blocks|key|5293143|text|我个人更喜欢|type|unstyled|depth|inlineStyleRanges|entityRanges|data|5293144|LocalDateTime.now(ZoneOffset.UTC);|code-block|syntax|javascript|5293145|因为它是最具可读性的选项。|5293146|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

I personally prefer 

<pre><code>LocalDateTime.now(ZoneOffset.UTC);
</code></pre>

as it is the most readable option.

blocks|key|3875741|text|LocalDateTime不包含区域信息。ZonedDatetime就是这样。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3875742|如果你想把LocalDateTime转换成UTC，你需要用ZonedDateTime的拳头包装。|3875743|你可以像下面这样转换。|3875744|LocalDateTime+ldt+=+LocalDateTime.now();
System.out.println(ldt.toLocalTime());

ZonedDateTime+ldtZoned+=+ldt.atZone(ZoneId.systemDefault());

ZonedDateTime+utcZoned+=+ldtZoned.withZoneSameInstant(ZoneId.of("UTC"));

System.out.println(utcZoned.toLocalTime());|code-block|syntax|javascript|3875745|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|N|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|O|8|@]|9|@]|A|$]]|$1|F|3|G|5|H|7|P|8|@]|9|@]|A|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

LocalDateTime does not contain Zone information. ZonedDatetime does.

If you want to convert LocalDateTime to UTC, you need to wrap by ZonedDateTime fist.

You can convert like the below.

<pre><code>LocalDateTime ldt = LocalDateTime.now();
System.out.println(ldt.toLocalTime());

ZonedDateTime ldtZoned = ldt.atZone(ZoneId.systemDefault());

ZonedDateTime utcZoned = ldtZoned.withZoneSameInstant(ZoneId.of("UTC"));

System.out.println(utcZoned.toLocalTime());
</code></pre>

blocks|key|3875696|text|还有一种更简单的方法|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3875697|LocalDateTime.now(Clock.systemUTC())|code-block|syntax|javascript|3875698|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

There is an even simpler way

<pre><code>LocalDateTime.now(Clock.systemUTC())
</code></pre>

blocks|key|3875659|text|使用下面的代码。它获取本地日期时间，并使用时区将其转换为UTC。您不需要创建它的函数。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3875660|ZonedDateTime+nowUTC+=+ZonedDateTime.now(ZoneOffset.UTC);
System.out.println(nowUTC.toString());|code-block|syntax|javascript|3875661|如果您需要获取ZonedDateTime的LocalDateTime部分，那么可以使用以下命令。|3875662|nowUTC.toLocalDateTime();|3875663|下面是我在应用程序中使用的一个静态方法，用于在mysql中插入UTC时间，因为我不能将默认值UTC_TIMESTAMP添加到日期时间列中。|offset|length|style|BOLD|3875664|public+static+LocalDateTime+getLocalDateTimeInUTC(){
++++ZonedDateTime+nowUTC+=+ZonedDateTime.now(ZoneOffset.UTC);

++++return+nowUTC.toLocalDateTime();
}|3875665|entityMap^0|0|0|0|0|1A|D|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|W|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|Y|8|@$M|Z|N|10|O|P]]|9|@]|A|$]]|$1|Q|3|R|5|D|7|11|8|@]|9|@]|A|$E|F]]|$1|S|3|-4|5|6|7|12|8|@]|9|@]|A|$]]]|T|$]]

Use the below. It takes the local datetime and converts it to UTC using the timezone. You do not need to create it function.

<pre><code>ZonedDateTime nowUTC = ZonedDateTime.now(ZoneOffset.UTC);
System.out.println(nowUTC.toString());
</code></pre>

If you need to obtain the LocalDateTime part of the ZonedDateTime then you can use the following.

<pre><code>nowUTC.toLocalDateTime();
</code></pre>

Here is a static method i use in my application to insert UTC time in mysql since i cannot add a default value UTC_TIMESTAMP to a datetime column.

<pre><code>public static LocalDateTime getLocalDateTimeInUTC(){
 ZonedDateTime nowUTC = ZonedDateTime.now(ZoneOffset.UTC);

 return nowUTC.toLocalDateTime();
}
</code></pre>

blocks|key|1501038|text|下面是一个简单的小实用程序类，您可以使用它将本地日期时间从区域转换为区域，包括一个直接将本地日期时间从当前区域转换为UTC的实用程序方法(使用main方法，以便您可以运行它并查看简单测试的结果)：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1501039|import+java.time.LocalDateTime;
import+java.time.ZoneId;
import+java.time.ZoneOffset;
import+java.time.ZonedDateTime;

public+final+class+DateTimeUtil+{
++++private+DateTimeUtil()+{
++++++++super();
++++}

++++public+static+void+main(final+String...+args)+{
++++++++final+LocalDateTime+now+=+LocalDateTime.now();
++++++++final+LocalDateTime+utc+=+DateTimeUtil.toUtc(now);

++++++++System.out.println("Now:+"+%2B+now);
++++++++System.out.println("UTC:+"+%2B+utc);
++++}

++++public+static+LocalDateTime+toZone(final+LocalDateTime+time,+final+ZoneId+fromZone,+final+ZoneId+toZone)+{
++++++++final+ZonedDateTime+zonedtime+=+time.atZone(fromZone);
++++++++final+ZonedDateTime+converted+=+zonedtime.withZoneSameInstant(toZone);
++++++++return+converted.toLocalDateTime();
++++}

++++public+static+LocalDateTime+toZone(final+LocalDateTime+time,+final+ZoneId+toZone)+{
++++++++return+DateTimeUtil.toZone(time,+ZoneId.systemDefault(),+toZone);
++++}

++++public+static+LocalDateTime+toUtc(final+LocalDateTime+time,+final+ZoneId+fromZone)+{
++++++++return+DateTimeUtil.toZone(time,+fromZone,+ZoneOffset.UTC);
++++}

++++public+static+LocalDateTime+toUtc(final+LocalDateTime+time)+{
++++++++return+DateTimeUtil.toUtc(time,+ZoneId.systemDefault());
++++}
}|code-block|syntax|javascript|1501040|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Here's a simple little utility class that you can use to convert local date times from zone to zone, including a utility method directly to convert a local date time from the current zone to UTC (with main method so you can run it and see the results of a simple test):

<pre><code>import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.ZoneOffset;
import java.time.ZonedDateTime;

public final class DateTimeUtil {
 private DateTimeUtil() {
 super();
 }

 public static void main(final String... args) {
 final LocalDateTime now = LocalDateTime.now();
 final LocalDateTime utc = DateTimeUtil.toUtc(now);

 System.out.println("Now: " + now);
 System.out.println("UTC: " + utc);
 }

 public static LocalDateTime toZone(final LocalDateTime time, final ZoneId fromZone, final ZoneId toZone) {
 final ZonedDateTime zonedtime = time.atZone(fromZone);
 final ZonedDateTime converted = zonedtime.withZoneSameInstant(toZone);
 return converted.toLocalDateTime();
 }

 public static LocalDateTime toZone(final LocalDateTime time, final ZoneId toZone) {
 return DateTimeUtil.toZone(time, ZoneId.systemDefault(), toZone);
 }

 public static LocalDateTime toUtc(final LocalDateTime time, final ZoneId fromZone) {
 return DateTimeUtil.toZone(time, fromZone, ZoneOffset.UTC);
 }

 public static LocalDateTime toUtc(final LocalDateTime time) {
 return DateTimeUtil.toUtc(time, ZoneId.systemDefault());
 }
}
</code></pre>

blocks|key|1501085|text|有问题吗？|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1501086|从答案和问题来看，这个问题似乎已经被显著修改了。因此，要回答当前的问题：|1501087|1501088|在UTC中将LocalDateTime转换为LocalDateTime。|blockquote|1501089|1501090|1501091|时区？|1501092|LocalDateTime不存储任何有关时区的信息，它基本上只保存年、月、日、小时、分钟、秒和更小单位的值。所以一个重要的问题是:原始LocalDateTime**?**的时区是什么?它可能已经是了，因此不需要进行转换。|offset|length|style|CODE|BOLD|1501093|系统默认时区|1501094|考虑到您提出了这个问题，您的意思可能是原始时间在您的系统默认时区，并且您希望将其转换为UTC。因为通常使用LocalDateTime.now()创建LocalDateTime对象，它返回系统默认时区中的当前时间。在这种情况下，转换将如下所示：|1501095|LocalDateTime+convertToUtc(LocalDateTime+time)+{
++++return+time.atZone(ZoneId.systemDefault()).withZoneSameInstant(ZoneOffset.UTC).toLocalDateTime();
}|code-block|syntax|javascript|1501096|转换过程的一个示例：|1501097|2019-02-25+11:39+//+[time]+original+LocalDateTime+without+a+timezone
2019-02-25+11:39+GMT%2B1+//+[atZone]+converted+to+ZonedDateTime+(system+timezone+is+Madrid)
2019-02-25+10:39+GMT+//+[withZoneSameInstant]+converted+to+UTC,+still+as+ZonedDateTime
2019-02-25+10:39+//+[toLocalDateTime]+losing+the+timezone+information|1501098|显式时区|1501099|在任何其他情况下，当您显式指定要转换的时间的时区时，转换将如下所示：|1501100|LocalDateTime+convertToUtc(LocalDateTime+time,+ZoneId+zone)+{
++++return+time.atZone(zone).withZoneSameInstant(ZoneOffset.UTC).toLocalDateTime();
}|1501101|1501102|2019-02-25+11:39+//+[time]+original+LocalDateTime+without+a+timezone
2019-02-25+11:39+GMT%2B2+//+[atZone]+converted+to+ZonedDateTime+(zone+is+Europe/Tallinn)
2019-02-25+09:39+GMT+//+[withZoneSameInstant]+converted+to+UTC,+still+as+ZonedDateTime
2019-02-25+09:39+//+[toLocalDateTime]+losing+the+timezone+information|1501103|atZone()方法|1501104|atZone()方法的结果取决于作为其参数传递的时间，因为它考虑了时区的所有规则，包括夏令时。在示例中，时间是2月25日，在欧洲这意味着冬季时间(无DST)。|1501105|如果我们使用不同的日期，假设是去年的8月25日，那么考虑到DST，结果将会不同：|1501106|2018-08-25+11:39+//+[time]+original+LocalDateTime+without+a+timezone
2018-08-25+11:39+GMT%2B3+//+[atZone]+converted+to+ZonedDateTime+(zone+is+Europe/Tallinn)
2018-08-25+08:39+GMT+//+[withZoneSameInstant]+converted+to+UTC,+still+as+ZonedDateTime
2018-08-25+08:39+//+[toLocalDateTime]+losing+the+timezone+information|1501107|GMT时间不变。因此，调整了其他时区中的偏移量。在此示例中，爱沙尼亚的夏季时间为GMT%2B3，冬季时间为GMT%2B2。|1501108|另外，如果您指定了将时钟向后调一小时的过渡时间。例如，2018年10月28日03:30对于爱沙尼亚，这可能意味着两个不同的时间：|1501109|2018-10-28+03:30+GMT%2B3+//+summer+time+[UTC+2018-10-28+00:30]
2018-10-28+04:00+GMT%2B3+//+clocks+are+turned+back+1+hour+[UTC+2018-10-28+01:00]
2018-10-28+03:00+GMT%2B2+//+same+as+above+[UTC+2018-10-28+01:00]
2018-10-28+03:30+GMT%2B2+//+winter+time+[UTC+2018-10-28+01:30]|1501110|如果不手动指定偏移量(GMT%2B2或GMT%2B3)，则时区Europe/Tallinn的时间03:30可以表示两个不同的协调世界时时间和两个不同的偏移量。|1501111|摘要|1501112|正如您所看到的，最终结果取决于作为参数传递的时间的时区。因为不能从LocalDateTime对象中提取时区，所以您必须自己知道它来自哪个时区，才能将其转换为UTC。|1501113|entityMap^0|0|0|0|0|0|0|0|0|D|1V|D|1V|F|2Q|C|0|0|6|0|0|3D|1H|J|22|D|0|0|0|A|0|0|0|4|0|0|Y|0|0|0|A|0|0|0|A|0|8|0|0|27|0|8|0|0|14|0|0|0|1L|0|0|1S|0|0|0|23|R|E|18|5|0|0|2|0|0|2A|X|D|0^^$0|@$1|2|3|4|5|6|7|20|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|21|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|22|8|@]|9|@]|A|$]]|$1|E|3|F|5|G|7|23|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|24|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|25|8|@]|9|@]|A|$]]|$1|J|3|K|5|6|7|26|8|@]|9|@]|A|$]]|$1|L|3|M|5|6|7|27|8|@$N|28|O|29|P|Q]|$N|2A|O|2B|P|Q]|$N|2C|O|2D|P|R]|$N|2E|O|2F|P|R]]|9|@]|A|$]]|$1|S|3|T|5|6|7|2G|8|@$N|2H|O|2I|P|R]]|9|@]|A|$]]|$1|U|3|V|5|6|7|2J|8|@$N|2K|O|2L|P|R]|$N|2M|O|2N|P|Q]|$N|2O|O|2P|P|Q]]|9|@]|A|$]]|$1|W|3|X|5|Y|7|2Q|8|@]|9|@]|A|$Z|10]]|$1|11|3|12|5|6|7|2R|8|@$N|2S|O|2T|P|R]]|9|@]|A|$]]|$1|13|3|14|5|Y|7|2U|8|@]|9|@]|A|$Z|10]]|$1|15|3|16|5|6|7|2V|8|@$N|2W|O|2X|P|R]]|9|@]|A|$]]|$1|17|3|18|5|6|7|2Y|8|@$N|2Z|O|30|P|R]]|9|@]|A|$]]|$1|19|3|1A|5|Y|7|31|8|@]|9|@]|A|$Z|10]]|$1|1B|3|12|5|6|7|32|8|@$N|33|O|34|P|R]]|9|@]|A|$]]|$1|1C|3|1D|5|Y|7|35|8|@]|9|@]|A|$Z|10]]|$1|1E|3|1F|5|6|7|36|8|@$N|37|O|38|P|R]|$N|39|O|3A|P|Q]]|9|@]|A|$]]|$1|1G|3|1H|5|6|7|3B|8|@$N|3C|O|3D|P|R]|$N|3E|O|3F|P|Q]]|9|@]|A|$]]|$1|1I|3|1J|5|6|7|3G|8|@$N|3H|O|3I|P|R]]|9|@]|A|$]]|$1|1K|3|1L|5|Y|7|3J|8|@]|9|@]|A|$Z|10]]|$1|1M|3|1N|5|6|7|3K|8|@$N|3L|O|3M|P|R]]|9|@]|A|$]]|$1|1O|3|1P|5|6|7|3N|8|@$N|3O|O|3P|P|R]]|9|@]|A|$]]|$1|1Q|3|1R|5|Y|7|3Q|8|@]|9|@]|A|$Z|10]]|$1|1S|3|1T|5|6|7|3R|8|@$N|3S|O|3T|P|R]|$N|3U|O|3V|P|Q]|$N|3W|O|3X|P|Q]]|9|@]|A|$]]|$1|1U|3|1V|5|6|7|3Y|8|@$N|3Z|O|40|P|R]]|9|@]|A|$]]|$1|1W|3|1X|5|6|7|41|8|@$N|42|O|43|P|R]|$N|44|O|45|P|Q]]|9|@]|A|$]]|$1|1Y|3|-4|5|6|7|46|8|@]|9|@]|A|$]]]|1Z|$]]

<h2>Question?</h2>

Looking at the answers and the question, it seems the question has been modified significantly. So to answer the current question:

<blockquote>
 Convert LocalDateTime to LocalDateTime in UTC.
</blockquote>

<h2>Timezone?</h2>

<code>LocalDateTime</code> does not store any information about the time-zone, it just basically holds the values of year, month, day, hour, minute, second, and smaller units. So an important question is: What is the timezone of the original <code>LocalDateTime</code>? It might as well be UTC already, therefore no conversion has to be made.

<h2>System Default Timezone</h2>

Considering that you asked the question anyway, you probably meant that the original time is in your system-default timezone and you want to convert it to UTC. Because usually a <code>LocalDateTime</code> object is created by using <code>LocalDateTime.now()</code> which returns the current time in the system-default timezone. In this case, the conversion would be the following:

<pre><code>LocalDateTime convertToUtc(LocalDateTime time) {
 return time.atZone(ZoneId.systemDefault()).withZoneSameInstant(ZoneOffset.UTC).toLocalDateTime();
}
</code></pre>

An example of the conversion process:

<pre><code>2019-02-25 11:39 // [time] original LocalDateTime without a timezone
2019-02-25 11:39 GMT+1 // [atZone] converted to ZonedDateTime (system timezone is Madrid)
2019-02-25 10:39 GMT // [withZoneSameInstant] converted to UTC, still as ZonedDateTime
2019-02-25 10:39 // [toLocalDateTime] losing the timezone information
</code></pre>

<h2>Explicit Timezone</h2>

In any other case, when you explicitly specify the timezone of the time to convert, the conversion would be the following:

<pre><code>LocalDateTime convertToUtc(LocalDateTime time, ZoneId zone) {
 return time.atZone(zone).withZoneSameInstant(ZoneOffset.UTC).toLocalDateTime();
}
</code></pre>

An example of the conversion process:

<pre><code>2019-02-25 11:39 // [time] original LocalDateTime without a timezone
2019-02-25 11:39 GMT+2 // [atZone] converted to ZonedDateTime (zone is Europe/Tallinn)
2019-02-25 09:39 GMT // [withZoneSameInstant] converted to UTC, still as ZonedDateTime
2019-02-25 09:39 // [toLocalDateTime] losing the timezone information
</code></pre>

<h2>The <code>atZone()</code> Method</h2>

The result of the <code>atZone()</code> method depends on the time passed as its argument, because it considers all the rules of the timezone, including Daylight Saving Time (DST). In the examples, the time was 25th February, in Europe this means winter time (no DST).

If we were to use a different date, let's say 25th August from last year, the result would be different, considering DST:

<pre><code>2018-08-25 11:39 // [time] original LocalDateTime without a timezone
2018-08-25 11:39 GMT+3 // [atZone] converted to ZonedDateTime (zone is Europe/Tallinn)
2018-08-25 08:39 GMT // [withZoneSameInstant] converted to UTC, still as ZonedDateTime
2018-08-25 08:39 // [toLocalDateTime] losing the timezone information
</code></pre>

The GMT time does not change. Therefore the offsets in the other timezones are adjusted. In this example, the summer time of Estonia is GMT+3, and winter time GMT+2.

Also, if you specify a time within the transition of changing clocks back one hour. E.g. October 28th, 2018 03:30 for Estonia, this can mean two different times:

<pre><code>2018-10-28 03:30 GMT+3 // summer time [UTC 2018-10-28 00:30]
2018-10-28 04:00 GMT+3 // clocks are turned back 1 hour [UTC 2018-10-28 01:00]
2018-10-28 03:00 GMT+2 // same as above [UTC 2018-10-28 01:00]
2018-10-28 03:30 GMT+2 // winter time [UTC 2018-10-28 01:30]
</code></pre>

Without specifying the offset manually (GMT+2 or GMT+3), the time <code>03:30</code> for the timezone <code>Europe/Tallinn</code> can mean two different UTC times, and two different offsets.

<h2>Summary</h2>

As you can see, the end result depends on the timezone of the time passed as an argument. Because the timezone cannot be extracted from the <code>LocalDateTime</code> object, you have to know yourself which timezone it is coming from in order to convert it to UTC.

blocks|key|1505475|text|使用此方法尝试此操作。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1505476|使用+of+方法将您的ZonedDateTime转换为，并传递系统默认时区，或者您也可以使用区域的ZoneId，如ZoneId.of("Australia/Sydney");|offset|length|style|BOLD|CODE|1505477|LocalDateTime+convertToUtc(LocalDateTime+dateTime)+{
++ZonedDateTime+dateTimeInMyZone+=+ZonedDateTime.
++++++++++++++++++++++++++++++++++++++++of(dateTime,+ZoneId.systemDefault());

++return+dateTimeInMyZone
++++++++++++++++++.withZoneSameInstant(ZoneOffset.UTC)
++++++++++++++++++.toLocalDateTime();
++
}|code-block|syntax|javascript|1505478|要转换回您的区域本地日期时间，请使用：|1505479|LocalDateTime+convertFromUtc(LocalDateTime+utcDateTime){
++++return+ZonedDateTime.
++++++++++++of(utcDateTime,+ZoneId.of("UTC"))
++++++++++++.toOffsetDateTime()
++++++++++++.atZoneSameInstant(ZoneId.systemDefault())
++++++++++++.toLocalDateTime();
}|1505480|entityMap^0|0|2|4|R|1O|B|D|1L|U|0|0|0|J|0|0^^$0|@$1|2|3|4|5|6|7|T|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|U|8|@$D|V|E|W|F|G]|$D|X|E|Y|F|G]|$D|Z|E|10|F|H]|$D|11|E|12|F|H]]|9|@]|A|$]]|$1|I|3|J|5|K|7|13|8|@]|9|@]|A|$L|M]]|$1|N|3|O|5|6|7|14|8|@$D|15|E|16|F|G]]|9|@]|A|$]]|$1|P|3|Q|5|K|7|17|8|@]|9|@]|A|$L|M]]|$1|R|3|-4|5|6|7|18|8|@]|9|@]|A|$]]]|S|$]]

Try this using this method.
convert your <code>LocalDateTime</code> to <code>ZonedDateTime</code> by using the of method and pass system default time zone or you can use ZoneId of your zone like <code>ZoneId.of(&quot;Australia/Sydney&quot;);</code>
<pre><code>LocalDateTime convertToUtc(LocalDateTime dateTime) {
 ZonedDateTime dateTimeInMyZone = ZonedDateTime.
 of(dateTime, ZoneId.systemDefault());

 return dateTimeInMyZone
 .withZoneSameInstant(ZoneOffset.UTC)
 .toLocalDateTime();
 
}
</code></pre>
To convert back to your zone local date time use:
<pre><code>LocalDateTime convertFromUtc(LocalDateTime utcDateTime){
 return ZonedDateTime.
 of(utcDateTime, ZoneId.of(&quot;UTC&quot;))
 .toOffsetDateTime()
 .atZoneSameInstant(ZoneId.systemDefault())
 .toLocalDateTime();
}
</code></pre>

blocks|key|1765409|text|tldr:根本没有办法做到这一点；如果你试图做到这一点，你就会把LocalDateTime搞错。|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|1765410|原因是LocalDateTime在实例创建后不会记录时区。不能将不带时区的日期时间转换为基于特定时区的其他日期时间。|1765411|事实上，决不应该在生产代码中调用LocalDateTime.now()，除非您的目的是获得随机结果。当您构建这样一个LocalDateTime实例时，此实例仅包含基于当前服务器时区的日期时间，这意味着如果它运行的服务器具有不同的时区配置，则此代码将生成不同的结果。|1765412|LocalDateTime可以简化日期计算。如果您想要一个真正的通用数据时间，可以使用ZonedDateTime或OffsetDateTime：https://docs.oracle.com/javase/8/docs/api/java/time/OffsetDateTime.html。|1765413|entityMap|0|LINK|mutability|MUTABLE|url|https://docs.oracle.com/javase/8/docs/api/java/time/OffsetDateTime.html^0|W|D|0|3|D|0|G|J|1M|D|0|0|D|20|1Z|0|0^^$0|@$1|2|3|4|5|6|7|T|8|@$9|U|A|V|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|W|8|@$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|Z|8|@$9|10|A|11|B|C]|$9|12|A|13|B|C]]|D|@]|E|$]]|$1|J|3|K|5|6|7|14|8|@$9|15|A|16|B|C]]|D|@$9|17|A|18|1|19]]|E|$]]|$1|L|3|-4|5|6|7|1A|8|@]|D|@]|E|$]]]|M|$N|$5|O|P|Q|E|$R|S]]]]

tldr: there is simply no way to do that; if you are trying to do that, you get LocalDateTime wrong.

The reason is that LocalDateTime does not record Time Zone after instances are created. You cannot convert a date time without time zone to another date time based on a specific time zone.

As a matter of fact, LocalDateTime.now() should never be called in production code unless your purpose is getting random results. When you construct a LocalDateTime instance like that, this instance contains date time ONLY based on current server's time zone, which means this piece of code will generate different result if it is running a server with a different time zone config.

LocalDateTime can simplify date calculating. If you want a real universally usable data time, use ZonedDateTime or OffsetDateTime: <a href="https://docs.oracle.com/javase/8/docs/api/java/time/OffsetDateTime.html" rel="noreferrer">https://docs.oracle.com/javase/8/docs/api/java/time/OffsetDateTime.html</a>.

blocks|key|1500980|text|你可以实现一个帮助器来做这样的事情：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1500981|public+static+LocalDateTime+convertUTCFRtoUTCZ(LocalDateTime+dateTime)+{
++++ZoneId+fr+=+ZoneId.of("Europe/Paris");
++++ZoneId+utcZ+=+ZoneId.of("Z");
++++ZonedDateTime+frZonedTime+=+ZonedDateTime.of(dateTime,+fr);
++++ZonedDateTime+utcZonedTime+=+frZonedTime.withZoneSameInstant(utcZ);
++++return+utcZonedTime.toLocalDateTime();
}|code-block|syntax|javascript|1500982|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

you can implement a helper doing something like that : 

<pre><code>public static LocalDateTime convertUTCFRtoUTCZ(LocalDateTime dateTime) {
 ZoneId fr = ZoneId.of("Europe/Paris");
 ZoneId utcZ = ZoneId.of("Z");
 ZonedDateTime frZonedTime = ZonedDateTime.of(dateTime, fr);
 ZonedDateTime utcZonedTime = frZonedTime.withZoneSameInstant(utcZ);
 return utcZonedTime.toLocalDateTime();
}
</code></pre>

blocks|key|5293015|text|public+static+String+convertFromGmtToLocal(String+gmtDtStr,+String+dtFormat,+TimeZone+lclTimeZone)+throws+Exception{
++++++++if+(gmtDtStr+==+null+%7C%7C+gmtDtStr.trim().equals(""))+return+null;
++++++++SimpleDateFormat+format+=+new+SimpleDateFormat(dtFormat);
++++++++format.setTimeZone(getGMTTimeZone());
++++++++Date+dt+=+format.parse(gmtDtStr);
++++++++format.setTimeZone(lclTimeZone);
++++++++return|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|5293016|format.format(dt)；}|unstyled|5293017|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|J|8|@]|9|@]|A|$]]|$1|G|3|-4|5|F|7|K|8|@]|9|@]|A|$]]]|H|$]]

<pre><code>public static String convertFromGmtToLocal(String gmtDtStr, String dtFormat, TimeZone lclTimeZone) throws Exception{
 if (gmtDtStr == null || gmtDtStr.trim().equals("")) return null;
 SimpleDateFormat format = new SimpleDateFormat(dtFormat);
 format.setTimeZone(getGMTTimeZone());
 Date dt = format.parse(gmtDtStr);
 format.setTimeZone(lclTimeZone);
 return
</code></pre>

format.format(dt);
 }

Convert LocalDateTime to LocalDateTime in UTC.

<pre><code>LocalDateTime convertToUtc(LocalDateTime date) {

 //do conversion

}
</code></pre>

I searched over net. But did not get a solution

Convert LocalDateTime to LocalDateTime in UTC

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

文章

问答

视频

教程

学习中心

腾讯云实验室

直播

竞赛

腾讯云代码分析专区

腾讯iOA零信任安全管理系统专区

腾讯云架构师技术同盟交流圈

腾讯云数据库专区

腾讯云智能顾问专区

腾讯云原生专区

腾讯混元专区

腾讯云TCE专区

腾讯云Lighthouse专区

腾讯云HAI专区

腾讯云Edgeone专区

腾讯云存储专区

腾讯云智能专区

腾讯轻联专区 

腾讯云开发专区

TAPD专区

腾讯轻量云游戏服专区

腾讯云最具价值专家

腾讯云架构师技术同盟

腾讯云创作之星

腾讯云开发者先锋

腾讯云AI代码助手

云原生构建

TAPD 敏捷项目管理

Cloud Studio

SDK中心

API中心

命令行工具

功能1上新10个字符

功能2描述100个字符功能2描述100个字符功能2描述100个字符功能2描述100个字符功能2描述100个字符功能2描述100个字符功能2描述100个字符功能2描述100个字符功能2描述100个字符。

功能2上新100个字符功能2上新100个字符功能2上新100个字符功能2上新100个字符功能2上新100个字符功能2上新100个字符功能2上新100个字符功能2上新100个字符功能2上新100个字符。

功能5描述100个字符功能5描述100个字符功能5描述100个字符功能5描述100个字符功能5描述100个字符功能5描述100个字符

功能5上新100个字符功能5上新100个字符功能5上新100个字符功能5上新100个字符功能5上新100个字符功能5上新100个字符功能5上新100个字符功能5上新100个字符功能5上新100个字符功能5上新100个字符

功能4上新

文章&问答评论现已支持表情

全新交互，全新视觉，新增快捷键、悬浮工具栏、高亮块等功能并同时优化现有功能，全面提升创作效率和体验

社区富文本编辑器全新改版！诚邀体验～ 

精选全网热门MCP server，让你的AI更好用 🚀

💥开发者 MCP广场重磅上线！

涵盖代码开发、场景应用、自动测试全流程，助你从零构建专属AI助手

一站式MCP教程库，解锁AI应用新玩法

聚焦“写作效率、视觉美观与运行性能”三方面进行全面升级，为您提供更高效、稳定的创作环境

社区富文本&Markdown编辑器全新改版上线，欢迎大家体验!

诚挚邀请您参与本次调研，分享您的真实使用感受与建议。您的反馈至关重要，感谢您的支持与参与！

社区新版编辑器体验调研

在UTC中将LocalDateTime转换为LocalDateTime。LocalDateTime convertToUtc(LocalDateTime date) {    //do conversion}我在网上搜索过了。但是没有得到一个解决方案

问将LocalDateTime转换为UTC格式的LocalDateTime
EN

回答 10

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问将LocalDateTime转换为UTC格式的LocalDateTimeEN

回答 10

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问将LocalDateTime转换为UTC格式的LocalDateTime
EN