Java8 日期时间API

Posted 2021-03-01 coder-zyc

• LocalDate

• LocalTime

• LocalDateTime

/**
  * LocalDateTime相较于LocalDate，LocalTime，使用频率要高
  */
public void LocalDateTest() {
    //now():获取当前的日期，时间，日期加时间
    LocalDate localDate = LocalDate.now();
    LocalTime localTime = LocalTime.now();
    LocalDateTime localDateTime = LocalDateTime.now();

    /**
         * 打印结果：
         * 2020-02-13
         * 10:25:54.516
         * 2020-02-13T10:25:54.516
         */
    System.out.println(localDate);
    System.out.println(localTime);
    System.out.println(localDateTime);

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

    //of():设置指定的年，月，日，时，分，秒，没有偏移量
    LocalDateTime localDateTime1 = LocalDateTime.of(2020, 2, 12, 16, 30, 30);
    /**
         * 打印结果如下:
         * 2020-02-12T16:30:30
         */
    System.out.println(localDateTime1);

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

    //getXxx():获取相关属性
    /**
         * 打印结果如下:
         * 44
         * 13
         * THURSDAY
         * FEBRUARY
         * 2
         * 39
         */
    System.out.println(localDateTime.getDayOfYear());
    System.out.println(localDateTime.getDayOfMonth());
    System.out.println(localDateTime.getDayOfWeek());
    System.out.println(localDateTime.getMonth());
    System.out.println(localDate.getMonth().getValue());
    System.out.println(localDateTime.getMinute());

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


    //原始数据不可变性
    //withXxx():设置相关属性
    LocalDate localDate1 = localDate.withDayOfMonth(22);
    System.out.println(localDate);
    System.out.println(localDate1);

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

    LocalDateTime localDateTime2 = localDateTime.withHour(4);
    System.out.println("localDateTime:" + localDateTime);
    System.out.println("localDateTime2:" + localDateTime2);

    //plusXxx:加操作
    LocalDateTime localDateTime3 = localDateTime.plusMonths(3);
    System.out.println("localDateTime:" + localDateTime);
    System.out.println("localDateTime3:" + localDateTime3);
    System.out.println("----------");

    //minusXxx:减操作
    LocalDateTime localDateTime4 = localDateTime.minusMonths(3);
    System.out.println("localDateTime:" + localDateTime);
    System.out.println("localDateTime4:" + localDateTime4);

}