关于一些日期工具方法

1、常量

　　主要是一些常用格式还有数据。

 　　public static final long SECOND = 1000L;
    public static final long MINUTE = 60000L;
    public static final long HOUR = 3600000L;
    public static final long DAY = 86400000L;
    public static final long WEEK = 604800000L;
    public static final String HOUR_FORMAT = "HH";
    public static final String DAY_BEGIN_STRING_HHMMSS = " 00:00:00";
    public static final String DAY_END_STRING_HHMMSS = " 23:59:59";
    public static final String TIME_FORMAT_FULL = "yyyy-MM-dd HH:mm:ss";
    public static final String TIME_FORMAT_FULL_SIMP = "yyyyMMddHHmmss";
    public static final String TIME_FORMAT_YMD = "yyyy-MM-dd";
    public static final String TIME_FORMAT_YMD_SIMP = "yyyyMMdd";

2、常用方法

1)获取当前时间戳

public static Timestamp getCurrentTimestamp() {
   return new Timestamp(System.currentTimeMillis());
}

2)获取指定时间的时间戳

public static Timestamp getTimestamp(Date date) {
   return new Timestamp(date.getTime());
}

3)日期格式转为字符串

public static String dateFormat(Date date, String formatStr) {
     if(date == null){
            return null;
    }  
    DateFormat simpleDateFormat = new SimpleDateFormat(formatStr);
    return simpleDateFormat.format(date);
}
    

4)字符串转日期格式

public static Date parse(String str, String format) {
        SimpleDateFormat sdf = new SimpleDateFormat(format);
        try {
            return sdf.parse(str);
        } catch (ParseException var4) {
            var4.printStackTrace();
            return null;
        }
 }

 

5）获取当前年、月、日、周几

/**
     * 获取指定日期当前年份
     * @param date
     * @return
     */
    public static int getYear(Date date) {
        Calendar calendar = Calendar.getInstance();
　　  if(date != null){
           calendar.setTime(date);
        }
        return calendar.get(Calendar.YEAR);
    }

    /**
     * 获取指定日期当前月份
     * @param date
     * @return
     */
    public static int getMonth(Date date) {
        Calendar calendar = Calendar.getInstance();
       if(date != null){
           calendar.setTime(date);
        }
        return calendar.get(Calendar.MONTH) + 1;
    }

    /**
     * 获取指定日期当前号数
     * @param date
     * @return
     */
    public static int getDay(Date date){
        Calendar calendar = Calendar.getInstance();
        if(date != null){
           calendar.setTime(date);
        }
        return calendar.get(Calendar.DATE);
    }
    /**
     * 获取当前周几（0:周日 1：周一  2：周二  3：周三  4：周四  5：周五  6：周六 ）
     * @return
     */
    public static int getWeek(Date date){
        Calendar calendar = Calendar.getInstance();
        if(date != null){
           calendar.setTime(date);
        }
        return calendar.get(Calendar.DAY_OF_WEEK) - 1;
    } 

 

6）获取指定日期增加年、月、日、时、分、毫秒

基础方法

/**
     * 时间增加基础方法
     * @param date
     * @param calendarField
     * @param amount
     * @return
     */
    private static Date add(Date date, int calendarField, int amount) {
        Calendar c = Calendar.getInstance();
        c.setTime(date);
        c.add(calendarField, amount);
        return c.getTime();
    }

由基础方法扩展出来的方法

/**
     * 年份增加
     * @param date
     * @param amount
     * @return
     */
    public static Date addYears(Date date, int amount) {
        return add(date, Calendar.YEAR, amount);
    }

    /**
     * 月份增加
     * @param date
     * @param amount
     * @return
     */
    public static Date addMonths(Date date, int amount) {
        return add(date, Calendar.MONTH, amount);
    }

    /**
     * 周数增加
     * @param date
     * @param amount
     * @return
     */
    public static Date addWeeks(Date date, int amount) {
        return add(date, Calendar.WEEK_OF_YEAR, amount);
    }

    /**
     * 天数增加
     * @param date
     * @param amount
     * @return
     */
    public static Date addDays(Date date, int amount) {
        return add(date, Calendar.DATE, amount);
    }

    /**
     * 小时数增加
     * @param date
     * @param amount
     * @return
     */
    public static Date addHours(Date date, int amount) {
        return add(date, Calendar.HOUR_OF_DAY, amount);
    }

    /**
     * 分钟数增加
     * @param date
     * @param amount
     * @return
     */
    public static Date addMinutes(Date date, int amount) {
        return add(date, Calendar.MINUTE, amount);
    }

    /**
     * 秒钟数增加
     * @param date
     * @param amount
     * @return
     */
    public static Date addSeconds(Date date, int amount) {
        return add(date, Calendar.SECOND, amount);
    }

    /**
     * 毫秒数增加
     * @param date
     * @param amount
     * @return
     */
    public static Date addMilliseconds(Date date, int amount) {
        return add(date, Calendar.MILLISECOND, amount);
    }

 

7）设置指定时间的年、月、日、时、分、秒、毫秒

基础方法

/**
     * 时间数设置基础方法
     * @param date
     * @param calendarField
     * @param amount
     * @return
     */
    private static Date set(Date date, int calendarField, int amount) {
        Calendar c = Calendar.getInstance();
        c.setLenient(false);
        c.setTime(date);
        c.set(calendarField, amount);
        return c.getTime();
    }

由基础方法扩展的方法

    /**
     * 年份设置
     * @param date
     * @param amount
     * @return
     */
    public static Date setYears(Date date, int amount) {
        return set(date, Calendar.YEAR, amount);
    }

    /**
     * 月份设置
     * @param date
     * @param amount （不是实际月份数，0表示1月 1表示2月 .... 11表示12月）
     * @return
     */
    public static Date setMonths(Date date, int amount) {
        return set(date, Calendar.MONTH, amount);
    }

    /**
     * 天数设置
     * @param date
     * @param amount
     * @return
     */
    public static Date setDays(Date date, int amount) {
        return set(date, Calendar.DATE, amount);
    }

    /**
     * 小时数设置
     * @param date
     * @param amount
     * @return
     */
    public static Date setHours(Date date, int amount) {
        return set(date, Calendar.HOUR_OF_DAY, amount);
    }

    /**
     * 分钟数设置
     * @param date
     * @param amount
     * @return
     */
    public static Date setMinutes(Date date, int amount) {
        return set(date, Calendar.MINUTE, amount);
    }

    /**
     * 秒数设置
     * @param date
     * @param amount
     * @return
     */
    public static Date setSeconds(Date date, int amount) {
        return set(date, Calendar.SECOND, amount);
    }

    /**
     * 毫秒数设置
     * @param date
     * @param amount
     * @return
     */
    public static Date setMilliseconds(Date date, int amount) {
        return set(date, Calendar.MILLISECOND, amount);
    }

 

 

 

8）获取指定日期的开始时间、结束时间

public static Date getDayBegin(Date date) {
      if (CommonUtil.isNull(date)) {
          return null;
      } 
      SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");
      String dateStr = simpleDateFormat.format(date);
      return newDate(dateStr + " 00:00:00", "yyyy-MM-dd HH:mm:ss");
 }

public static Date getDayEnd(Date date) {
      if (CommonUtil.isNull(date)) {
         return null;
      } 
      SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");
      String dateStr = simpleDateFormat.format(date);
      return newDate(dateStr + " 23:59:59", "yyyy-MM-dd HH:mm:ss");
}

 

9）计算两个日期的各种时间差

/**
     * 两个日期相减得到的毫秒数
     * @param beginDate
     * @param endDate
     * @return
     */
    public static long dateDiff(Date beginDate, Date endDate) {
        long date1ms = beginDate.getTime();
        long date2ms = endDate.getTime();
        return date2ms - date1ms;
    }

    /**
     * 两个日期相减得到的天数
     * @param beginDate
     * @param endDate
     * @return
     */
    public static int getDiffDays(Date beginDate, Date endDate) {
        long days = dateDiff(beginDate, endDate)/DateUtil.DAY;
        return (int) days;
    }

    /**
     * 两个日期相减得到的小时数
     * @param beginDate
     * @param endDate
     * @return
     */
    public static int getDiffHours(Date beginDate, Date endDate) {
        long days = dateDiff(beginDate, endDate)/DateUtil.HOUR;
        return (int) days;
    }

至于大家可能会问，为什么没有年月这两个的，主要是每个月天数，每年天数不固定，要做具体需要。

 

10）各种常见的方法

/**
     * 获取昨天的开始时间
     * @return
     */
    public static Date getBeginDayOfYesterday() {
        Calendar cal = new GregorianCalendar();
        cal.setTime(getDayBegin());
        cal.add(DAY_OF_MONTH, -1);
        return cal.getTime();
    }

    /**
     * 获取昨天的结束时间
     * @return
     */
    public static Date getEndDayOfYesterDay() {
        Calendar cal = new GregorianCalendar();
        cal.setTime(getDayEnd());
        cal.add(DAY_OF_MONTH, -1);
        return cal.getTime();
    }

/**
     * 获取明天的开始时间
     * @return
     */
    public static Date getBeginDayOfTomorrow() {
        Calendar cal = new GregorianCalendar();
        cal.setTime(getDayBegin());
        cal.add(DAY_OF_MONTH, 1);
        return cal.getTime();
    }

    /**
     * 获取明天的结束时间
     * @return
     */
    public static Date getEndDayOfTomorrow() {
        Calendar cal = new GregorianCalendar();
        cal.setTime(getDayEnd());
        cal.add(DAY_OF_MONTH, 1);
        return cal.getTime();
    }

/**
     * 获取本周的开始时间
     * @return
     */
    @SuppressWarnings("unused")
    public static Date getBeginDayOfWeek() {
        Date date = new Date();
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);
        int dayofweek = cal.get(Calendar.DAY_OF_WEEK);
        if (dayofweek == 1) {
            dayofweek += 7;
        }
        cal.add(Calendar.DATE, 2 - dayofweek);
        return getDayBegin(cal.getTime());
    }

    /**
     * 获取本周的结束时间
     * @return
     */
    public static Date getEndDayOfWeek() {
        Calendar cal = Calendar.getInstance();
        cal.setTime(getBeginDayOfWeek());
        cal.add(Calendar.DAY_OF_WEEK, 6);
        return getDayEnd(cal.getTime());
    }

/**
     * 获取上周的开始时间
     * @return
     */
    @SuppressWarnings("unused")
    public static Date getBeginDayOfLastWeek() {
        return addWeeks(getBeginDayOfWeek(), -1);
    }

    /**
     * 获取上周的结束时间
     * @return
     */
    public static Date getEndDayOfLastWeek() {
        return addWeeks(getEndDayOfWeek(), -1);
    }

/**
     * 获取本月的开始时间
     * @return
     */
    public static Date getBeginDayOfMonth() {
        return getDayBegin(setDays(new Date(), 1));
    }

    /**
     * 获取本月的结束时间
     * @return
     */
    public static Date getEndDayOfMonth() {
        Calendar calendar = Calendar.getInstance();
        int last = calendar.getActualMaximum(Calendar.DATE);
        return getDayEnd(setDays(calendar.getTime(), last));
    }

/**
     * 获取指定日期当月开始时间
     * @return
     */
    public static Date getBeginDayOfMonth(Date date) {
        return getDayBegin(setDays(date, 1));
    }

    /**
     * 获取指定日期当月结束时间
     * @return
     */
    public static Date getEndDayOfMonth(Date date) {
        return getDayEnd(addMinutes(getBeginDayOfMonth(addMonths(date, 1)), -1));
    }

/**
     * 获取上月的开始时间
     * @return
     */
    public static Date getBeginDayOfLastMonth() {
        return addMonths(getBeginDayOfMonth(), -1);
    }

    /**
     * 获取上月的结束时间
     * @return
     */
    public static Date getEndDayOfLastMonth() {
        Date date = addDays(getBeginDayOfMonth(), -1);
        return getDayEnd(date);
    }

/**
     * 获取本年的开始时间
     * @return
     */
    public static Date getBeginDayOfYear() {
        Calendar cal = Calendar.getInstance();
        cal.set(Calendar.MONTH, Calendar.JANUARY);
        cal.set(Calendar.DATE, 1);
        return getDayBegin(cal.getTime());
    }

    /**
     * 获取本年的结束时间
     * @return
     */
    public static Date getEndDayOfYear() {
        Calendar cal = Calendar.getInstance();
        cal.set(Calendar.MONTH, Calendar.DECEMBER);
        cal.set(Calendar.DATE, 31);
        return getDayEnd(cal.getTime());
    }

/**
     * 获取指定日期的当年开始时间
     * @param date
     * @return
     */
    public static Date getBeginDayOfYear(Date date) {
        Calendar cal = new GregorianCalendar();
        cal.setTime(date);
        cal.set(Calendar.MONTH, Calendar.JANUARY);
        cal.set(Calendar.DATE, 1);
        return getDayBegin(cal.getTime());
    }

    /**
     * 获取指定日期的当年结束时间
     * @param date
     * @return
     */
    public static Date getEndDayOfYear(Date date) {
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);
        cal.set(Calendar.MONTH, Calendar.DECEMBER);
        cal.set(Calendar.DATE, 31);
        return getDayEnd(cal.getTime());
    }