public static void main(String[] args) {
// Current Date
LocalDateTime today = LocalDateTime.now();
System.out.println("Current DateTime=" + today);
// Current Date using LocalDate and LocalTime
today = LocalDateTime.of(LocalDate.now(), LocalTime.now());
System.out.println("Current DateTime=" + today);
// Creating LocalDateTime by providing input arguments
LocalDateTime specificDate = LocalDateTime.of(2014, Month.JANUARY, 1, 10, 10, 30);
System.out.println("Specific Date=" + specificDate);
// Try creating date by providing invalid inputs
// LocalDateTime feb29_2014 = LocalDateTime.of(2014, Month.FEBRUARY, 28,
// 25,1,1);
// Exception in thread "main" java.time.DateTimeException:
// Invalid value for HourOfDay (valid values 0 - 23): 25
// Current date in "Asia/Kolkata", you can get it from ZoneId javadoc
LocalDateTime todayKolkata = LocalDateTime.now(ZoneId.of("Asia/Kolkata"));
System.out.println("Current Date in IST=" + todayKolkata);
// java.time.zone.ZoneRulesException: Unknown time-zone ID: IST
// LocalDateTime todayIST = LocalDateTime.now(ZoneId.of("IST"));
// Getting date from the base date i.e 01/01/1970
LocalDateTime dateFromBase = LocalDateTime.ofEpochSecond(10000, 0, ZoneOffset.UTC);
System.out.println("10000th second time from 01/01/1970= " + dateFromBase);
}
@Test
public void testLocalDateTime() {
System.out.println(LocalDateTime.now());
System.out.println(LocalDateTime.of(1994, Month.MAY, 15, 11, 30));
System.out.println(LocalDateTime.ofInstant(Instant.now(), ZoneId.systemDefault()));
System.out.println(LocalDateTime.ofEpochSecond(1450749600, 0, ZoneOffset.ofHours(8)));
System.out.printf("6 months from now: %s%n", LocalDateTime.now().plusMonths(6));
System.out.printf("6 days ago: %s%n", LocalDateTime.now().minusDays(6));
System.out.println(DateTimeFormatter.ISO_DATE_TIME.format(LocalDateTime.now()));
System.out.println(DateTimeFormatter.ofPattern("MM-dd HH:mm").format(LocalDateTime.now()));
}
public static void main(String[] args) throws Throwable {
int N = 10000;
long t1970 = new java.util.Date(70, 0, 01).getTime();
Random r = new Random();
for (int i = 0; i < N; i++) {
int days = r.nextInt(50) * 365 + r.nextInt(365);
long secs = t1970 + days * 86400 + r.nextInt(86400);
int nanos = r.nextInt(NANOS_PER_SECOND);
int nanos_ms = nanos / 1000000 * 1000000; // millis precision
long millis = secs * 1000 + r.nextInt(1000);
LocalDateTime ldt = LocalDateTime.ofEpochSecond(secs, nanos, ZoneOffset.UTC);
LocalDateTime ldt_ms = LocalDateTime.ofEpochSecond(secs, nanos_ms, ZoneOffset.UTC);
Instant inst = Instant.ofEpochSecond(secs, nanos);
Instant inst_ms = Instant.ofEpochSecond(secs, nanos_ms);
///////////// java.util.Date /////////////////////////
Date jud = new java.util.Date(millis);
Instant inst0 = jud.toInstant();
if (jud.getTime() != inst0.toEpochMilli() || !jud.equals(Date.from(inst0))) {
System.out.printf("ms: %16d ns: %10d ldt:[%s]%n", millis, nanos, ldt);
throw new RuntimeException("FAILED: j.u.d -> instant -> j.u.d");
}
// roundtrip only with millis precision
Date jud0 = Date.from(inst_ms);
if (jud0.getTime() != inst_ms.toEpochMilli() || !inst_ms.equals(jud0.toInstant())) {
System.out.printf("ms: %16d ns: %10d ldt:[%s]%n", millis, nanos, ldt);
throw new RuntimeException("FAILED: instant -> j.u.d -> instant");
}
//////////// java.util.GregorianCalendar /////////////
GregorianCalendar cal = new GregorianCalendar();
// non-roundtrip of tz name between j.u.tz and j.t.zid
cal.setTimeZone(TimeZone.getTimeZone(ZoneId.systemDefault()));
cal.setGregorianChange(new java.util.Date(Long.MIN_VALUE));
cal.setFirstDayOfWeek(Calendar.MONDAY);
cal.setMinimalDaysInFirstWeek(4);
cal.setTimeInMillis(millis);
ZonedDateTime zdt0 = cal.toZonedDateTime();
if (cal.getTimeInMillis() != zdt0.toInstant().toEpochMilli()
|| !cal.equals(GregorianCalendar.from(zdt0))) {
System.out.println("cal:" + cal);
System.out.println("zdt:" + zdt0);
System.out.println("calNew:" + GregorianCalendar.from(zdt0));
System.out.printf("ms: %16d ns: %10d ldt:[%s]%n", millis, nanos, ldt);
throw new RuntimeException("FAILED: gcal -> zdt -> gcal");
}
inst0 = cal.toInstant();
if (cal.getTimeInMillis() != inst0.toEpochMilli()) {
System.out.printf("ms: %16d ns: %10d ldt:[%s]%n", millis, nanos, ldt);
throw new RuntimeException("FAILED: gcal -> zdt");
}
ZonedDateTime zdt = ZonedDateTime.of(ldt_ms, ZoneId.systemDefault());
GregorianCalendar cal0 = GregorianCalendar.from(zdt);
if (zdt.toInstant().toEpochMilli() != cal0.getTimeInMillis()
|| !zdt.equals(GregorianCalendar.from(zdt).toZonedDateTime())) {
System.out.printf("ms: %16d ns: %10d ldt:[%s]%n", millis, nanos, ldt);
throw new RuntimeException("FAILED: zdt -> gcal -> zdt");
}
}
///////////// java.util.TimeZone /////////////////////////
for (String zidStr : TimeZone.getAvailableIDs()) {
// TBD: tzdt intergration
if (zidStr.startsWith("SystemV")
|| zidStr.contains("Riyadh8")
|| zidStr.equals("US/Pacific-New")
|| zidStr.equals("EST")
|| zidStr.equals("HST")
|| zidStr.equals("MST")) {
continue;
}
ZoneId zid = ZoneId.of(zidStr, ZoneId.SHORT_IDS);
if (!zid.equals(TimeZone.getTimeZone(zid).toZoneId())) {
throw new RuntimeException("FAILED: zid -> tz -> zid :" + zidStr);
}
TimeZone tz = TimeZone.getTimeZone(zidStr);
// no round-trip for alias and "GMT"
if (!tz.equals(TimeZone.getTimeZone(tz.toZoneId()))
&& !ZoneId.SHORT_IDS.containsKey(zidStr)
&& !zidStr.startsWith("GMT")) {
throw new RuntimeException("FAILED: tz -> zid -> tz :" + zidStr);
}
}
System.out.println("Passed!");
}