{% code %} package _9time;
import java.text.; import java.time.; import java.time.format.; import java.time.temporal.TemporalAdjusters; import java.util.;
public class Main { static String timestampToString(long epochMilli, Locale lo, String zoneId) { Instant ins = Instant.ofEpochMilli(epochMilli); DateTimeFormatter f = DateTimeFormatter.ofLocalizedDateTime(FormatStyle.MEDIUM, FormatStyle.SHORT); return f.withLocale(lo).format(ZonedDateTime.ofInstant(ins, ZoneId.of(zoneId))); } public static void main(String[] args) { //Date int n = 123400; // 123400 System.out.println(n); // 1e208 System.out.println(Integer.toHexString(n)); // $123,400.00 System.out.println(NumberFormat.getCurrencyInstance(Locale.US).format(n));
// 获取当前时间:
Date date = new Date();
System.out.println(date.getYear() + 1900); // 必须加上1900
System.out.println(date.getMonth() + 1); // 0~11，必须加上1
System.out.println(date.getDate()); // 1~31，不能加1
// 转换为String:
System.out.println(date.toString());
// 转换为GMT时区:
System.out.println(date.toGMTString());
// 转换为本地时区:
System.out.println(date.toLocaleString());
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.println(sdf.format(date));
SimpleDateFormat sdf1 = new SimpleDateFormat("E MMM dd, yyyy");
System.out.println(sdf1.format(date));
//Calendar
// 获取当前时间:
Calendar c = Calendar.getInstance();
int y = c.get(Calendar.YEAR);
int m = 1 + c.get(Calendar.MONTH);
int d = c.get(Calendar.DAY_OF_MONTH);
int w = c.get(Calendar.DAY_OF_WEEK);
int hh = c.get(Calendar.HOUR_OF_DAY);
int mm = c.get(Calendar.MINUTE);
int ss = c.get(Calendar.SECOND);
int ms = c.get(Calendar.MILLISECOND);
System.out.println(y + "-" + m + "-" + d + " " + w + " " + hh + ":" + mm + ":" + ss + "." + ms);
// 清除所有:
c.clear();
// 设置2019年:
c.set(Calendar.YEAR, 2019);
// 设置9月:注意8表示9月:
c.set(Calendar.MONTH, 8);
// 设置2日:
c.set(Calendar.DATE, 2);
// 设置时间:
c.set(Calendar.HOUR_OF_DAY, 21);
c.set(Calendar.MINUTE, 22);
c.set(Calendar.SECOND, 23);
System.out.println(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(c.getTime()));
// 2019-09-02 21:22:23
//TimeZone
TimeZone tzDefault = TimeZone.getDefault(); // 当前时区
TimeZone tzGMT9 = TimeZone.getTimeZone("GMT+09:00"); // GMT+9:00时区
TimeZone tzNY = TimeZone.getTimeZone("America/New_York"); // 纽约时区
System.out.println(tzDefault.getID()); // Asia/Shanghai
System.out.println(tzGMT9.getID()); // GMT+09:00
System.out.println(tzNY.getID()); // America/New_York
System.out.println(TimeZone.getAvailableIDs().toString());
//北京时间转为纽约时间
// 清除所有:
c.clear();
// 设置为北京时区:
c.setTimeZone(TimeZone.getTimeZone("Asia/Shanghai"));
// 设置年月日时分秒:
c.set(2019, 10 /* 11月 */, 20, 8, 15, 0);
// 显示时间:
SimpleDateFormat sdf2 = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
sdf2.setTimeZone(TimeZone.getTimeZone("America/New_York"));
System.out.println(sdf2.format(c.getTime()));
// 2019-11-19 19:15:00
//时间加减
// 清除所有:
c.clear();
// 设置年月日时分秒:
c.set(2019, 10 /* 11月 */, 20, 8, 15, 0);
// 加5天并减去2小时:
c.add(Calendar.DAY_OF_MONTH, 5);
c.add(Calendar.HOUR_OF_DAY, -2);
// 显示时间:
SimpleDateFormat sdf3 = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Date d3 = c.getTime();
System.out.println(sdf3.format(d3));
// 2019-11-25 6:15:00
//LocalDateTime
LocalDate d4 = LocalDate.now(); // 当前日期
LocalTime t4 = LocalTime.now(); // 当前时间
LocalDateTime dt4 = LocalDateTime.now(); // 当前日期和时间
System.out.println(d4); // 严格按照ISO 8601格式打印
System.out.println(t4); // 严格按照ISO 8601格式打印
System.out.println(dt4); // 严格按照ISO 8601格式打印
// 指定日期和时间:
LocalDate d5 = LocalDate.of(2019, 11, 30); // 2019-11-30, 注意11=11月
LocalTime t5 = LocalTime.of(15, 16, 17); // 15:16:17
LocalDateTime dt5 = LocalDateTime.of(2019, 11, 30, 15, 16, 17);
LocalDateTime dt55 = LocalDateTime.of(d5, t5);
System.out.println(d5);
System.out.println(t5);
System.out.println(dt5);
System.out.println(dt55);
LocalDateTime dt6 = LocalDateTime.parse("2019-11-19T15:16:17");
LocalDate d6 = LocalDate.parse("2019-11-19");
LocalTime t6 = LocalTime.parse("15:16:17");
System.out.println(dt6);
System.out.println(d6);
System.out.println(t6);
//DateTimeFormatter
// 自定义格式化:
DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyy/MM/dd HH:mm:ss");
System.out.println(dtf.format(LocalDateTime.now()));
// 用自定义格式解析:
LocalDateTime dt2 = LocalDateTime.parse("2019/11/30 15:16:17", dtf);
System.out.println(dt2);
//时间加减
LocalDateTime dt = LocalDateTime.of(2019, 10, 26, 20, 30, 59);
System.out.println(dt);
// 加5天减3小时:
LocalDateTime dt7 = dt.plusDays(5).minusHours(3);
System.out.println(dt7); // 2019-10-31T17:30:59
// 减1月:
LocalDateTime dt8 = dt7.minusMonths(1);
System.out.println(dt8); // 2019-09-30T17:30:59
//时间日期调整
LocalDateTime dt9 = LocalDateTime.of(2019, 10, 26, 20, 30, 59);
System.out.println(dt9);
// 日期变为31日:
LocalDateTime dt10 = dt9.withDayOfMonth(31);
System.out.println(dt10); // 2019-10-31T20:30:59
// 月份变为9:
LocalDateTime dt11 = dt10.withMonth(9);
System.out.println(dt11); // 2019-09-30T20:30:59
//with()
// 本月第一天0:00时刻:
LocalDateTime firstDay = LocalDate.now().withDayOfMonth(1).atStartOfDay();
System.out.println("本月第一天0:00时刻："+firstDay);
// 本月最后1天:
LocalDate lastDay = LocalDate.now().with(TemporalAdjusters.lastDayOfMonth());
System.out.println("本月最后1天："+lastDay);
// 下月第1天:
LocalDate nextMonthFirstDay = LocalDate.now().with(TemporalAdjusters.firstDayOfNextMonth());
System.out.println("下月第1天："+nextMonthFirstDay);
// 本月第1个周一:
LocalDate firstWeekday = LocalDate.now().with(TemporalAdjusters.firstInMonth(DayOfWeek.MONDAY));
System.out.println("本月第1个周一："+firstWeekday);
//判断时间先后
LocalDateTime now = LocalDateTime.now();
LocalDateTime target = LocalDateTime.of(2019, 11, 19, 8, 15, 0);
System.out.println(now.isBefore(target));
System.out.println(LocalDate.now().isBefore(LocalDate.of(2019, 11, 19)));
System.out.println(LocalTime.now().isAfter(LocalTime.parse("08:15:00")));
//Duration和Period 时间间隔，日期间隔
LocalDateTime start = LocalDateTime.of(2019, 11, 19, 8, 15, 0);
LocalDateTime end = LocalDateTime.of(2020, 1, 9, 19, 25, 30);
Duration d2 = Duration.between(start, end);
Duration d21 = Duration.ofHours(10); // 10 hours
Duration d22 = Duration.parse("P1DT2H3M"); // 1 day, 2 hours, 3 minutes
System.out.println(d2); // PT1235H10M30S
System.out.println(d21); // PT1235H10M30S
System.out.println(d22); // PT1235H10M30S
Period p = LocalDate.of(2019, 11, 19).until(LocalDate.of(2020, 1, 9));
System.out.println(p); // P1M21D
/**ZonedDateTime*/
ZonedDateTime zbj = ZonedDateTime.now(); // 默认时区
ZonedDateTime zny = ZonedDateTime.now(ZoneId.of("America/New_York")); // 用指定时区获取当前时间
System.out.println(zbj);
System.out.println(zny);
// 以中国时区获取当前时间:
ZonedDateTime zbj1 = ZonedDateTime.now(ZoneId.of("Asia/Shanghai"));
// 转换为纽约时间:
ZonedDateTime zny1 = zbj1.withZoneSameInstant(ZoneId.of("America/New_York"));
System.out.println(zbj1);
System.out.println(zny1);
ZonedDateTime zdt = ZonedDateTime.now();
LocalDateTime ldt = zdt.toLocalDateTime();
System.out.println(ldt);
/**DateTimeFormatter*/
ZonedDateTime zdt1 = ZonedDateTime.now();
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm ZZZZ");
System.out.println(formatter.format(zdt1));
DateTimeFormatter zhFormatter = DateTimeFormatter.ofPattern("yyyy MMM dd EE HH:mm", Locale.CHINA);
System.out.println(zhFormatter.format(zdt1));
DateTimeFormatter usFormatter = DateTimeFormatter.ofPattern("E, MMMM/dd/yyyy HH:mm", Locale.US);
System.out.println(usFormatter.format(zdt1));
LocalDateTime ldt1 = LocalDateTime.now();
System.out.println(DateTimeFormatter.ISO_DATE.format(ldt1));
System.out.println(DateTimeFormatter.ISO_DATE_TIME.format(ldt1));
//Instant 当前时间戳
Instant instant = Instant.now();
System.out.println(instant.getEpochSecond());
System.out.println(instant.toEpochMilli());
// 以指定时间戳创建Instant:
Instant ins = Instant.ofEpochSecond(1568568760);
ZonedDateTime zdt2 = ins.atZone(ZoneId.systemDefault());
System.out.println(zdt2); // 2019-09-16T01:32:40+08:00[Asia/Shanghai]
/**旧API转新API*/
// Date -> Instant:
Instant ins1 = new Date().toInstant();
// Calendar -> Instant -> ZonedDateTime:
Calendar calendar = Calendar.getInstance();
Instant ins2 = Calendar.getInstance().toInstant();
ZonedDateTime zdt3 = ins2.atZone(calendar.getTimeZone().toZoneId());
System.out.println(zdt3);
/**新API转旧API*/
// ZonedDateTime -> long:
ZonedDateTime zdt4 = ZonedDateTime.now();
long ts = zdt4.toEpochSecond() * 1000;
// long -> Date:
Date date1 = new Date(ts);
// long -> Calendar:
Calendar calendar1 = Calendar.getInstance();
calendar1.clear();
calendar1.setTimeZone(TimeZone.getTimeZone(zdt.getZone().getId()));
calendar1.setTimeInMillis(zdt4.toEpochSecond() * 1000);
//数据库时间
long ts1 = 1574208900000L;
System.out.println(timestampToString(ts1, Locale.CHINA, "Asia/Shanghai"));
System.out.println(timestampToString(ts1, Locale.US, "America/New_York"));
}
} {% endcode %}