日期格式归纳

日期格式归纳

1. Java常用日期格式归纳

           package com.Calder;
   
           import java.time.LocalDate;
           import java.time.LocalDateTime;
           import java.time.LocalTime;
           import java.time.format.DateTimeFormatter;
           import java.time.format.FormatStyle;
           import java.time.temporal.TemporalAccessor;
   
           public class Time
           {
               public static void main(String[] args) {
                   System.out.println(LocalTime.now());
                   System.out.println(LocalDateTime.now());
                   System.out.println(LocalDate.now());
                   LocalDateTime.of(2022,4,11,9,20,25,260);
                   LocalDateTime localDateTime = LocalDateTime.now();
                   //对当前的月份加4
                   LocalDateTime localDateTime1 = localDateTime.plusMonths(4);
                   System.out.println(localDateTime1);
                   //对当前月份减2
                   System.out.println(localDateTime.minusMonths(2));
                   //改当前月份为9
                   System.out.println(localDateTime.withMonth(9));
   
                   //localDateTime--String
                   //设置格式DateTimeFormatter.ISO_DATE_TIME;
                   DateTimeFormatter isoDateTime = DateTimeFormatter.ISO_DATE_TIME;
                   //实例化一个类LocalDateTime
                   LocalDateTime LocalDateTime = localDateTime.now();
                   String str = isoDateTime.format(localDateTime);
                   System.out.println(str);
                   //String ---localDateTime
                   TemporalAccessor parse = isoDateTime.parse(str);
                   System.out.println(parse);
                   //常用方法：
   
                   DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofLocalizedDate(FormatStyle.FULL);
                   //localDateTime--String
                   java.time.LocalDateTime now = localDateTime.now();
                   String format = dateTimeFormatter.format(now);
                   System.out.println(format);//2022年4月11日 星期一
   
                   DateTimeFormatter dateTimeFormatter1 = DateTimeFormatter.ofLocalizedDateTime(FormatStyle.LONG);
                   java.time.LocalDateTime now1 = localDateTime.now();
                   String format1 = dateTimeFormatter1.format(now1);
                   System.out.println(format1);//2022年4月11日 上午10时39分31秒
   
                   DateTimeFormatter dateTimeFormatter2 = DateTimeFormatter.ofLocalizedDateTime(FormatStyle.MEDIUM);
                   java.time.LocalDateTime now2 = localDateTime.now();
                   String format2 = dateTimeFormatter2.format(now2);
                   System.out.println(format2);//2022-4-11 10:39:31
                   DateTimeFormatter dateTimeFormatter3 = DateTimeFormatter.ofLocalizedDateTime(FormatStyle.SHORT);
                   java.time.LocalDateTime now3 = LocalDateTime.now();
                   System.out.println(dateTimeFormatter3.format(now3));//22-4-11 上午10:42
               }
   
           }