hal/src/se/koc/hal/deamon/TimeUtility.java

package se.koc.hal.deamon;

import java.util.Calendar;

public class TimeUtility {
	public static final long SECOND_IN_MS = 1000;
	public static final long MINUTES_IN_MS = SECOND_IN_MS * 60;
	public static final long FIVE_MINUTES_IN_MS = MINUTES_IN_MS * 5;
    public static final long HOUR_IN_MS = MINUTES_IN_MS * 60;
    public static final long DAY_IN_MS = HOUR_IN_MS * 24;
    public static final long WEEK_IN_MS = DAY_IN_MS * 7;
    
    /**
     * Get the timstamp for the given timestamp floored with the period length. The result should point to the beginning of the timestamps period.
     * @param periodLengthInMs The periods length to floor the timestamp with
     * @param timestamp The timestamp to floor.
     * @return
     */
	public static long getTimestampPeriodStart(long periodLengthInMs, long timestamp){
		if(periodLengthInMs < DAY_IN_MS){	//simple math if the period is less than a day long
			return timestamp - (timestamp % periodLengthInMs);
		}else{
			Calendar cal = Calendar.getInstance();
			cal.setTimeInMillis(timestamp);
			boolean clear = false;
			int days = millisecondsToDays(periodLengthInMs);
			if(days > 0){
				int currentDay = cal.get(Calendar.DAY_OF_YEAR);
				cal.set(Calendar.DAY_OF_YEAR, (currentDay/days)*days);
				clear = true;
			}
			int hours = millisecondsToHourOfDay(periodLengthInMs);
			if(hours > 0){
				int currentHour = cal.get(Calendar.HOUR_OF_DAY);
				cal.set(Calendar.HOUR_OF_DAY, (currentHour/hours)*hours);
				clear = true;
			}else if(clear){
				cal.set(Calendar.HOUR_OF_DAY, 0);
			}
			int minutes = millisecondsToMinuteOfHour(periodLengthInMs);
			if(minutes > 0){
				int currentMinute = cal.get(Calendar.MINUTE);
				cal.set(Calendar.MINUTE, (currentMinute/minutes)*minutes);
				clear = true;
			}else if(clear){
				cal.set(Calendar.MINUTE, 0);
			}
			int seconds = millisecondsToSecondOfMinute(periodLengthInMs);
			if(seconds > 0){
				int currentSecond = cal.get(Calendar.SECOND);
				cal.set(Calendar.SECOND, (currentSecond/seconds)*seconds);
				clear = true;
			}else if(clear){
				cal.set(Calendar.SECOND, 0);
			}
			int milliseconds = millisecondsToMillisecondInSecond(periodLengthInMs);
			if(milliseconds > 0){
				int currentMillisecond = cal.get(Calendar.MILLISECOND);
				cal.set(Calendar.MILLISECOND, (currentMillisecond/milliseconds)*milliseconds);
			}else if(clear){
				cal.set(Calendar.MILLISECOND, 0);
			}
			return cal.getTimeInMillis();
		}
	}
	
	public static int millisecondsToMillisecondInSecond(long ms){
		return (int) (ms % SECOND_IN_MS);
	}
	
	public static int millisecondsToSecondOfMinute(long ms){
		return (int) ((ms % MINUTES_IN_MS) / SECOND_IN_MS);
	}
	
	public static int millisecondsToMinuteOfHour(long ms){
		return (int) ((ms % HOUR_IN_MS) / MINUTES_IN_MS);
	}
	
	public static int millisecondsToHourOfDay(long ms){
		return (int) ((ms % DAY_IN_MS) / HOUR_IN_MS);
	}
	
	public static int millisecondsToDays(long ms){
		return (int) (ms / DAY_IN_MS);
	}
	
	public static String msToString(long ms){
		String retval = "";
		int days = millisecondsToDays(ms);
		retval += days + "days+";
		int hours = millisecondsToHourOfDay(ms);
		retval += (hours<10?"0"+hours:hours);
		int minutes = millisecondsToMinuteOfHour(ms);
		retval += ":" + (minutes<10?"0"+minutes:minutes);
		int seconds = millisecondsToSecondOfMinute(ms);
		retval += ":" + (seconds<10?"0"+seconds:seconds);
		int milliseconds = millisecondsToMillisecondInSecond(ms);
		retval += "." + (milliseconds<100?"0"+(milliseconds<10?"0"+milliseconds:milliseconds):milliseconds);
		return retval;
	}
	
}