常用类-LocalDate、LocalTime、LocalDateTime

 @Test

    public void test1(){

        //实例化：now()获取当前日期、时间、日期 + 时间

        LocalDate localDate = LocalDate.now();

        LocalTime localTime = LocalTime.now();

        LocalDateTime localDateTime =  LocalDateTime.now();

        System.out.println(localDate);

        System.out.println(localTime);

        System.out.println(localDateTime);

        //of():设置指定的年、月、日、时、分、秒没有偏移量

        System.out.println("===================");

        LocalDateTime localDateTime1 = LocalDateTime.of(2020, 10, 23, 6, 23, 43);

        System.out.println(localDateTime1);

        //getXxx()

        System.out.println("===================");

        System.out.println(localDateTime.getDayOfMonth());//获取当前这一天是这一月的第几天

        System.out.println(localDateTime.getDayOfWeek());//获取当前这一天是这一周的星期几

        System.out.println(localDateTime.getMonth());//获取当前月的英文值

        System.out.println(localDateTime.getMonthValue());//获取当前月的数值

        System.out.println(localDateTime.getMinute());//获取当时时间的分钟数

        System.out.println("===================");

        //体现不可变性：修改日期的值不会对日期本身造成影响

        //withXxx():设置相关的属性

        LocalDateTime localDateTime2 = localDateTime.withDayOfMonth(22);

        System.out.println(localDateTime2);//修改当前日期数之后的日期

        System.out.println(localDateTime);//修改之前的日期

        System.out.println("===================");

        LocalDateTime localDateTime3 = localDateTime.withHour(14);

        System.out.println(localDateTime3);//修改当前的小时之后的值

        System.out.println(localDateTime);//修改之前的值

        System.out.println("===================");

        //

        LocalDateTime localDateTime4 = localDateTime.plusMonths(3);

        System.out.println(localDateTime4);//输出在当前月的基础上加上三个月之后的值

        System.out.println(localDateTime);

        LocalDateTime localDateTime5 = localDateTime.minusDays(6);

        System.out.println(localDateTime5);//输出在当前天数的基础上减去6天之后的值

        System.out.println(localDateTime);

    }