crontab.java

jcrontab是一个定时器开源项目包 目前提供存取文件或数据库, 把执行结果寄发 email, 简单地设置在 Tomcat, Resin, Jetty 及 JBoss 之上, 更是可以取代 cron

/**
 *  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.*;
import java.util.*;
import org.jcrontab.data.*;
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: 1.56 $
 */

public class Crontab {
    
    private String version = "1.4";
    private HashMap tasks;
    private HashMap loadedClasses;
    private int iNextTaskID;
    private Properties prop = new Properties();
    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 {

	   this.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 {
		this.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 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
	 */
	private 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('\\','/');
         }
		 try {
		 File filez = new File(strFileName);
		 FileInputStream input = new FileInputStream(filez);
         prop.load(input);
		 input.close();
         
         for (Enumeration e = prop.propertyNames() ; e.hasMoreElements() ;) {
             String ss  = (String)e.nextElement();
             Log.debug(ss + " : " + prop.getProperty(ss));
         }
		 
         } catch (FileNotFoundException fnfe ) {
			if (isInternalConfig) {
 			org.jcrontab.data.DefaultFiles.createJcrontabDir();
			org.jcrontab.data.DefaultFiles.createCrontabFile();
			org.jcrontab.data.DefaultFiles.createPropertiesFile();
			loadConfig();
			} else {
				throw new FileNotFoundException("Unable to find: " + 
												strFileName);
			}
		 }
         prop.setProperty("version", version);
	}
	/**
	 *	This method gets the value of the given property
	 *	@param property
	 *  @return value
	 */
	public String getProperty(String property) {
		 return	prop.getProperty(property);
	}
	
	/**
	 *	This method sets the given property
	 *	@param property
	 *  @param value
	 */
	 public void setProperty(String property, String value) {
		 prop.setProperty(property, value);
	}
	
	/**
	 *	This method Stores in the properties File the given property and all the
	 *  "live" properties
	 *	@param property
	 *  @param value
	 */
	 public void storeProperty(String property, String value) {
		 prop.setProperty(property, value);
		 try {
			 File filez = new File(strFileName);
			 filez.delete();
			 OutputStream out = new FileOutputStream(filez);
			 prop.store(out, "Jcrontab Automatic Properties");
	     } catch (Exception e){
			Log.error(e.toString(), e);
		 }
	}
     /** 
      * This method says if today is a holiday or not
      * @return true if today is holiday false otherWise
      * @throws Exception
      */
    public boolean isHoliday() throws Exception {
        if (getProperty("org.jcrontab.data.holidaysource") == null 
            || getProperty("org.jcrontab.data.holidaysource") == "") 
        return false;
        Calendar today = Calendar.getInstance();
        HoliDay[] holidays = HoliDayFactory.getInstance().findAll();
        
        for (int i = 0; i< holidays.length; i++) {
            Calendar holiday = Calendar.getInstance();
            holiday.setTime(holidays[i].getDate());
             if (holiday.MONTH == today.MONTH &&
                 holiday.DAY_OF_MONTH == today.DAY_OF_MONTH) {
                     return true;
             }
        }
        return false;
    }
    /**
     * Creates and runs a new task
     * @param strClassName Name of the task
	 * @param strMethodName Name of the method that will be called
     * @param strExtraInfo Extra Information given to the task
     * @return The identifier of the new task created, or -1 if could not create
     * the new task (maximum number of tasks exceeded or another error)
     */
    public synchronized int newTask(String strClassName, 
    				   String strMethodName, String[] strExtraInfo) {
        CronTask newTask;
        Class cl;
        int iTaskID;

        // Do not run new tasks if it is uninitializing
        if(stoping) {
            return -1;
        }
		String params = "";
        try {
            iTaskID = iNextTaskID;

            cl = (Class)(loadedClasses.get(strClassName));
            
            // Creates the new task
            newTask = new CronTask();
            newTask.setParams(this, iTaskID, strClassName, strMethodName, 
								strExtraInfo);
			// Aded name to newTask to show a name instead of Threads whe 
            // logging
            // Thanks to Sander Verbruggen 
            int lastDot = strClassName.lastIndexOf(".");
            if (lastDot > 0 && lastDot < strClassName.length()) {
                String classOnlyName = strClassName.substring(lastDot + 1);
                newTask.setName(classOnlyName);
            }

            synchronized(tasks) {
                tasks.put(new Integer(iTaskID), 
                          new TaskTableEntry(strClassName, newTask));
            }
            // Starts the task execution
            newTask.setName("Crontask-"+iTaskID);
            newTask.start();

			if (strExtraInfo!=null && strExtraInfo.length > 0) { 
				for (int i = 0; i < strExtraInfo.length;i++) {
					params+=strExtraInfo[i] + " ";
				}
			}
			Log.info(strClassName + "#" + strMethodName + " " + params);
            // Increments the next task identifier
            iNextTaskID++;
            return iTaskID;

        } catch(Exception e) {
			Log.error("Smth was wrong with" + 
						strClassName + 
						"#" +
						strMethodName + 
						" " + 
						params, e);
        }
        return -1;
    }

    /**
     * Removes a task from the internal arrays of active tasks. This method
     * is called from method run() of CronTask when a task has finished.
     * @return true if the task was deleted correctly, false otherwise
     * @param iTaskID Identifier of the task to delete
     */
    public boolean deleteTask(int iTaskID) {
        synchronized(tasks) {
            if( tasks.remove(new Integer(iTaskID)) == null)
                return false;
            return true;
        }
    }

    /**
     * Returns an array with all active tasks
     * @return An array with all active tasks
     * NOTE: Does not returns the internal array because it is synchronized,
     * returns a copy of it.
     */
    public CronTask[] getAllTasks() {
        CronTask[] t;
        synchronized(tasks) {
            int i = 0;
            t = new CronTask[tasks.size()];
            Iterator iter = tasks.values().iterator();
            while(iter.hasNext()) {
                t[i] = ((TaskTableEntry)(iter.next())).task;
                i++;
            }
        }
        return t;
    }
    
    /** 
     * Internal class that represents an entry in the task table 
     */
    private class TaskTableEntry {
        String strClassName;
        CronTask task;

        /** Constructor of an entry of the task table
         * @param strClassName Name of the class of the task
         * @param task Reference to the task
         */        
        public TaskTableEntry(String strClassName,
                                 CronTask task) {
            this.strClassName = strClassName;
            this.task = task;
        }
    }
}