現在の時間からの日数、時間、および分の計算

/**
 *                ,        .
 * @param calDate
 * @return
 */
public static String calculateTime(Date calDate){
    String tips = "";
    Date now = new Date();
    long l = calDate.getTime() - now.getTime();
    long days =  (l / (1000 * 60 * 60 * 24));
    if (days > 0){
        tips += days + " ";
    }
    long hours =  (l / (1000 * 60 * 60) - days*24);
    if (hours > 0 || (days > 0 && hours == 0)){
        tips += hours + "  ";
    }
    long mins =  (l / (1000 * 60)) - days*24*60 - hours*60;
    tips += mins + "  ";
    return tips;
}