Several features of java1.8 (II.)

VII. Date API

Java 8 contains a new set of time-date APIs under package Java.time. The new date API is similar to the open source Joda-time library, but not exactly the same, the following example shows some of the most important parts of this new set of APIs:

1  Public classTest {2      Public Static voidMain (string[] args) {3         /**4 * (i) clock clocks5 * The Clock class provides a way to access the current date and time, clock is time zone sensitive and can be used to replace system.currenttimemillis () to obtain the current number of microseconds. 6 * A specific point in time can also be expressed using the instant class, and the instant class can also be used to create old Java.util.Date objects. 7          */8Clock Clock =Clock.systemdefaultzone ();9         LongMillis =Clock.millis ();TenSystem.out.println (millis+ ":" +System.currenttimemillis ()); OneInstant Instant =clock.instant (); ADate legacydate = Date.from (instant);//Legacy Java.util.Date - System.out.println (legacydate); -  the         /** - * (ii) timezones time zone - * The time zone is represented in the new API using ZoneID. The time zone can be easily obtained by using the static method of the.  - * Time zone defines the time difference to UTS, which is extremely important when converting between instant time objects to local date objects.  +          */ -System.out.println (Zoneid.getavailablezoneids ());//output all time zones +ZoneID zone1 = Zoneid.of ("Europe/berlin"); AZoneID zone2 = Zoneid.of ("Brazil/east"); atSystem.out.println (Zone1.getrules ());//output ZONERULES[CURRENTSTANDARDOFFSET=+01:00] -System.out.println (Zone2.getrules ());//output ZONERULES[CURRENTSTANDARDOFFSET=-03:00] -  -         /** - * (iii) LocalTime local time - * LocalTime defines a time with no time zone information, such as 10 o'clock in the evening, or 17:30:15.  in * The following example creates two local time using the time zone created by the preceding code. Then compare the time and calculate the two time difference in hours and minutes: -          */ toLocalTime Now1 =Localtime.now (zone1); +LocalTime Now2 =Localtime.now (zone2); -System.out.println (Now1.isbefore (now2));//false the         LongHoursbetween =ChronoUnit.HOURS.between (Now1, now2); *         LongMinutesbetween =ChronoUnit.MINUTES.between (Now1, now2); $System.out.println (Hoursbetween);//-2Panax NotoginsengSystem.out.println (Minutesbetween);//-179 -  the         /**LocalTime provides a variety of factory methods to simplify the creation of objects, including parsing time strings.  +          * A          */ theLocalTime late = Localtime.of (23, 59, 59); +System.out.println (late);//23:59:59 -DateTimeFormatter Germanformatter = $ DateTimeFormatter $ . Oflocalizedtime (Formatstyle.short) - . Withlocale (Locale.german); -LocalTime leettime = Localtime.parse ("13:37", germanformatter); theSystem.out.println (Leettime);//13:37 - Wuyi         /** the * (d) localdate Local dates - * Localdate represents an exact date, such as 2014-03-11. The object value is immutable and is basically consistent with localtime.  Wu * The following example shows how to add a day/month/year to a Date object. It is also important to note that these objects are immutable and that the operation returns always a new instance.  -          */ AboutLocaldate today =Localdate.now (); $Localdate tomorrow = Today.plus (1, chronounit.days); -Localdate yesterday = tomorrow.minusdays (2); - System.out.println (yesterday); -Localdate IndependenceDay = Localdate.of (Month.july, 4); ADayOfWeek DayOfWeek =Independenceday.getdayofweek (); +System.out.println (DayOfWeek);//FRIDAY the  -DateTimeFormatter GermanFormatter1 = $ DateTimeFormatter the . Oflocalizeddate (Formatstyle.medium) the . Withlocale (Locale.german); theLocaldate Xmas = localdate.parse ("24.12.2014", germanFormatter1); theSystem.out.println (xmas);//2014-12-24 -         //This is much more convenient than the date used before. in  the         /** the * (Fri) LocalDateTime local date and time About * LocalDateTime also represents the time and date, which is equivalent to merging the first two sections onto an object.  the * LocalDateTime and LocalTime and Localdate are immutable. LocalDateTime provides a number of ways to access specific fields.  the          */ theLocalDateTime sylvester = Localdatetime.of (Month.december, 31, 23, 59, 59); +DayOfWeek DayOfWeek1 =Sylvester.getdayofweek (); -System.out.println (DAYOFWEEK1);//Wednesday theMonth month =sylvester.getmonth ();BayiSYSTEM.OUT.PRINTLN (month);//December the         LongMinuteofday =Sylvester.getlong (chronofield.minute_of_day); theSystem.out.println (Minuteofday);//1439 -         /** - * As long as the time zone information is attached, it can be converted to a point-in-time instant object, instant Point-in-time objects can be easily converted to old-fashioned java.util.Date.  the          */ theInstant instant1 =Sylvester the . Atzone (Zoneid.systemdefault ()) the . Toinstant (); -Date legacyDate1 =Date.from (instant1); theSystem.out.println (LEGACYDATE1);//Wed Dec 23:59:59 CET the  the         /**94 * Format LocalDateTime and format time and date, in addition to using predefined formats, we can also define the format: the          */ theDateTimeFormatter formatter = the DateTimeFormatter98. Ofpattern ("MMM DD, yyyy-hh:mm"); AboutLocalDateTime parsed = Localdatetime.parse ("Nov 03, 2014-07:13", formatter); -String string =Formatter.format (parsed);101System.out.println (string);//2014-07:13, Geneva102 103         //Unlike Java.text.NumberFormat, the new version of DateTimeFormatter is immutable, so it is thread-safe. 104         //For more information about time-date formats:http://download.java.net/jdk8/docs/api/java/time/format/DateTimeFormatter.html the         //Java jdk1.8 The new offer of this time is still good at some point.106 107 108     }109  the 111  the}

It's okay. Use the new API or something, also good, learn more, think more

Several features of java1.8 (II.)