JDK8--操作解析格式化日期

   /**
     * 如何修改LocalDate对象，最简单的方式就是使用WithAttribute方法.
     * 使用通用的with方法也可以达到同样的目的
     */
    public static void  test01 () {
        LocalDate localDate = LocalDate.of(2019,4,30);
        System.out.println(localDate.toString());
        // localDate1时间是2021-4-30
        LocalDate localDate1 = localDate.withYear(2021);
        System.out.println(localDate1.toString());
        // localDate2时间是2021-3-30
        LocalDate localDate2 = localDate1.withMonth(3);
        System.out.println(localDate2.toString());

        //localDate3的日期是2021-09-30
        LocalDate localDate3 = localDate2.with(ChronoField.MONTH_OF_YEAR, 9);
        System.out.println(localDate3.toString());

    }

    /**
     * 通过增加减少日期来实现日期的变动
     */
    public static void test02 () {
        LocalDate localDate = LocalDate.of(2019,4,30);
        System.out.println(localDate.toString());
        // localhost1的日期是2021-04-30
        LocalDate localDate1 = localDate.plusYears(2);
        System.out.println(localDate1.toString());

        LocalDate localDate2 = localDate.plus(6, ChronoUnit.MONTHS);
        System.out.println(localDate2.toString());
        LocalDate localDate3 = localDate2.minus(6, ChronoUnit.MONTHS);
        System.out.println(localDate3.toString());
    }


    /**
     * 使用TemporalAdjuster
     */
    public static void  test03 () {
        LocalDate localDate = LocalDate.of(2019, 5, 6);
        System.out.println(localDate.toString());
        LocalDate localDate1 = localDate.with(TemporalAdjusters.nextOrSame(DayOfWeek.SUNDAY));
        System.out.println(localDate1.toString());
    }


    /**
     * format日期或者时间的用法
     */
    public static void  test04 () {
        LocalDate localDate = LocalDate.of(2019, 5, 6);
        System.out.println(localDate.format(DateTimeFormatter.ISO_LOCAL_DATE));
        LocalDateTime localDateTime = LocalDateTime.of(2019, 5, 6, 17, 55, 00);
        System.out.println(localDateTime.format(DateTimeFormatter.ISO_LOCAL_DATE_TIME));
        LocalDateTime localDateTime1 = LocalDateTime.parse("2019-05-06T17:55:00");
        System.out.println(localDateTime1);
    }