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How can I set date and time formatting in Java that respects the user's OS settings
(7 answers)
How to get the current date/time in Java [duplicate]
(28 answers)
Closed 3 years ago.
I'm trying to read current system date and time format in java, but after analysing i couldn't find any method regarding this, so can anyone help me out.This is what i want read from java.
To get a DateTimeFormatter for the current system locale, you can use DateTimeFormatter.ofLocalizedDateTime()
The FormatStyle parameter controls whether you want long or short representation (Tuesday, April 12, 1952 AD 3:30:42pm PST versus 12.13.52 3:30pm).
A few examples and what I get on my local system:
//Tuesday, 2 April 2019 at 5:49:39 pm Australian Eastern Daylight Time
DateTimeFormatter.ofLocalizedDateTime(FormatStyle.FULL).format(ZonedDateTime.now())
//2 April 2019 at 5:50:20 pm AEDT
DateTimeFormatter.ofLocalizedDateTime(FormatStyle.LONG).format(ZonedDateTime.now())
//2/4/19, 5:50 pm
DateTimeFormatter.ofLocalizedDateTime(FormatStyle.SHORT).format(ZonedDateTime.now())
You can ask system current time only in milliseconds. And then you can transform them into DateTime:
long timestamp = System.currentTimeMillis();
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm");
Date date = new Date(timestamp);
System.out.println(dateFormat.format(date));
You can't do it with just the Java API. The system date-time format is operating system specific, and Java has no API to read that (you can read the date-time, and the locale, but not the format). You would have to find some library that does it or write it yourself - but beware that this is going to be vastly different for every OS. E.g. for Windows you might have to read the Windows registry.
To get the locale: Locale.getDefault()
From the locale, you can probably assume the format in most cases (but not if the user chose an untypical format).
Related
This question already has answers here:
LocalDate to java.util.Date and vice versa simplest conversion? [duplicate]
(7 answers)
How do I get a Date without time in Java?
(23 answers)
Closed 3 years ago.
I want to get a Date without time, but always failed.
below is my codes:
long curLong = System.currentTimeMillis();
curLong = curLong - curLong % TimeUnit.DAYS.toMillis(1);
Date date = new Date(curLong);
System.out.println("date = " + date);
the output:
date = Mon Oct 28 08:00:00 CST 2019
anyone knows why? Thank you
It is not recommended to use java.util.Date anymore. It was called Date but doesn't necessarily hold only the date information but information about the time additionally.
Use this:
LocalDate today = LocalDate.now();
and print it as
System.out.println(today.format(DateTimeFormatter.ISO_DATE);
using the ISO date format. You can define your own formatting pattern using a
DateTimeFormatter.ofPattern("dd.MM.yyyy");
for example.
You can use java.time.LocalDate.now() to get just the date.
Anyway, your case doesn't work as you expect because you are doing nothing to remove the time from the date: you are just "repressing" it, that's why it's zero. If you want to continue this way you could always substring it (substring the Date.toString() of course I meant).
Hope I helped.
java.util.Date's javadoc states:
The class Date represents a specific instant in time, with millisecond precision.
Thats why you have date with time
If you want a date you can use : java.time.LocalDate.now() (Java 8+)
First of all, stop using the old java.util.Date. The new Java 8 date and time API has much better classes for all date and time operations.
The LocalDate class does exactly what you want.
The current date can be obtained by LocalDate.now().
It also has a lot of facilities to add and subtract days, months etc. and it takes into consideration all the calendar special cases for you.
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Parsing ISO 8601 date format like 2015-06-27T13:16:37.363Z in Java [duplicate]
(2 answers)
Closed 4 years ago.
I need to transform a Twitter timestampe into a Java Date object,
here is an example of a value of a Timestampe: "2015-01-06T21:07:00Z"
Can you please give me sample of java code (standard Java) doing the job?
Thank you
I recommend you take advantage of the new Date/Time API introduced in Java 8, specifically Instant as follows:
Instant.parse("2015-01-06T21:07:00Z");
You can then perform a multitude of operations, but keep in mind that the object is immutable, so any changes to the instance (that aren't chained) must be stored in a separate variable.
Actually it is ISO 8601 format for UTC time zone.
It conforms with XML DateTime format as well.
So, to get actual java.util.Calendar or java.util.Date out of it you simply can use available in JDK
Calendar twitterCalendar = javax.xml.bind.DatatypeConverter.parseDateTime("2015-01-06T21:07:00Z");
Date twitterDate = javax.xml.bind.DatatypeConverter.parseDateTime("2015-01-06T21:07:00Z").getTime();
Just be aware: java.util.Date has no Time Zone information in it. Your string is in UTC, so if you try to print value of twitterDate you will see Date/Time in TimeZone of your computer/server. Still actual value of twitterDate stays the same
millisecond value that is an offset from the Epoch, January 1, 1970 00:00:00.000 GMT (Gregorian).
This question already has answers here:
Generic support for ISO 8601 format in Java 6
(2 answers)
Closed 7 years ago.
I have the following strings which are coming from external server -
"2015-02-25T04:23:34.874-08:00", "2015-02-25T12:22:49.275Z"
I have to show these strings in my site along with the time zone which is available in the above strings.
Following is the format to show the date in my site -
"Feb 25, 2015 03:23 AM, GMT-08:00", "Feb 25, 2015 12:22 AM, GMT"
In JAVA 7 we have new pattern character 'X' to resolve this. We can parse both these values using the single pattern
"yyyy-MM-dd'T'HH:mm:ss.SSSXXX"
But I am stuck with JAVA 6. What is the right pattern to use for JAVA 6 ?
The incoming date does not depict the timezone, still if you are sure that you would be getting all times in GMT, then you can simply format the incoming date using SimpleDateFormat and get you desired format.
You have an XSD dateTime on your hands which is notoriously hard to parse using standard java (this might have changed in java 8?)
The timezone is not compatible with the SimpleDateFormat parser nor is the random number of milliseconds (can be more than 3 per the spec).
I have not used it but I'm pretty sure Joda time has an easy solution for this. In case you're interested, here is some custom code I wrote a long time ago that parses them as well: https://github.com/nablex/types-base/blob/master/src/main/java/be/nabu/libs/types/utils/TimeFormat.java
DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
dateFormat.format("2015-02-25T04:23:34.874-08:00")
The format is customizable.
This question already has answers here:
Closed 10 years ago.
I need to get real world date and time in Java. I use:
Date date = new Date();
But I'm not sure that it is not just system time. I don't need to be dependent on PC local date and time.
If it is so, then is there any way to abstract from it? I mean I need correct time and date. If today is the 1st of May, 2012 and user changed (maybe there was a system error) it to the 1st of December 2000, it shouldn't affect business logic. So is there any alternative to achieve this?
Date only represents an instant in time, in milliseconds since the Unix epoch of January 1st 1970 UTC (modulo leap seconds). It has no concept of a time zone in its data. However, if you use the toString method it will always convert that UTC instant to a local date/time using the system time zone. That confuses a lot of users, making them think that Date contains a time zone - it's just an illusion.
Likewise Date doesn't have any concept of a calendar system (Gregorian, Julian etc) or a "format". Basically it's just a long :)
This question already has answers here:
Closed 11 years ago.
Possible Duplicate:
How to get the current date and time of your timezone in Java?
I have developed a Attendance System and in use for India. Our servers are in US and since they are using PDT. My code reflects time one hour ahead.
say its 9:00 am IST ---- I get the time as 10:00 am IST
other than detecting one hour from the time, which will be a temporary solution.
Pls suggest me some way to overcome this situation
To check if a given Date is affected by daylight saving, use
Calendar c = Calendar.getInstance(timezone); // omit timezone for default tz
c.setTime(date); // your date; omit this line for current date
int offset = c.get(Calendar.DST_OFFSET);
0 means no DST, any other value (most likely 3600000) means that this date is affected by DST