TimeUtils.java

package com.dahuo.learn.utils;

import java.util.Calendar;

/**
 * @author YanLu
 * @since 16/6/12
 */
public class TimeUtils {
    private final static long DAY = 3600 * 24 * 1000;

    // How long time is hours:minutes
    public static long getTime(int hours, int minutes){
        Calendar cal = Calendar.getInstance();
        long now = cal.getTimeInMillis();
        //set target time
        cal.set(Calendar.HOUR_OF_DAY, hours);
        cal.set(Calendar.MINUTE, minutes);
        cal.set(Calendar.SECOND, 0);
        cal.set(Calendar.MILLISECOND, 0);
        long targetTime = cal.getTimeInMillis();
        return (targetTime - now) > 0 ? (targetTime - now) : (targetTime - now) + DAY;
    }
    // How long time is hours:minutes
    public static long getBetweenNowToTime(int hours, int minutes){
        Calendar cal = Calendar.getInstance();
        long now = cal.getTimeInMillis();
        //set target time
        cal.set(Calendar.HOUR_OF_DAY, hours);
        cal.set(Calendar.MINUTE, minutes);
        cal.set(Calendar.SECOND, 0);
        cal.set(Calendar.MILLISECOND, 0);
        long targetTime = cal.getTimeInMillis();
        return Math.abs(targetTime - now);
    }

    // one day
    public static long getOneDayMillis(){
        return DAY;
    }
}