java8-时间对象

我不是女神ヾ 2021-11-29 11:16 195阅读 0赞

java8中推出类新的时间对象，以下做简要展示。

LocalTime

public static void main(String[] args) {
            LocalTime localTime = LocalTime.now();
            System.out.println(localTime.getHour());//当前几点
            System.out.println(localTime.getMinute());//当前分钟
            System.out.println(localTime.getSecond());//当前秒数
            System.out.println(localTime.toString());
            //todo 比较当前的hour和参数是否一致，一致返回当前对象，不一致根据参数时间创建一个新的LocalTime对象
            LocalTime localTime1 =  localTime.withHour(17);
            System.out.println(localTime1);
    
        }

LocalDate

//todo LocalDate 表示当前天数
        public static void main(String[] args) {
            LocalDate localDate = LocalDate.now();
            localDate = LocalDate.of(1994,12,13);
            System.out.println(localDate.getYear());//年
            System.out.println(localDate.getMonthValue());//月
            System.out.println(localDate.getDayOfMonth());//一个月中的第几天
            System.out.println(localDate.getDayOfYear());//一年中的第几天
            System.out.println(localDate.toString());//展示字符时间
    
        }

LocalDateTime

public static void main(String[] args) {
            LocalDateTime localDateTime = LocalDateTime.now();
            System.out.println("年："+localDateTime.getYear());
            System.out.println("月："+localDateTime.getMonthValue());
            System.out.println("日："+localDateTime.getDayOfMonth());
            System.out.println("时:"+localDateTime.getHour());
            System.out.println("分:"+localDateTime.getMinute());
            System.out.println("秒:"+localDateTime.getSecond());
            System.out.println(localDateTime.toString());
            System.out.println("一年中的第"+localDateTime.getDayOfYear()+"天");
            System.out.println("本周的第"+localDateTime.getDayOfWeek().getValue()+"天");
        }

DateTimeFormatter

public static void main(String[] args) {
            //todo  dateTimeFormatter的使用
            DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd:HH:mm:ss");
            LocalDateTime localDateTime = LocalDateTime.parse("2019-03-05:14:58:30",dateTimeFormatter);
            System.err.println(localDateTime.toString().replace("T"," "));
    
            ZonedDateTime dateTime = ZonedDateTime.now();
            DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
            String str =  dateTime.format(formatter);
            System.out.println(str);
        }