Java8 时间类常用方法

//当前日期
LocalDate date = LocalDate.now();//2020-07-12

//年月日
int year = date.getYear();//2020
int month = date.getMonthValue();//7
int day = date.getDayOfMonth();//12

//指定日期
LocalDate newDate = LocalDate.of(2019, 1, 1);//2019-01-0.1

//日期计算
date.plus(1, ChronoUnit.DAYS);
date.minus(1,ChronoUnit.DAYS);

//当前时间
LocalTime time = LocalTime.now();//23:25:38.100

//时间计算
time.plus(1,ChronoUnit.HOURS);
time.minus(1,ChronoUnit.HOURS);

//当前时间戳
Instant instant = Instant.now();//2020-07-12T15:25:38.101Z

//当前日期时间
LocalDateTime now = LocalDateTime.now();//2020-07-12T23:25:38.114

//字符串转化为日期
String dateStr = "20200712";
LocalDate dateParse = LocalDate.parse(dateStr, DateTimeFormatter.BASIC_ISO_DATE);//2020-07-12

//日期比较
LocalDate today = LocalDate.now();
LocalDate tomorrow = today.plus(1,ChronoUnit.DAYS);
LocalDate yesterday = today.minus(1,ChronoUnit.DAYS);
System.out.println(today.isBefore(tomorrow));//true
System.out.println(today.isAfter(yesterday));//true

//日期转化为字符串
String dayStr = date.format(DateTimeFormatter.BASIC_ISO_DATE);

//按照指定格式格式化
DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
String dateString = "2020-07-12 22:17:09";

LocalDateTime dateParse2 = LocalDateTime.parse(dateString,dtf);//2020-07-12T22:17:09
String formatStr = now.format(dtf);//2020-07-12 23:25:38

//判断是不是闰年
date.isLeapYear();//true

//计算两个日期间的年数、月数、天数
LocalDate one = LocalDate.of(2019,1,1);
LocalDate two = LocalDate.now();
Period period = Period.between(one, two);
int years = period.getYears();//1年
int months = period.getMonths();//6个月
int days = period.getDays();//11天
//实际计算相隔天数
long result = two.toEpochDay()-one.toEpochDay();//558天

//时区设置
//2020-07-12T23:47:59.154+09:00[Asia/Tokyo]
ZonedDateTime dateAndTimeInTokyo = ZonedDateTime.of(now,ZoneId.of("Asia/Tokyo"));