java8 时间类型相关类

Dear 丶 2022-10-16 03:56 154阅读 0赞

# java8 时间类型相关类 #

//获取今天
            LocalDate today = LocalDate.now();
            System.out.println(today);
     
            //获取固定某一天
            LocalDate d1=  LocalDate.of(2020,1,2);
            System.out.println(d1);
     
            //获取固定某一天
            LocalDate d2 = LocalDate.parse("2020-11-11");
            System.out.println(d2);
     
            //获取某个月的第一天
            LocalDate d3 = LocalDate.now().with(TemporalAdjusters.firstDayOfMonth());
            System.out.println(d3);
     
            //某个月的第三天
            LocalDate d4 = LocalDate.now().withDayOfMonth(3);
            System.out.println(d4);
     
            //某个月的最后一天
            LocalDate d5 = today.with(TemporalAdjusters.lastDayOfMonth());
            System.out.println(d5);
     
            //给某个时间加两天
            LocalDate d6 = LocalDate.now().plusDays(2);
            System.out.println(d6);
     
            //取2020年10月底一个周三
            LocalDate d7 = LocalDate.parse("2020-10-01").with(TemporalAdjusters.firstInMonth(DayOfWeek.WEDNESDAY));
            System.out.println(d7);

# LocalTime 基本使用 指定时间，时分秒，获取时分秒 #

//时间类型带纳秒
            LocalTime t1 = LocalTime.now();
            System.out.println(t1);
            //时间类型不带纳秒
            LocalTime t2 = LocalTime.now().withNano(0);
            System.out.println(t2);
            //时间类型重写分钟
            LocalTime t4 = LocalTime.now().withMinute(20).withNano(0);
            System.out.println(t4);
            //字符串指定时间
            LocalTime t5 = LocalTime.parse("22:22:22");
            System.out.println(t5);
            //获取日期时间类型
            LocalDateTime dt = LocalDateTime.now();
            System.out.println(dt);

# LocalDateTime的基本使用 #

## 时间的加减，时间的时区转换，时间的format，时间的间隔计算 ##

//获取日期时间类型
            LocalDateTime dt = LocalDateTime.now();
            System.out.println(dt);
     
            //对时间进行时区转换
            String dt1 = LocalDateTime.now().toInstant(ZoneOffset.of("-5")).toString();
            System.out.println(dt1);
     
            //用百万毫秒进行时区转换，对世界就行格式化
            long time = LocalDateTime.now().toInstant(ZoneOffset.of("+8")).toEpochMilli();
            DateTimeFormatter df = DateTimeFormatter.ofPattern("YYYY-MM-dd HH:mm:ss:SSS");
            String dfd = df.format(LocalDateTime.ofInstant(Instant.ofEpochMilli(time), ZoneId.of("Asia/Shanghai")));
            System.out.println(dfd);
     
            //格式化时间的不同方式
            DateTimeFormatter df1 = DateTimeFormatter.ofPattern("yyyy年MM月dd日");
            String d1 = LocalDateTime.now().format(df1);
            String d2 = df1.format(LocalDateTime.now());
            System.out.println(d1);
            System.out.println(d2);
     
            //计算时间间隔
            Instant ins = Instant.now();
            Instant ins1 = Instant.now().plusSeconds(10);
            Long duration = Duration.between(ins,ins1).toMillis();
            System.out.println(duration);
     
            //计算日期间隔
            LocalDate localDate = LocalDate.of(2018,12,8);
            LocalDate localDate1 = LocalDate.now();
            Period p = Period.between(localDate,localDate1);
            System.out.println("相隔"+ p.getYears() + "年" +p.getMonths() + "月"+p.getDays()+"天");
     
            //获取下个周六
            LocalDateTime localDateTime = LocalDateTime.now();
            localDateTime.with(TemporalAdjusters.next(DayOfWeek.SATURDAY));