【Java技术指南】「Java8编程专题」让你真正会用对Java新版日期时间API编程指南

LocalDateTime now = LocalDateTime.now();
System.out.println(now);
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LocalDateTime now2= LocalDateTime.now(ZoneId.of("Europe/Paris"));
System.out.println(now2);
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Clock clock = Clock.system(ZoneId.of("Asia/Dhaka"));  
LocalDateTime now3= LocalDateTime.now(clock);  
System.out.println(now3);
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//2013-12-31 23:59  
LocalDateTime d1 = LocalDateTime.of(2013, 12, 31, 23, 59);  
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//年月日 时分秒 纳秒
LocalDateTime d2 = LocalDateTime.of(2013, 12, 31, 23, 59,59, 11);
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Instant instant = Instant.now();
LocalDateTime d3 = LocalDateTime.ofInstant(Instant.now(), ZoneId.systemDefault());
System.out.println(d3);
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LocalDateTime d4 = LocalDateTime.parse("2013-12-31T23:59");
System.out.println(d4);
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LocalDateTime d5 = LocalDateTime.parse("2013-12-31T23:59:59.999");
System.out.println(d5);
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DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy/MM/dd HH:mm:ss");
LocalDateTime d6 = LocalDateTime.parse("2013/12/31 23:59:59", formatter);  
System.out.println(formatter.format(d6));  
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System.out.println(d6.getYear());  //获取年份
System.out.println(d6.getMonth());  //获取月份
System.out.println(d6.getDayOfYear());  // 获取当年的第几天
System.out.println(d6.getDayOfMonth());//获取属于本月的第几天
System.out.println(d6.getDayOfWeek());// 获取相对于本周的日期
System.out.println(d6.getHour());// 小时
System.out.println(d6.getMinute());  //分钟
System.out.println(d6.getSecond());  // 秒数
System.out.println(d6.getNano());  //纳秒数
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LocalDateTime d7 = d6.minusDays(1);  
LocalDateTime d8 = d7.plus(1, IsoFields.QUARTER_YEARS);  
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Instant instant1 = Instant.now();
//精确到秒 得到相对于1970-01-01 00:00:00 UTC的一个时间
System.out.println(instant1.getEpochSecond());
//精确到毫秒
System.out.println(instant1.toEpochMilli()); 
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Clock clock1 = Clock.systemUTC(); 
//得到时钟的瞬时时间
Instant instant2 = Instant.now(clock1);
System.out.println(instant2.toEpochMilli());
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Clock clock2 = Clock.fixed(instant1, ZoneId.systemDefault()); 
Instant instant3 = Instant.now(clock2);//得到时钟的瞬时时间  
System.out.println(instant3.toEpochMilli());//与上面的 instant1代表的含义一样！
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Clock c1 = Clock.systemUTC(); 
System.out.println(c1.millis()); //每次调用将返回当前瞬时时间（UTC）  
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Clock c2 = Clock.systemDefaultZone(); 
Clock c31 = Clock.system(ZoneId.of("Europe/Paris")); //巴黎时区  
System.out.println(c31.millis()); //每次调用将返回当前瞬时时间（UTC）  
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Clock c32 = Clock.system(ZoneId.of("Asia/Shanghai"));//上海时区  
System.out.println(c32.millis());//每次调用将返回当前瞬时时间（UTC）  
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Clock c4 = Clock.fixed(Instant.now(), ZoneId.of("Asia/Shanghai"));//固定上海时区时钟  
System.out.println(c4.millis());  
Thread.sleep(1000);  
System.out.println(c4.millis()); //不变 即时钟时钟在那一个点不动  
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Clock c5 = Clock.offset(c1, Duration.ofSeconds(2)); //相对于系统默认时钟两秒的时钟  
System.out.println(c1.millis());  
System.out.println(c5.millis());  
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ZonedDateTime now = ZonedDateTime.now();
System.out.println(now);
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ZonedDateTime now2= ZonedDateTime.now(ZoneId.of("Europe/Paris"));  
System.out.println(now2);
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ZonedDateTime z1 = ZonedDateTime.parse("2013-12-31T23:59:59Z[Europe/Paris]");
System.out.println(z1);
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Duration d1 = Duration.between(Instant.ofEpochMilli(System.currentTimeMillis() - 12323123), Instant.now());
//得到相应的时差
System.out.println(d1.toDays());  
System.out.println(d1.toHours());  
System.out.println(d1.toMinutes());  
System.out.println(d1.toMillis());  
System.out.println(d1.toNanos());  
//1天时差 类似的还有如ofHours()  
Duration d2 = Duration.ofDays(1);  
System.out.println(d2.ofHours());
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//提供对java.util.Calendar的替换，提供对年历系统的支持  
Chronology c  = HijrahChronology.INSTANCE; 
ChronoLocalDateTime d = c.localDateTime(LocalDateTime.now());  
System.out.println(d);  
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Year year = Year.now();  
YearMonth yearMonth = YearMonth.now();
MonthDay monthDay = MonthDay.now();
System.out.println(year);//年  
System.out.println(yearMonth); //年-月  
System.out.println(monthDay); // 月-日  
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Period period1 = Period.ofDays(10);
System.out.println(period1);
Period period2 = Period.of(3, 5, 0);
System.out.println(period2);
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