaemon(daemon);
        cron.start();
        stoping = false;
    }
					
    /**
     * Used by the loadCrontabServlet to start Crontab with the configuration 
     * passed in a Properties object.
     *
     * @param props a <code>Properties</code> object
     * @param iTimeTableGenerationFrec Frecuency of regeneration of the events
     * table
     * @throws Exception
     */
    public void init(Properties props) 
                    throws Exception {
		Crontab.strFileName = null;
		String refreshFrequency = 
					props.getProperty("org.jcrontab.Crontab.refreshFrequency");
		this.prop = props;
		
		if (refreshFrequency != null) {
		this.iTimeTableGenerationFrec = Integer.parseInt(refreshFrequency);
		}
        // Creates the thread Cron, wich generates the engine events         
        cron = new Cron(this, iTimeTableGenerationFrec);
        cron.setName("Cron");
        cron.setDaemon(daemon);
        cron.start();
        stoping = false;
    }
    /** 
     * UnInitializes the Crontab. Calls to the method stopInTheNextMinute() 
	 * of the Cron.
     * @param iSecondsToWait Number of seconds to wait for the tasks to end
     * their process before returning from this method
     */    
    public void uninit() {
            if (stoping) return;
            stoping = true;
            cron.stopInTheNextMinute();
    }
    /** 
     * UnInitializes the crontab. Calls to the method join() of each of
     * the tasks running.
     * @param iSecondsToWait Number of seconds to wait for the tasks to end
     * their process before returning from this method
     */    
    public void uninit(int iSecondsToWait) {
        if (stoping) return;
        try {
            // Updates uninitializing flag
            stoping = true;
            cron.stopInTheNextMinute();
            CronTask[] tasks = getAllTasks();

            for(int i=tasks.length-1; i>=0; i--) {
                tasks[i].join(iSecondsToWait);
            }

        } catch(InterruptedException e) {
	    Log.error(e.toString(), e);
        }
    }
    /**
     * This method is here to make easier to access all the properties names
     * @return String[] all the properties valid in the config file
     */
    public String[] getAllThePropertiesNames() {
        String[] list = {"org.jcrontab.config",
                        "org.jcrontab.data.file", 
                        "org.jcrontab.data.datasource",
                        "org.jcrontab.Crontab.refreshFrequency",
                        "org.xml.sax.driver",
                        "org.jcrontab.data.GenericSQLSource.driver",
                        "org.jcrontab.data.GenericSQLSource.url",
                        "org.jcrontab.data.GenericSQLSource.username",
                        "org.jcrontab.data.GenericSQLSource.password",
                        "org.jcrontab.data.GenericSQLSource.dbDataSource",
                        "org.jcrontab.sendMail.to",
                        "org.jcrontab.sendMail.from",
                        "org.jcrontab.sendMail.smtp.host",
                        "org.jcrontab.sendMail.smtp.user",
                        "org.jcrontab.sendMail.smtp.password",
                        "org.jcrontab.log.Logger",
                        "org.jcrontab.log.log4J.Properties",
                        "org.jcrontab.data.FileOpener",
                        "org.jcrontab.data.holidaysource",
                        "org.jcrontab.data.holidaysfilesource",
                        "org.jcrontab.data.dateFormat"};
         return list;
    }
    /**
     * This method sets the Cron to daemon or not
	 *	@param boolean daemon
	 *  @throws Exception
	 */
    public void setDaemon(boolean daemon) {
        this.daemon = daemon;
    }
	/**
	 *	This method loads the config for the whole Crontab.
	 *  If this method doesn't find the files creates itself them
	 *	@param property
	 *  @throws Exception
	 */
	public void loadConfig() throws Exception {
	     // Get the Params from the config File
         // Don't like those three lines. But are the only way i have to grant
         // It works in any O.S.
         if (strFileName.indexOf("\\") != -1) {
			strFileName= strFileName.replace('\\','/');
         }
         if (prop == null) prop = new Properties();