com.pureinfo.force.util.TimerUtil.java Source code

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Here is the source code for com.pureinfo.force.util.TimerUtil.java

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/**
 * PureInfo Force
 * @(#)TimerUtil.java   1.0 Dec 29, 2005
 * 
 * Copyright(c) 2004-2005, PureInfo Information Technology Corp. Ltd. 
 * All rights reserved, see the license file.
 * 
 * www.pureinfo.com.cn
 */

package com.pureinfo.force.util;

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.GregorianCalendar;
import java.util.Timer;
import java.util.TimerTask;

import org.apache.commons.lang.time.DateUtils;

import com.pureinfo.force.exception.PureException;
import com.pureinfo.force.exception.PureRuntimeException;

/**
 * <P>
 * Created on Dec 29, 2005 9:29:22 AM <BR>
 * Last modified on Dec 29, 2005
 * </P>
 * 
 * @author Freeman.Hu
 * @version 1.0, Dec 29, 2005
 * @since Force 1.0
 */
public final class TimerUtil {

    private TimerUtil() {
    }

    private static DateFormat TIME_FORMAT = new SimpleDateFormat("HH:mm");

    /**
     * @param _sTime
     *            must be "HH:mm" format
     */
    public static Timer scheduleEverydayAt(String _sTime, TimerTask _task) {
        return scheduleFrom(_sTime, DateUtils.MILLIS_PER_DAY, _task);
    }

    /**
     * @param _sTime
     *            must be "HH:mm" format
     */
    public static Timer scheduleFrom(String _sTime, long _lPeriod, TimerTask _task) {
        Calendar nowTime = new GregorianCalendar();
        Calendar firstTime = getTimeToday(nowTime, _sTime);
        firstTime.setTimeInMillis(getNext(firstTime.getTimeInMillis(), nowTime.getTimeInMillis(), _lPeriod));
        Timer timer = new Timer();
        timer.scheduleAtFixedRate(_task, firstTime.getTime(), _lPeriod);
        return timer;
    }

    private static Calendar getTimeToday(Calendar _today, String _sTime) {
        Calendar todayTime = new GregorianCalendar();
        try {
            todayTime.setTime(TIME_FORMAT.parse(_sTime));
        } catch (ParseException ex) {
            throw new PureRuntimeException(PureException.INVALID_REQUEST, "time must be HH:mm TIME_FORMAT", ex);
        }
        todayTime.set(Calendar.YEAR, _today.get(Calendar.YEAR));
        todayTime.set(Calendar.MONTH, _today.get(Calendar.MONTH));
        todayTime.set(Calendar.DAY_OF_MONTH, _today.get(Calendar.DAY_OF_MONTH));
        return todayTime;
    }

    static long getNext(long _lStart, long _lNow, long _lPeriod) {
        if (_lStart <= _lNow) {
            long lDiff = _lNow - _lStart;
            if (lDiff % _lPeriod == 0)
                return _lNow + _lPeriod;
            return _lStart + _lPeriod * (lDiff / _lPeriod + 1);
        }
        return _lStart;
    }
}