如何从 Java 8 中的 LocalTime 中删除毫秒
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How to remove milliseconds from LocalTime in java 8
提问by Nikolas
Using the java.time framework, I want to print time in format hh:mm:ss, but LocalTime.now()gives the time in the format hh:mm:ss,nnn. I tried to use DateTimeFormatter:
使用 java.time 框架，我想以 format 打印时间hh:mm:ss，但以 formatLocalTime.now()给出时间hh:mm:ss,nnn。我尝试使用DateTimeFormatter：
DateTimeFormatter formatter = DateTimeFormatter.ISO_LOCAL_TIME;
LocalTime time = LocalTime.now();
String f = formatter.format(time);
System.out.println(f);
The result:
结果：
22:53:51.894
How can I remove milliseconds from the time?
如何从时间中删除毫秒？
采纳答案by Jon Skeet
Just create the DateTimeFormatterexplicitly:
只需DateTimeFormatter明确创建：
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("HH:mm:ss", Locale.US);
LocalTime time = LocalTime.now();
String f = formatter.format(time);
System.out.println(f);
(I prefer to explicitly use the US locale, to make it clear that I don'twant anything from the default format locale.)
（我更喜欢明确使用美国语言环境，以明确表示我不想要默认格式语言环境中的任何内容。）
回答by demos74dx
Edit: I should add that these are nanoseconds not milliseconds.
编辑：我应该补充一点，这些是纳秒而不是毫秒。
I feel these answers don't really answer the question using the Java 8 SE Date and Time API as intended. I believe the truncatedTo method is the solution here.
我觉得这些答案并没有像预期的那样使用 Java 8 SE 日期和时间 API 真正回答问题。我相信 truncatedTo 方法是这里的解决方案。
LocalDateTime now = LocalDateTime.now();
System.out.println("Pre-Truncate: " + now);
DateTimeFormatter dtf = DateTimeFormatter.ISO_DATE_TIME;
System.out.println("Post-Truncate: " + now.truncatedTo(ChronoUnit.SECONDS).format(dtf));
Output:
输出：
Pre-Truncate: 2015-10-07T16:40:58.349
Post-Truncate: 2015-10-07T16:40:58
Alternatively, if using Time Zones:
或者，如果使用时区：
LocalDateTime now = LocalDateTime.now();
ZonedDateTime zoned = now.atZone(ZoneId.of("America/Denver"));
System.out.println("Pre-Truncate: " + zoned);
DateTimeFormatter dtf = DateTimeFormatter.ISO_OFFSET_DATE_TIME;
System.out.println("Post-Truncate: " + zoned.truncatedTo(ChronoUnit.SECONDS).format(dtf));
Output:
输出：
Pre-Truncate: 2015-10-07T16:38:53.900-06:00[America/Denver]
Post-Truncate: 2015-10-07T16:38:53-06:00
回答by Mike_vin
cut to minutes:
缩短到分钟：
localTime.truncatedTo(ChronoUnit.MINUTES);
cut to seconds:
切到秒：
localTime.truncatedTo(ChronoUnit.SECONDS);
Example:
例子：
LocalTime.now().truncatedTo(ChronoUnit.SECONDS).format(DateTimeFormatter.ISO_LOCAL_TIME)
Outputs 15:07:25
输出 15:07:25
回答by Justin
Use this in your first line
在你的第一行使用它
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("HH:mm:ss");
回答by dpassy
Try to use patterns defined here: http://docs.oracle.com/javase/8/docs/api/java/time/format/DateTimeFormatter.html
尝试使用此处定义的模式：http: //docs.oracle.com/javase/8/docs/api/java/time/format/DateTimeFormatter.html
For example:
例如：
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy MM dd HH. mm. ss");
String text = date.toString(formatter);
回答by Bohemian
You can so it simply by using regex on the string:
您只需在字符串上使用正则表达式即可：
String f = formatter.format(time).replaceAll("\.[^.]*", "");
This deletes (by replacing with blank) the last dot and everything after.
这将删除（通过替换为空白）最后一个点和之后的所有内容。
