/**
     * 比较第一个日期是否大于第二个日期
     * @param firstDate 第一个日期
     * @param secondDate 第二个日期
     * @return true-大于;false-不大于
     */
    public static boolean localDateIsBefore(LocalDateTime  firstDate, LocalDateTime  secondDate) {
        return firstDate.isBefore(secondDate);
    }

  /**
     * 比较第一个日期是否小于第二个日期
     * @param firstDate 第一个日期
     * @param secondDate 第二个日期
     * @return true-小于;false-大于
     */
    public static boolean localDateIsAfter(LocalDateTime  firstDate, LocalDateTime  secondDate) {
        return firstDate.isAfter(secondDate);
    }
   /**
     * 得到本周周一日期
     * @return
     */
    public static String getWeekMonday(){
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        Calendar cal=new GregorianCalendar();
        cal.setFirstDayOfWeek(Calendar.MONDAY);
        cal.setTime(new Date());
        cal.set(Calendar.DAY_OF_WEEK, cal.getFirstDayOfWeek());
        Date first=cal.getTime();
        return sdf.format(first);
    }
    /**
     * 得到本周周五日期
     * @return
     */
    public   String getWeekFriday(){
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        Calendar cal=new GregorianCalendar();
        cal.setFirstDayOfWeek(Calendar.MONDAY);
        cal.set(Calendar.DAY_OF_WEEK, cal.getFirstDayOfWeek() + 4);
        Date last=cal.getTime();
        return sdf.format(last);
    }


    /**
     * 得到本周周日
     *
     * @return yyyy-MM-dd
     */
    public static String getSundayOfThisWeek() {
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        Calendar c = Calendar.getInstance();
        int day_of_week = c.get(Calendar.DAY_OF_WEEK) - 1;
        if (day_of_week == 0)
            day_of_week = 7;
        c.add(Calendar.DATE, -day_of_week + 7);
        return sdf.format(c.getTime());
    }


    /**
     * 获取上周五时间
     */
    public   Date lastFirday() {
        //作用防止周日得到本周日期
        Calendar calendar = Calendar.getInstance();
        while (calendar.get(Calendar.DAY_OF_WEEK) != Calendar.MONDAY) {
            calendar.add(Calendar.DAY_OF_WEEK, -1);
        }
        int dayOfWeek = calendar.get(Calendar.DAY_OF_WEEK) - 1;
        int offset = 7 - dayOfWeek;
        calendar.add(Calendar.DATE, offset - 9);
        return DateUtil.getFirstDayOfWeek(calendar.getTime(), 6);//这是从上周日开始数的到本周五为6
    }
    
    

# java