接下来看一下工具类的操作：

        LocalDate today = LocalDate.now();
        System.out.println(today.getYear()+"年是闰年吗？ "+today.isLeapYear());
        System.out.println(today.isBefore(LocalDate.of(2015,1,1)));
        System.out.println(today.atTime(LocalTime.now()));

        System.out.println("10天后 "+today.plusDays(10));
        System.out.println("3周后 "+today.plusWeeks(3));
        System.out.println("20个月后 "+today.plusMonths(20));

        System.out.println("10天前 "+today.minusDays(10));
        System.out.println("3周前 "+today.minusWeeks(3));
        System.out.println("20月前 "+today.minusMonths(20));

        System.out.println("月初是"+today.with(TemporalAdjusters.firstDayOfMonth()));
        LocalDate lastDayOfYear = today.with(TemporalAdjusters.lastDayOfYear());
        System.out.println("年末是"+lastDayOfYear);

        Period period = today.until(lastDayOfYear);
        System.out.println("到年底是 "+period);
        System.out.println("还剩几个月 "+period.getMonths());