新时间与日期API
本地时间
类
-
LocalDate
-
LocalTIme
-
LocalDateTime
简介
-
人读的时间
-
提供以ISO-8601为标准的日期和时间
-
提供简单的日期或时间
-
并不包含当前的时间信息
-
也不包含与时区相关的信息
示例
public void test1() {
LocalDateTime localDateTime = LocalDateTime.now();
System.out.println(localDateTime);
// 2023-05-18T15:01:52.140
LocalDateTime localDateTime1 = LocalDateTime.of(2023, 5, 18, 14, 59, 10);
System.out.println(localDateTime1);
// 2023-05-18T14:59:10
LocalDateTime localDateTime2 = localDateTime.plusYears(2);
System.out.println(localDateTime2);
// 2025-05-18T15:01:52.140
LocalDateTime localDateTime3 = localDateTime.minusMinutes(2);
System.out.println(localDateTime3);
// 2023-05-18T14:59:52.140
System.out.println(localDateTime1.getYear() + " "
+ localDateTime1.getMonth() + " "
+ localDateTime1.getDayOfMonth() + " "
+ localDateTime1.getHour() + " "
+ localDateTime1.getMinute() + " "
+ localDateTime1.getSecond()
);
// 2023 MAY 18 14 59 10
}
时间戳
类
Instant
简介
-
计算机读的时间
-
以Unix元年（1970年1月1日 00：00：00）到某个时间之间的毫秒值
-
默认获取UTC的时间
示例
@Test
public void test2() {
Instant instant = Instant.now();
System.out.println(instant); // 2023-05-18T07:17:56.307Z
// 获取差8个时区的时间偏移量
OffsetDateTime odt = instant.atOffset(ZoneOffset.ofHours(8));
System.out.println(odt); // 2023-05-18T15:17:56.307+08:00
// 转成毫秒时间
System.out.println(instant.toEpochMilli()); // 1684394382019
// 基于元年做运算
Instant instant1 = Instant.ofEpochSecond(60);
System.out.println(instant1); // 1970-01-01T00:01:00Z
}
间隔
类
-
Duration
- 两个时间之间的间隔
-
Period
- 两个本地日期之间的间隔
示例
public void test3() {
Instant instant = Instant.now();
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
System.out.println("醒了");
}
Instant instant1 = Instant.now();
Duration duration = Duration.between(instant, instant1);
System.out.println(duration.toMillis()); // 1002
System.out.println("----------------------");
LocalDate localDate = LocalDate.of(2015, 1, 1);
LocalDate localDate1 = LocalDate.now();
Period period = Period.between(localDate, localDate1);
System.out.println(period); // P8Y4M17D
}
时间矫正器
类
-
TemporalAdjuster
-
时间矫正器
-
比如，将日期调整到下一个周日
-
-
TemporaAdiusters
- 通过静态方法提供了大量的常用TemporalAdjuster
示例
public void test5() {
LocalDateTime localDateTime = LocalDateTime.now();
System.out.println(localDateTime); // 2023-05-18T15:52:42.128
// 将日期改成这个月的第十天
LocalDateTime localDateTime1 = localDateTime.withDayOfMonth(10);
System.out.println(localDateTime1); // 2023-05-10T15:52:42.128
// 将时间调整到下个周五
LocalDateTime localDateTime2 = localDateTime.with(TemporalAdjusters.next(DayOfWeek.FRIDAY));
System.out.println(localDateTime2); // 2023-05-19T15:52:42.128
//自定义：下一个工作日
LocalDateTime localDateTime4 = localDateTime.with((l) -> {
LocalDateTime localDateTime3 = (LocalDateTime) l;
if (localDateTime3.getDayOfWeek() == DayOfWeek.SATURDAY
|| localDateTime3.getDayOfWeek() == DayOfWeek.FRIDAY) {
return localDateTime3.with(TemporalAdjusters.next(DayOfWeek.MONDAY));
} else {
return localDateTime3.plusDays(1);
}
});
System.out.println(localDateTime4); // 2023-05-19T15:52:42.128
}
时间格式化
类
DateTimeFormatter
示例
public void test6() {
DateTimeFormatter isoDate = DateTimeFormatter.ISO_DATE;
LocalDateTime localDateTime = LocalDateTime.now();
System.out.println(localDateTime); // 2023-05-18T16:04:52.139
String strDate = localDateTime.format(isoDate);
System.out.println(strDate); // 2023-05-18
// 自定义
DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd");
strDate = localDateTime.format(dateTimeFormatter);
System.out.println(strDate); // 2023-05-18
// 从字符串获取日期
LocalDate localDate = LocalDate.parse(strDate, dateTimeFormatter);
System.out.println(localDate); // 2023-05-18
}
时区
类
-
ZoneDate
-
ZoneTime
-
ZoneDateTime
示例
public void test8() {
// 获得上海的时间
LocalDateTime shanghai = LocalDateTime.now(ZoneId.of("Asia/Shanghai"));
System.out.println(shanghai); // 2023-05-18T16:14:02.221
// 带时区的时间
ZonedDateTime shanghaiWithZone = shanghai.atZone(ZoneId.of("Asia/Shanghai"));
System.out.println(shanghaiWithZone); // 2023-05-18T16:14:02.221+08:00[Asia/Shanghai]
}