[英]Java time since the epoch
In Java, how can I print out the time since the epoch given in seconds and nanoseconds in the following format : 在Java中,如何以秒和纳秒的形式打印出自上述时间以来的时间,格式如下:
java.text.SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
My input is: 我的意见是:
long mnSeconds;
long mnNanoseconds;
Where the total of the two is the elapsed time since the epoch 1970-01-01 00:00:00.0
. 其中两者的总和是自
1970-01-01 00:00:00.0
纪元以来经过的时间。
Use this and divide by 1000 使用它并除以1000
long epoch = System.currentTimeMillis();
System.out.println("Epoch : " + (epoch / 1000));
You can do this 你可以这样做
public static String format(long mnSeconds, long mnNanoseconds) {
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.");
return sdf.format(new Date(mnSeconds*1000))
+ String.format("%09d", mnNanoseconds);
}
eg 例如
2012-08-08 19:52:21.123456789
if you don't really need any more than milliseconds you can do 如果你真的不需要超过毫秒,你可以做
public static String format(long mnSeconds, long mnNanoseconds) {
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
return sdf.format(new Date(mnSeconds*1000 + mnNanoseconds/1000000));
}
Instant // Represent a moment in UTC.
.ofEpochSecond( mnSeconds ) // Determine a moment from a count of whole seconds since the Unix epoch of the first moment of 1970 in UTC (1970-01-01T00:00Z).
.plusNanos( mnNanoseconds ) // Add on a fractional second as a count of nanoseconds. Returns another `Instant` object, per Immutable Objects pattern.
.toString() // Generate text representing this `Instant` object in standard ISO 8601 format.
.replace( "T" , " " ) // Replace the `T` in the middle with a SPACE.
.replace "Z" , "" ) // Remove the `Z` on the end (indicating UTC).
The java.time framework is built into Java 8 and later. java.time框架内置于Java 8及更高版本中。 These classes supplant the old troublesome date-time classes such as
java.util.Date
, .Calendar
, java.text.SimpleDateFormat
, java.sql.Date
, and more. 这些类取代了旧的麻烦的日期时间类,如
java.util.Date
, .Calendar
, java.text.SimpleDateFormat
, java.sql.Date
等。 The Joda-Time team also advises migration to java.time. Joda-Time团队还建议迁移到java.time。
Instant
The Instant
class represents a moment on the timeline in UTC with a resolution up to nanoseconds. Instant
类表示UTC时间轴上的一个时刻,分辨率高达纳秒。
long mnSeconds = … ;
long mnNanoseconds = … ;
Instant instant = Instant.ofEpochSecond( mnSeconds ).plusNanos( mnNanoseconds );
Or pass both numbers to the of
, as two arguments. 或者将两个数字都传递给
of
,作为两个参数。 Different syntax, same result. 语法不同,结果相同。
Instant instant = Instant.ofEpochSecond( mnSeconds , mnNanoseconds );
To get a String representing this date-time value, call Instant::toString
. 要获取表示此日期时间值的String,请调用
Instant::toString
。
String output = instant.toString();
You will get a value such as 2011-12-03T10:15:30.987654321Z
, standard ISO 8601 format. 您将获得一个值,例如
2011-12-03T10:15:30.987654321Z
,标准ISO 8601格式。 Replace the T
with a SPACE if you wish. 如果您愿意,可以用空格替换
T
For other formats, search Stack Overflow to learn about DateTimeFormatter
. 对于其他格式,请搜索Stack Overflow以了解
DateTimeFormatter
。
The java.time framework is built into Java 8 and later. java.time框架内置于Java 8及更高版本中。 These classes supplant the troublesome old legacy date-time classes such as
java.util.Date
, Calendar
, & SimpleDateFormat
. 这些类取代了麻烦的旧遗留日期时间类,如
java.util.Date
, Calendar
和SimpleDateFormat
。
The Joda-Time project, now in maintenance mode , advises migration to the java.time classes. 现在处于维护模式的Joda-Time项目建议迁移到java.time类。
To learn more, see the Oracle Tutorial . 要了解更多信息,请参阅Oracle教程 。 And search Stack Overflow for many examples and explanations.
并搜索Stack Overflow以获取许多示例和解释。 Specification is JSR 310 .
规范是JSR 310 。
You may exchange java.time objects directly with your database. 您可以直接与数据库交换java.time对象。 Use a JDBC driver compliant with JDBC 4.2 or later.
使用符合JDBC 4.2或更高版本的JDBC驱动程序 。 No need for strings, no need for
java.sql.*
classes. 不需要字符串,不需要
java.sql.*
类。
Where to obtain the java.time classes? 从哪里获取java.time类?
The ThreeTen-Extra project extends java.time with additional classes. ThreeTen-Extra项目使用其他类扩展了java.time。 This project is a proving ground for possible future additions to java.time.
该项目是未来可能添加到java.time的试验场。 You may find some useful classes here such as
Interval
, YearWeek
, YearQuarter
, and more . 您可以在这里找到一些有用的类,比如
Interval
, YearWeek
, YearQuarter
,和更多 。
It depends a bit on the values of you mnSeconds and mnNanoseconds but all you need to do with a formatter like that one (which has millisecond precision) is to create a java.util.Date. 它取决于你的mnSeconds和mnNanoseconds的值,但你需要做的就是那个格式化程序(具有毫秒精度),就是创建一个java.util.Date。 If mnNanoseconds is the number of nanoseconds on top of your mnSeconds, I would assume it to be something like
如果mnNanoseconds是mnSeconds之上的纳秒数,我会认为它类似于
Date d = new Date(mnSeconds*1000+mnNanosecods/1000000)
Then it is a matter of formatting it with your formatter before printing it. 然后在打印之前用格式化程序格式化它。
You can use 您可以使用
new java.util.Date(mnSeconds);
and then SimpleDateFormat to format your output. 然后使用SimpleDateFormat格式化输出。
Nanoseconds are not supported by Date. Date不支持纳秒。 You have to manually add Nanoseconds or use some framework (is there one?).
你必须手动添加纳秒或使用一些框架(有一个吗?)。
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