Java学习之LocalDateTime, LocalDate, LocalTime

//创建
LocalDateTime localDateTime = LocalDateTime.of(2026, 04, 14, 13, 20, 59);
LocalDate localDate = LocalDate.of(2026, 04, 14);
LocalTime localTime = LocalTime.of(13, 20, 59);

//三者之间转换
LocalDate flocalDate = localDateTime.toLocalDate();
LocalTime flocalTime = localDateTime.toLocalTime();
LocalDateTime flocalDateTime = LocalDateTime.of(flocalDate, flocalTime);

//Local时间 -> 字符串
String strLocalDateTime = localDateTime.format(DateTimeFormatter.ofPattern("yyyyMMddHHmmss"));
String strLocalDate = localDateTime.format(DateTimeFormatter.ofPattern("yyyyMMdd"));
String strLocalTime = localDateTime.format(DateTimeFormatter.ofPattern("HHmmss"));

//字符串 -> Local时间
String strDateTime = "2026/04/14 13:20:43";
LocalDateTime dateTime = LocalDateTime.parse(strDateTime,  DateTimeFormatter.ofPattern("yyyy/MM/dd HH:mm:ss"));
String strDate = "2026/04/14";
LocalDate date = LocalDate.parse(strDate,  DateTimeFormatter.ofPattern("yyyy/MM/dd"));
String strTime = "13:20:43";
LocalTime time = LocalTime.parse(strTime,  DateTimeFormatter.ofPattern("HH:mm:ss"));

//获得当前日期时间
LocalDateTime today = LocalDateTime.now();
LocalDate day = LocalDate.now();
LocalTime now = LocalTime.now();

//加1天
LocalDate nextDay = LocalDate.now().plusDays(1);
//减1天
LocalDate preDay = LocalDate.now().minusDays(1);

//判断日期是否在当前日期之后
nextDay.isAfter(LocalDate.now());
//判断日期是否在当前日期之前
preDay.isBefore(LocalDate.now());
//判断日期是否相等
nextDay.isEqual(preDay);
//判断两个日期相差几天
long days = ChronoUnit.DAYS.between(preDay, nextDay);
//判断两个日期相差几月
long months = ChronoUnit.MONTHS.between(preDay, nextDay);
//计算相差的年、月、日
Period period = Period.between(preDay, nextDay);