What is the Java8 java.time equivalent of
org.joda.time.formatDateTimeFormat.shortDate()
I've tried below way, but it fails to parse values such as "20/5/2016" or "20/5/16".
DateTimeFormatter.ofLocalizedDate(FormatStyle.SHORT)
You are correct: A Joda-Time DateTimeFormatter (which is the type you get from DateTimeFormat.shortDate()) parses more leniently than a java.time DateTimeFormatter. In the English/New Zealand locale (en-NZ) shortDate uses the format pattern d/MM/yy and parses both 20/5/2016 and 20/5/16 into 2016-05-20.
I frankly find it nasty that it interprets both two-digit and four-digit years into the same year. When the format specifies two-digit year, I would have expected four digits to be an error for stricter input validation. Accepting one-digit month when the format specifies two digits is lenient too, but maybe not so dangerous and more in line with what we might expect.
java.time too uses the format pattern d/MM/yy (tested on jdk-11.0.3). When parsing is accepts one or two digits for day of month, but insist on two-digit month and two-digit year.
You may get the Joda-Time behaviour in java.time, but it requires you to specify the format pattern yourself:
Locale loc = Locale.forLanguageTag("en-NZ");
DateTimeFormatter dateFormatter
= DateTimeFormatter.ofPattern("d/M/[yyyy][yy]", loc);
System.out.println(LocalDate.parse("20/5/2016", dateFormatter));
System.out.println(LocalDate.parse("20/5/16", dateFormatter));
Output is:
2016-05-20
2016-05-20
If you want an advanced solution that works in other locales, I am sure that you can write a piece of code that gets the format pattern from DateTimeFormatterBuilder.getLocalizedDateTimePattern and modifies it by replacing dd with d, MM with M and any number of y with [yyyy][yy]. Then pass the modified format pattern string to DateTimeFormatter.ofPattern.
Edit: I’m glad that you got something to work. In your comment you said that you used:
Stream<String> shortFormPatterns = Stream.of(
"[d][dd]/[M][MM]",
"[d][dd]-[M][MM]",
"[d][dd].[M][MM]",
"[d][dd] [M][MM]",
"[d][dd]/[M][MM]/[yyyy][yy]",
"[d][dd]-[M][MM]-[yyyy][yy]",
"[d][dd].[M][MM].[yyyy][yy]",
"[d][dd] [M][MM] [yyyy][yy]");
It covers more cases that your Joda-Time formatter. Maybe that’s good. Specifically your Joda-Time formatter insists on a slash / between the numbers and rejects either hyphen, dot or space. Also I believe that Joda-Time would object to the year being left out completely.
While you do need [yyyy][yy], you don’t need [d][dd] nor [M][MM]. Just d and M suffice since they also accept two digits (what happens in your code is that for example [d] parses either one or two digits, so [dd] is never used anyway).
If you prefer only one format pattern string, I would expect d[/][-][.][ ]M[/][-][.][ ][yyyy][yy] to work (except in hte cases where the year is omitted) (I haven’t tested).
FormatStyle.SHORT returns shortest format either dd/MM/yy or d/M/yy format, so you need to use pattern to get the customized format
LocalDate date = LocalDate.now();
System.out.println(date.format(DateTimeFormatter.ofLocalizedDate(FormatStyle.SHORT))); //9/29/19
You can also use DateTimeFormatter.ISO_DATE or DateTimeFormatter.ISO_LOCAL_DATE to get the iso format like yyyy-MM-dd, and also you can see the available formats in DateTimeFormatter
System.out.println(date.format(DateTimeFormatter.ISO_DATE)); //2019-09-29
System.out.println(date.format(DateTimeFormatter.ISO_LOCAL_DATE)); //2019-09-29
If you want the custom format like yyyy/MM/dd the use ofPattern
System.out.println(date.format(DateTimeFormatter.ofPattern("yyyy/MM/dd"))); //2019/09/29
I have this code
frame.sigdate.setText(new SimpleDateFormat("yyyy/M/d").format(new Date()));
which reads the date from my PC with English numbers. What I want to do is convert the date to Arabic numbers.
Is there anything like Local.ar ?
I appreciate any help.
java.time
Locale arabicLocale = Locale.forLanguageTag("ar");
DateTimeFormatter arabicDateFormatter
= DateTimeFormatter.ofLocalizedDate(FormatStyle.SHORT)
.withLocale(arabicLocale)
.withDecimalStyle(DecimalStyle.of(arabicLocale));
LocalDate today = LocalDate.now(ZoneId.of("Asia/Muscat"));
System.out.println(today.format(arabicDateFormatter));
Output:
١٥/٤/٢٠١٨
The key is withDecimalStyle. Without this call, the formatter would still use western numerals, as in 15/4/2018. You may want to use a more specific language tag than just ar for Arabic, for example ar-BH for Bahrain or ar-YE for Yemen. See the link at the bottom for possibilities. You should also insert your desired time zone where I put Asia/Muscat.
EDIT: The above has been tested in Java 9. Surprisingly in Java 8 it still uses western (unlocalized) digits. A possible fix (or workaround if you like) is to specify the zero digit explicitly — it will pick up the other digits from it.
DecimalStyle arabicDecimalStyle
= DecimalStyle.of(arabicLocale).withZeroDigit('٠');
DateTimeFormatter arabicDateFormatter
= DateTimeFormatter.ofLocalizedDate(FormatStyle.SHORT)
.withLocale(arabicLocale)
.withDecimalStyle(arabicDecimalStyle);
It’s an Arabic zero between the two apostrophes in the argument to withZeroDigit. Now I get this output on Java 8:
١٥/٠٤/١٨
It’s usually a good idea to use the built-in locale specific formats as I do with ofLocalizedDate in both snippets above. If you need finer control over the format, use ofPattern instead. For example, to get yyyy/mm/dd format:
DateTimeFormatter arabicDateFormatter
= DateTimeFormatter.ofPattern("uuuu/MM/dd", arabicLocale)
.withDecimalStyle(arabicDecimalStyle);
Output:
٢٠١٨/٠٤/١٥
The reason why the format changed from Java 8 to Java 9 is that Java has changed the defaults for where the locale data come from, including the built-in localized date and time formats. You can get the Java 9 format already in Java 8 by setting a system property, for example like this:
System.setProperty("java.locale.providers", "CLDR,JRE,SPI");
With this change the first code snippet above gives the same output on Java 8 as on Java 9:
١٥/٤/٢٠١٨
The important detail here is that CLDR goes first in the property string. And the advantages are you don’t need to specify your own format pattern string, localization to other locales is straightforward and users won’t be surprised by a change in behaviour once you switch to Java 9 or later.
I am using and recommending java.time, the modern Java date and time API. The SimpleDateFormat class that you used in the question is not only long outdated, it is also notoriously troublesome. IMHO you should avoid it completely. The modern API is so much nicer to work with.
Links
Oracle tutorial: Date Time explaining how to use java.time.
List of supported locales in Java 8
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("d/MM/yyyy");
String date = "16/08/2011";
Locale arabicLocale = Locale.forLanguageTag("ar-SA");
DateTimeFormatter arabicDateFormatter = DateTimeFormatter.ofLocalizedDate(FormatStyle.SHORT).withLocale(arabicLocale).withDecimalStyle(DecimalStyle.of(arabicLocale));
LocalDate today = LocalDate.now(ZoneId.of("Asia/Muscat"));
today = LocalDate.parse(date, formatter);
String dat = today.format(arabicDateFormatter);
System.out.println(dat);
out put ١٦/٨/٢٠١١
try below approch
java.util.Locale locale = new java.util.Locale("ar");
java.text.DecimalFormat df = (java.text.DecimalFormat)
java.text.DecimalFormat.getNumberInstance(locale);
DateTime dateTimeObjectInUTC = new DateTime(DateTimeZone.UTC);
DateTimeZone dateTimeZoneObject = DateTimeZone.forID("Asia/Riyadh");
java.util.Locale locale = new Locale("ar","SA");
DateTimeFormatter formatter = DateTimeFormat.forStyle("FF").withLocale(locale).withZone(dateTimeZoneObject);
String output = formatter.print(dateTimeObjectInUTC);
This should help!
I am using Joda-Time. Please refer to the Jodatime documentation. DateTimeZone documentation, for example.
It is quite easy to format and parse Java Date (or Calendar) classes using instances of DateFormat.
I could format the current date into a short localized date like this:
DateFormat formatter = DateFormat.getDateInstance(DateFormat.SHORT, Locale.getDefault());
String today = formatter.format(new Date());
My problem is that I need to obtain this localized pattern string (something like "MM/dd/yy").
This should be a trivial task, but I just couldn't find the provider.
For SimpleDateFormat, You call toLocalizedPattern()
EDIT:
For Java 8 users:
The Java 8 Date Time API is similar to Joda-time. To gain a localized pattern we can use class
DateTimeFormatter
DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM);
Note that when you call toString() on LocalDate, you will get date in format ISO-8601
Note that Date Time API in Java 8 is inspired by Joda Time and most solution can be based on questions related to time.
For those still using Java 7 and older:
You can use something like this:
DateFormat formatter = DateFormat.getDateInstance(DateFormat.SHORT, Locale.getDefault());
String pattern = ((SimpleDateFormat)formatter).toPattern();
String localPattern = ((SimpleDateFormat)formatter).toLocalizedPattern();
Since the DateFormat returned From getDateInstance() is instance of SimpleDateFormat.
Those two methods should really be in the DateFormat too for this to be less hacky, but they currently are not.
It may be strange, that I am answering my own question, but I believe, I can add something to the picture.
ICU implementation
Obviously, Java 8 gives you a lot, but there is also something else: ICU4J. This is actually the source of Java original implementation of things like Calendar, DateFormat and SimpleDateFormat, to name a few.
Therefore, it should not be a surprise that ICU's SimpleDateFormat also contains methods like toPattern() or toLocalizedPattern(). You can see them in action here:
DateFormat fmt = DateFormat.getPatternInstance(
DateFormat.YEAR_MONTH,
Locale.forLanguageTag("pl-PL"));
if (fmt instanceof SimpleDateFormat) {
SimpleDateFormat sfmt = (SimpleDateFormat) fmt;
String pattern = sfmt.toPattern();
String localizedPattern = sfmt.toLocalizedPattern();
System.out.println(pattern);
System.out.println(localizedPattern);
}
ICU enhancements
This is nothing new, but what I really wanted to point out is this:
DateFormat.getPatternInstance(String pattern, Locale locale);
This is a method that can return a whole bunch of locale specific patterns, such as:
ABBR_QUARTER
QUARTER
YEAR
YEAR_ABBR_QUARTER
YEAR_QUARTER
YEAR_ABBR_MONTH
YEAR_MONTH
YEAR_NUM_MONTH
YEAR_ABBR_MONTH_DAY
YEAR_NUM_MONTH_DAY
YEAR_MONTH_DAY
YEAR_ABBR_MONTH_WEEKDAY_DAY
YEAR_MONTH_WEEKDAY_DAY
YEAR_NUM_MONTH_WEEKDAY_DAY
ABBR_MONTH
MONTH
NUM_MONTH
ABBR_STANDALONE_MONTH
STANDALONE_MONTH
ABBR_MONTH_DAY
MONTH_DAY
NUM_MONTH_DAY
ABBR_MONTH_WEEKDAY_DAY
MONTH_WEEKDAY_DAY
NUM_MONTH_WEEKDAY_DAY
DAY
ABBR_WEEKDAY
WEEKDAY
HOUR
HOUR24
HOUR_MINUTE
HOUR_MINUTE_SECOND
HOUR24_MINUTE
HOUR24_MINUTE_SECOND
HOUR_TZ
HOUR_GENERIC_TZ
HOUR_MINUTE_TZ
HOUR_MINUTE_GENERIC_TZ
MINUTE
MINUTE_SECOND
SECOND
ABBR_UTC_TZ
ABBR_SPECIFIC_TZ
SPECIFIC_TZ
ABBR_GENERIC_TZ
GENERIC_TZ
LOCATION_TZ
Sure, there are quite a few. What is good about them, is that these patterns are actually strings (as in java.lang.String), that is if you use English pattern "MM/d", you'll get locale-specific pattern in return. It might be useful in some corner cases. Usually you would just use DateFormat instance, and won't care about the pattern itself.
Locale-specific pattern vs. localized pattern
The question intention was to get localized, and not the locale-specific pattern. What's the difference?
In theory, toPattern() will give you locale-specific pattern (depending on Locale you used to instantiate (Simple)DateFormat). That is, no matter what target language/country you put, you'll get the pattern composed of symbols like y, M, d, h, H, M, etc.
On the other hand, toLocalizedPattern() should return localized pattern, that is something that is suitable for end users to read and understand. For instance, German middle (default) date pattern would be:
toPattern(): dd.MM.yyyy
toLocalizedPattern(): tt.MM.jjjj (day = Tag, month = Monat, year = Jahr)
The intention of the question was: "how to find the localized pattern that could serve as hint as to what the date/time format is". That is, say we have a date field that user can fill-out using the locale-specific pattern, but I want to display a format hint in the localized form.
Sadly, so far there is no good solution. The ICU I mentioned earlier in this post, partially works. That's because, the data that ICU uses come from CLDR, which is unfortunately partially translated/partially correct. In case of my mother's tongue, at the time of writing, neither patterns, nor their localized forms are correctly translated. And every time I correct them, I got outvoted by other people, who do not necessary live in Poland, nor speak Polish language...
The moral of this story: do not fully rely on CLDR. You still need to have local auditors/linguistic reviewers.
You can use DateTimeFormatterBuilder in Java 8. Following example returns localized date only pattern e.g. "d.M.yyyy".
String datePattern = DateTimeFormatterBuilder.getLocalizedDateTimePattern(
FormatStyle.SHORT, null, IsoChronology.INSTANCE,
Locale.GERMANY); // or whatever Locale
The following code will give you the pattern for the locale:
final String pattern1 = ((SimpleDateFormat) DateFormat.getDateInstance(DateFormat.SHORT, locale)).toPattern();
System.out.println(pattern1);
Java 8 provides some useful features out of the box for working with and formatting/parsing date and time, including handling locales. Here is a brief introduction.
Basic Patterns
In the simplest case to format/parse a date you would use the following code with a String pattern:
DateTimeFormatter.ofPattern("MM/dd/yyyy")
The standard is then to use this with the date object directly for formatting:
return LocalDate.now().format(DateTimeFormatter.ofPattern("MM/dd/yyyy"));
And then using the factory pattern to parse a date:
return LocalDate.parse(dateString, DateTimeFormatter.ofPattern("MM/dd/yyyy"));
The pattern itself has a large number of options that will cover the majority of usecases, a full rundown can be found at the javadoc location here.
Locales
Inclusion of a Locale is fairly simple, for the default locale you have the following options that can then be applied to the format/parse options demonstrated above:
DateTimeFormatter.ofLocalizedDate(dateStyle);
The 'dateStyle' above is a FormatStyle option Enum to represent the full, long, medium and short versions of the localized Date when working with the DateTimeFormatter. Using FormatStyle you also have the following options:
DateTimeFormatter.ofLocalizedTime(timeStyle);
DateTimeFormatter.ofLocalizedDateTime(dateTimeStyle);
DateTimeFormatter.ofLocalizedDateTime(dateTimeStyle, timeStyle);
The last option allows you to specify a different FormatStyle for the date and the time. If you are not working with the default Locale the return of each of the Localized methods can be adjusted using the .withLocale option e.g
DateTimeFormatter.ofLocalizedTime(timeStyle).withLocale(Locale.ENGLISH);
Alternatively the ofPattern has an overloaded version to specify the locale too
DateTimeFormatter.ofPattern("MM/dd/yyyy",Locale.ENGLISH);
I Need More!
DateTimeFormatter will meet the majority of use cases, however it is built on the DateTimeFormatterBuilder which provides a massive range of options to the user of the builder. Use DateTimeFormatter to start with and if you need these extensive formatting features fall back to the builder.
Please find in the below code which accepts the locale instance and returns the locale specific data format/pattern.
public static String getLocaleDatePattern(Locale locale) {
// Validating if Locale instance is null
if (locale == null || locale.getLanguage() == null) {
return "MM/dd/yyyy";
}
// Fetching the locale specific date pattern
String localeDatePattern = ((SimpleDateFormat) DateFormat.getDateInstance(
DateFormat.SHORT, locale)).toPattern();
// Validating if locale type is having language code for Chinese and country
// code for (Hong Kong) with Date Format as - yy'?'M'?'d'?'
if (locale.toString().equalsIgnoreCase("zh_hk")) {
// Expected application Date Format for Chinese (Hong Kong) locale type
return "yyyy'MM'dd";
}
// Replacing all d|m|y OR Gy with dd|MM|yyyy as per the locale date pattern
localeDatePattern = localeDatePattern.replaceAll("d{1,2}", "dd").replaceAll(
"M{1,2}", "MM").replaceAll("y{1,4}|Gy", "yyyy");
// Replacing all blank spaces in the locale date pattern
localeDatePattern = localeDatePattern.replace(" ", "");
// Validating the date pattern length to remove any extract characters
if (localeDatePattern.length() > 10) {
// Keeping the standard length as expected by the application
localeDatePattern = localeDatePattern.substring(0, 10);
}
return localeDatePattern;
}
Since it's just the locale information you're after, I think what you'll have to do is locate the file which the JVM (OpenJDK or Harmony) actually uses as input to the whole Locale thing and figure out how to parse it. Or just use another source on the web (surely there's a list somewhere). That'll save those poor translators.
You can try something like :
LocalDate fromCustomPattern = LocalDate.parse("20.01.2014", DateTimeFormatter.ofPattern("MM/dd/yy"))
Im not sure about what you want, but...
SimpleDateFormat example:
SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yy");
Date date = sdf.parse("12/31/10");
String str = sdf.format(new Date());
I have a localized date format. I want to retrieve just the year format in Java.
So if I am given mmddyyyy I would like to extract yyyy.
if I am given mmddyy, i would like to extract yy.
I cannot find a way to get that info using SimpleDateFormat, Date, Calendar etc. classes.
It's important to note that the concept of a "year format" only really applies to SimpleDateFormat. (In the default JDK, anyway.) More specifically, SimpleDateFormat is the only DateFormat implementation provided by the JDK that uses the concept of a "format string" that you can pull out a year format from; the other implementations use more opaque mappings from a Date to a String. For this reason, what you're asking for is only well-defined on the SimpleDateFormat class (again, among the DateFormat implementations available in the stock JDK).
If you're working with a SimpleDateFormat, though, you can just pull the year format out with regular expressions:
SimpleDateFormat df=(something);
final Pattern YEAR_PATTERN=Pattern.compile("^(?:[^y']+|'(?:[^']|'')*')*(y+)");
Matcher m=YEAR_PATTERN.matcher(df.toPattern());
String yearFormat=m.find() ? m.group(1) : null;
// If yearFormat!=null, then it contains the FIRST year format. Otherwise, there is no year format in this SimpleDateFormat.
The regular expression looks so strange because it has to ignore any y's that happen in "fancy" quoted parts of the date format string, like "'Today''s date is 'yyyy-MM-dd". Per the comment in the code above, note that this only pulls out the first year format. If you need to pull out multiple formats, you'll just need to use the Matcher a little differently:
SimpleDateFormat df=(something);
final Pattern YEAR_PATTERN=Pattern.compile("\\G(?:[^y']+|'(?:[^']|'')*')*(y+)");
Matcher m=YEAR_PATTERN.matcher(df.toPattern());
int count=0;
while(m.find()) {
String yearFormat=m.group(1);
// Here, yearFormat contains the count-th year format
count = count+1;
}
I convert two types of Strings to an ISO format using SimpleDateFormat for parsing and org.apache.commons.lang.time.DateFormatUtils for formatting (since they provide a ISO formatter out-of-the-box).The pattern Strings for parsing are M/d/y H:m and d.M.y H:m. A typical String to convert may look either like 4/14/2009 11:22 or 4.14.2009 11:22. I initialize the parsers as follows:
SimpleDateFormat SLASH = new SimpleDateFormat(PATTERN_S, Locale.getDefault());
SimpleDateFormat DOT = new SimpleDateFormat(PATTERN_D, Locale.getDefault());
I get the the formatter:
FastDateFormat isoFormatter = DateFormatUtils.ISO_DATETIME_TIME_ZONE_FORMAT
After creating a Date from the parsed String:
Date date = FORMAT_SLASH.parse(old);
it is formatted for output:
isoFormatter.format(date)
The strange thing is : when a String with slashes was converted, the output looks like 2009-04-14T11:42:00+01:00 (which is correct) but when a String with dots was converted, the output looks like 2010-02-14T11:42:00+02:00, shifting my timezone to somewhere between Finland and South Africa, the year to 2010 and the month to february
What is going wrong here and why?
EDIT : changed the output strings to match real output (damn you, cut-n-paste). The reason was the interchanged M and d in the pattern strings that I failed to notice. 14 seems to be a perfecty valid month - its next year's february and even non-lenient settings can't force the formatter to reject it. The timeshift issue is resolved and the reason for the TimeZone change is provided by Jim Garrison. Thanks Ahmad and Jim
Your dot pattern is d.M.y H:m while your example shows that you meant M.d.y H:m, I supposed this would throw a ParseException, but it doesn't and it causes timezone issues.