Java DateTimeFormatter throws an exception for when you try a date that goes outside of a possible range, for example:
DateTimeFormatter dtf = DateTimeFormatter.ofPattern("M/d/yyyy");
String dateString = "12/32/2015";
LocalDate ld = LocalDate.parse(dateString, dtf);
will throw:
Exception in thread "main" java.time.format.DateTimeParseException: Text '12/32/2015' could not be parsed: Invalid value for DayOfMonth (valid values 1 - 28/31): 32
But when I enter an invalid calendar date that is still syntactically possible by their standards, it autocorrects it to be a valid date, for example:
DateTimeFormatter dtf = DateTimeFormatter.ofPattern("M/d/yyyy");
String dateString = "2/31/2015";
LocalDate ld = LocalDate.parse(dateString, dtf);
it successfully parses but autocorrects to 2015-02-28. I don't want this behavior, I want it to still throw an exception when the date is not a valid calendar date. Is there a built-in option I can set for that to happen, or do I really have to try to manually sift out these instances?
You can use a STRICT resolver style:
import static java.time.format.ResolverStyle.STRICT;
DateTimeFormatter dtf = DateTimeFormatter.ofPattern("M/d/uuuu").withResolverStyle(STRICT);
By default, ofPattern uses a SMART resolver style which will use reasonable defaults.
Note that I have used uuuu instead of yyyy, i.e. YEAR instead of YEAR_OF_ERA. Assuming you are in a Gregorian calendar system, the two are equivalent for years in the current era (year 1 or greater). The difference is explained in more details in the links above.
Related
I have a problem parsing a String to LocalDate.
According to similar questions on Stackoverflow and documentation I am using the correct values dd (day of the month), MM (month of the year) and yyyy (year).
My String
String mydate = "18.10.2022 07:50:18";
My parsing test code
System.out.println(
LocalDate.parse(testPasswordExp)
.format(DateTimeFormatter.ofPattern("dd.MM.yyyy HH:mm:ss")
)
);
Error:
Caused by: java.lang.RuntimeException:
java.time.format.DateTimeParseException:
Text '18.10.2022 07:50:18' could not be parsed at index 0
The main problem of your code example is that you first parse the String to a LocalDate without the use of a suitable DateTimeFormatter and then format() it with a DateTimeFormatter that tries to format hour of day, minute of hour and second of minute which just aren't there in a LocalDate.
You can parse this String to a LocalDate directly, but better parse it to a LocalDateTime because your String contains more than just information about
day of month
month of year
year
Your myDate (and probably the testPasswordExp, too) has a time of day. You can get a LocalDate as the final result that way, too, because a LocalDateTime can be narrowed down toLocalDate().
A possible way:
public static void main(String[] args) {
// example datetime
String testPasswordExp = "18.10.2022 07:50:18";
System.out.println(
LocalDateTime // use a LocalDateTime and…
.parse( // … parse …
testPasswordExp, // … the datetime using a specific formatter,
DateTimeFormatter.ofPattern("dd.MM.uuuu HH:mm:ss")
).toLocalDate() // then extract the LocalDate
);
}
Output:
2022-10-18
You don't use the specified format for parsing, you use it to format the parsed date.
LocalDate.parse(mydate)
… uses the default ISO_LOCAL_DATE format. You are looking for this overload:
LocalDate.parse(mydate, DateTimeFormatter.ofPattern("dd.MM.yyyy HH:mm:ss"))
This method uses the specified format for parsing string to date. See this code run at Ideone.com.
Note that you are using LocalDate, meaning it will throw away the time part, keeping only the date after parsing. You probably meant to use LocalDateTime.
You can use
String mydate = "18.10.2022 07:50:18";
LocalDate ld = LocalDate.parse(mydate, DateTimeFormatter.ofPattern("dd.MM.yyyy HH:mm:ss"));
System.out.println(ld.toString());
I need to get the datetime of 1 year back considering the current datetime. The format needed to be in "yyyy-MM-dd HH:mm:ss.SSS"
ex : 2019-08-13 12:00:14.326
I tried following. But getting an error.
LocalDate now = LocalDate.now();
LocalDate localDate = LocalDate.parse(now.toString(), DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SSS")).minusYears(1);
Below Exception returned:
DateTimeParseException: Text '2020-08-13' could not be parsed
What's the best way to do this in Java 8+ ?
A LocalDate does not hold any information about hours, minutes, seconds or any unit below, instead, it holds information about year, month and day. By calling LocalDate.now() you are getting the date of today (the day of code execution).
If you need the time as well, use a LocalDateTime, which has a method now(), too, and actually consists of a LocalDate and a LocalTime.
Your error message tells you that the content of a LocalDate cannot be formatted using the given pattern (-String) "yyyy-MM-dd HH:mm:ss.SSS" because that pattern requires values for hours (HH), minutes (mm), seconds (ss) and milliseconds (SSS are fraction of seconds and three of them make it be milliseconds).
For parsing Strings or formatting datetimes, a LocalDateTime may be suitable but if you want to reliably add or subtract a year or any other amount of time, you'd rather use a class that considers time zones, offsets and daylight saving like ZonedDateTime or OffsetDateTime...
The LocalDate is the wrong class for your requirement as it does not hold the time information. You can use LocalDateTime but I suggest you use OffsetDateTime or ZonedDateTime so that you can get the flexibility of using the Zone Offset and Zone ID. Check https://docs.oracle.com/javase/tutorial/datetime/iso/overview.html for an overview of date-time classes.
Also, keep in mind that a date or time or date-time object is an object that just holds the information about date/time; it doesn't hold any information about formatting and therefore no matter what you do when you print their objects, you will always get the output what their toString() methods return. In order to format these classes or in other words, to get a string representing a custom format of these objects, you have formatting API (e.g. the modern DateTimeFormatter or legacy SimpleDateFormat) at your disposal.
A sample code:
import java.time.OffsetDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;
public class Main {
public static void main(String[] args) {
// Get the current date & time at UTC
OffsetDateTime odtNow = OffsetDateTime.now(ZoneOffset.UTC);
System.out.println("Now at UTC: " + odtNow);
// Get the date & time one year ago from now at UTC
OffsetDateTime odtOneYearAgo = odtNow.minusYears(1);
System.out.println("One year ago at UTC: " + odtNow);
// Define a formatter for the output in the desired pattern
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SSS");
// Format the date & time using your defined formatter
String formattedDateTimeOneYearAgo = formatter.format(odtOneYearAgo);
System.out.println("Date Time in the pattern, yyyy-MM-dd HH:mm:ss.SSS: " + formattedDateTimeOneYearAgo);
}
}
Output:
Now at UTC: 2020-08-13T08:50:36.277895Z
One year ago at UTC: 2020-08-13T08:50:36.277895Z
Date Time in the pattern, yyyy-MM-dd HH:mm:ss.SSS: 2019-08-13 08:50:36.277
May not be the best way, but this will do it
LocalDateTime date = LocalDateTime.now().minusYears(1);
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SSS");
System.out.println(date.format(formatter));
You say you want date+time from 1 year back, but you give it only a date (LocalDate). If you just want the date, all you need to do is:
LocalDate now = LocalDate.now();
LocalDate then = now.minusYears(1);
And if you want the timestamp also, then:
LocalDateTime now = LocalDateTime.now();
LocalDateTime then = now.minusYears(1);
And so on for other objects.
As mentioned you should use LocalDateTime instead of LocalDate.
Your exception was thrown because your input String is in ISO_DATE_TIME format
Java Doc
DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SSS");
String now = dateTimeFormatter.format(LocalDateTime.now());
LocalDateTime localDate = LocalDateTime.parse(now, dateTimeFormatter);
I'm trying to parse a datetime coming from a European RSS feed. The date looks like this: "06.03.2018 06:00 CET". I want a ZonedDateTime or OffsetDateTime, but I can't convince Java to parse the String. What am I doing wrong?
DateTimeFormatter dtf = DateTimeFormatter.ofPattern("dd.MM.YYYY HH:mm z");
ZonedDateTime zdt = ZonedDateTime.parse("06.03.2018 06:00 CET", dtf);
Caused by: java.time.DateTimeException: Unable to obtain ZonedDateTime from TemporalAccessor: {WeekBasedYear[WeekFields[SUNDAY,1]]=2018, MonthOfYear=3, DayOfMonth=6},ISO,Europe/Paris resolved to 06:00 of type java.time.format.Parsed
// seems to be crashing here: LocalDate.java:363
public static LocalDate from(TemporalAccessor temporal) {
Objects.requireNonNull(temporal, "temporal");
LocalDate date = temporal.query(TemporalQueries.localDate());
if (date == null) { // <== SOMEHOW THIS IS NULL
throw new DateTimeException("Unable to obtain LocalDate from TemporalAccessor: " +
temporal + " of type " + temporal.getClass().getName());
}
return date;
}
The value of temporal is:
{WeekBasedYear[WeekFields[SUNDAY,1]]=2018, MonthOfYear=3, DayOfMonth=6},ISO,Europe/Paris resolved to 06:00
Uppercase Y represents the week-based year (see here for a detailed explanation), while the year field is represented by lowercase y. See the javadoc for details:
https://docs.oracle.com/javase/8/docs/api/java/time/format/DateTimeFormatter.html#patterns
So change your pattern to "dd.MM.yyyy HH:mm z".
Another detail is that timezone abbreviations are ambiguous. CET is used by more than one country, hence it can be mapped to multiple timezones: https://www.timeanddate.com/time/zones/cet#tz-where
Some abbreviations might work (aka "doesn't throw exception"), but they'll be mapped to some arbitrary default that you don't have control over. In my JVM, running this code:
DateTimeFormatter dtf = DateTimeFormatter.ofPattern("dd.MM.yyyy HH:mm z");
ZonedDateTime zdt = ZonedDateTime.parse("06.03.2018 06:00 CET", dtf);
Produces a ZonedDateTime equals to:
2018-03-06T06:00+01:00[Europe/Paris]
CET was mapped to "Europe/Paris" (which is some arbitrary choice of the JVM, but it's not a guarantee that you'll always get that). And CET is also used by many others timezones, such as "Europe/Berlin", "Europe/Madrid" and many others.
If you want to control exactly what timezone you want when there's an abbreviation, you can create a set with your choices and use a DateTimeFormatterBuilder to create your DateTimeFormatter:
// set of preferred zones
Set<ZoneId> preferredZones = new HashSet<ZoneId>();
// my arbitrary choice for CET
preferredZones.add(ZoneId.of("Europe/Berlin"));
DateTimeFormatter dtf = new DateTimeFormatterBuilder()
// date/time
.appendPattern("dd.MM.yyyy HH:mm ")
// zone names
.appendZoneText(TextStyle.SHORT, preferredZones)
// create formatter
.toFormatter(Locale.US);
ZonedDateTime zdt = ZonedDateTime.parse("06.03.2018 06:00 CET", dtf);
Now the ZonedDateTime will be set to the timezone I've chosen in my set of preferred zones:
2018-03-06T06:00+01:00[Europe/Berlin]
Is there any way to use the following simpleDateFormat:
final SimpleDateFormat simpleDateFormatHour = new SimpleDateFormat("HH:mm:ss z");
and when invoking:
simpleDateFormat.parse("12:32:21 JST");
to return current date on the Date object?
For these example, it will return:
Thu Jan 01 05:32:21 EET 1970
and not:
<<today>> 05:32:21 EET <<currentYear>>
as I need.
No, SimpleDateFormat needs explicity the date in the input string. If you're using Java 8, you can go with a LocalDateTime:
LocalDateTime localDateTime = LocalDate.now().atTime(5, 32, 21);
If you want to include a time-zone, you can use ZonedDateTime.
Construct another SimpleDateFormat to print today's date:
String today = new SimpleDateFormat("yyyy/MM/dd").print(new Date());
(Be careful here: you might want to set the time zone on the SimpleDateFormat, as "today" is different in different time zones).
Update the date format to include year, month and day:
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss z");
And then prepend the date string with the date you want:
simpleDateFormat.parse(today + " " + "12:32:21 JST");
A better solution using flexible default values (today instead of 1970-01-01) would be in Java-8 with the new built-in date-time-library located in package java.time:
String input = "12:32:21 JST";
String pattern = "HH:mm:ss z";
LocalDate today = LocalDate.now(ZoneId.of("Asia/Tokyo"));
DateTimeFormatter dtf =
new DateTimeFormatterBuilder().parseDefaulting(ChronoField.YEAR, today.getYear())
.parseDefaulting(ChronoField.MONTH_OF_YEAR, today.getMonthValue()).parseDefaulting(
ChronoField.DAY_OF_MONTH,
today.getDayOfMonth()
).appendPattern(pattern).toFormatter(Locale.ENGLISH);
ZonedDateTime zdt = ZonedDateTime.parse(input, dtf);
System.out.println(zdt); // 2016-12-23T12:32:21+09:00[Asia/Tokyo]
However, I still see a small bug related to the fact that this code makes a hardwired assumption about the used zone BEFORE parsing the real zone so please handle with care. Keep in mind that the current date depends on the zone. But maybe you only need to handle a scenario where just the Japan time is used by users.
Hint: You can also parse in two steps. First step with any kind of fixed default date in order to get the zone information of the text to be parsed. And then you can use this zone information for suggested solution above. An awkward but safe procedure.
You can use this code if you want to change only the year and the day
final SimpleDateFormat simpleDateFormatHour = new SimpleDateFormat("HH:mm:ss z");
Date date = simpleDateFormatHour.parse("12:32:21 JST");
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
calendar.set(Calendar.YEAR, Calendar.getInstance().get(Calendar.YEAR));
calendar.set(Calendar.DAY_OF_YEAR, Calendar.getInstance().get(Calendar.DAY_OF_YEAR));
date = calendar.getTime();
I am simply trying to convert a date string into a DateTime object in Java 8. Upon running the following lines:
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyyMMdd");
LocalDateTime dt = LocalDateTime.parse("20140218", formatter);
I get the following error:
Exception in thread "main" java.time.format.DateTimeParseException:
Text '20140218' could not be parsed:
Unable to obtain LocalDateTime from TemporalAccessor:
{},ISO resolved to 2014-02-18 of type java.time.format.Parsed
at java.time.format.DateTimeFormatter.createError(DateTimeFormatter.java:1918)
at java.time.format.DateTimeFormatter.parse(DateTimeFormatter.java:1853)
at java.time.LocalDateTime.parse(LocalDateTime.java:492)
The syntax is identical to what has been suggested here, yet I am served with an exception. I am using JDK-8u25.
It turns out Java does not accept a bare Date value as DateTime. Using LocalDate instead of LocalDateTime solves the issue:
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyyMMdd");
LocalDate dt = LocalDate.parse("20140218", formatter);
If you really need to transform a date to a LocalDateTime object, you could use the LocalDate.atStartOfDay(). This will give you a LocalDateTime object at the specified date, having the hour, minute and second fields set to 0:
final DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyyMMdd");
LocalDateTime time = LocalDate.parse("20140218", formatter).atStartOfDay();
For what is worth if anyone should read again this topic(like me) the correct answer would be in DateTimeFormatter definition, e.g.:
private static DateTimeFormatter DATE_FORMAT =
new DateTimeFormatterBuilder().appendPattern("dd/MM/yyyy[ [HH][:mm][:ss][.SSS]]")
.parseDefaulting(ChronoField.HOUR_OF_DAY, 0)
.parseDefaulting(ChronoField.MINUTE_OF_HOUR, 0)
.parseDefaulting(ChronoField.SECOND_OF_MINUTE, 0)
.toFormatter();
One should set the optional fields if they will appear. And the rest of code should be exactly the same.
Edit : usefull thing from wittyameta comment :
Remember to add the parseDefaulting AFTER you have called appendPattern. Otherwise it'll give DateTimeParseException
For anyone who landed here with this error, like I did:
Unable to obtain LocalDateTime from TemporalAccessor: {HourOfAmPm=0, MinuteOfHour=0}
It came from a the following line:
LocalDateTime.parse(date, DateTimeFormatter.ofPattern("M/d/yy h:mm"));
It turned out that it was because I was using a 12hr Hour pattern on a 0 hour, instead of a 24hr pattern.
Changing the hour to 24hr pattern by using a capital H fixes it:
LocalDateTime.parse(date, DateTimeFormatter.ofPattern("M/d/yy H:mm"));
This is a really unclear and unhelpful error message. After much trial and error I found that LocalDateTime will give the above error if you do not attempt to parse a time. By using LocalDate instead, it works without erroring.
This is poorly documented and the related exception is very unhelpful.
Expanding on retrography's answer..: I had this same problem even when using LocalDate and not LocalDateTime. The issue was that I had created my DateTimeFormatter using .withResolverStyle(ResolverStyle.STRICT);, so I had to use date pattern uuuuMMdd instead of yyyyMMdd (i.e. "year" instead of "year-of-era")!
DateTimeFormatter formatter = new DateTimeFormatterBuilder()
.parseStrict()
.appendPattern("uuuuMMdd")
.toFormatter()
.withResolverStyle(ResolverStyle.STRICT);
LocalDate dt = LocalDate.parse("20140218", formatter);
(This solution was originally a comment to retrography's answer, but I was encouraged to post it as a stand-alone answer because it apparently works really well for many people.)
If the date String does not include any value for hours, minutes and etc you cannot directly convert this to a LocalDateTime. You can only convert it to a LocalDate, because the string only represent the year,month and date components it would be the correct thing to do.
DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyyMMdd");
LocalDate ld = LocalDate.parse("20180306", dtf); // 2018-03-06
Anyway you can convert this to LocalDateTime.
DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyyMMdd");
LocalDate ld = LocalDate.parse("20180306", dtf);
LocalDateTime ldt = LocalDateTime.of(ld, LocalTime.of(0,0)); // 2018-03-06T00:00
You do not need to define a DateTimeFormatter
You do not need to define a DateTimeFormatter to parse the given date string. You can use the OOTB (Out-Of-The-Box), DateTimeFormatter.BASIC_ISO_DATE to parse it.
Demo:
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.format.DateTimeFormatter;
public class Main {
public static void main(String[] args) {
LocalDate date = LocalDate.parse("20140218", DateTimeFormatter.BASIC_ISO_DATE);
System.out.println(date);
// In case you need an instance of LocalDateTime
LocalDateTime ldt = date.atTime(LocalTime.MIN);
System.out.println(ldt);
}
}
Output:
2014-02-18
2014-02-18T00:00
ONLINE DEMO
Learn more about the modern Date-Time API* from Trail: Date Time.
* If you are working for an Android project and your Android API level is still not compliant with Java-8, check Java 8+ APIs available through desugaring. Note that Android 8.0 Oreo already provides support for java.time. Check this answer and this answer to learn how to use java.time API with JDBC.
DateTimeFormatter format = new DateTimeFormatterBuilder()
.appendPattern("yyyy-MM-dd")
.parseDefaulting(ChronoField.HOUR_OF_DAY, 0)
.parseDefaulting(ChronoField.MINUTE_OF_HOUR, 0)
.parseDefaulting(ChronoField.SECOND_OF_MINUTE, 0)
.parseDefaulting(ChronoField.MILLI_OF_SECOND, 0)
.toFormatter();
Works for me
In cases where you simply want to take a format (whether or not it has time) and want to parse to a LocalDateTime, you can do the following.
LocalDateTime parseDateTime(String dateTime, DateTimeFormatter fmt) {
return fmt.parse(dateTime, t -> {
LocalDate date = t.query(TemporalQueries.localDate());
LocalTime time = t.query(TemporalQueries.localTime());
return LocalDateTime.of(date, time != null ? time : LocalTime.MIDNIGHT);
});
}
I needed this because I was getting the date/time pattern as a parameter for a custom Spark UDF.
This works fine
public class DateDemo {
public static void main(String[] args) {
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd-MM-yyyy hh:mm");
String date = "16-08-2018 12:10";
LocalDate localDate = LocalDate.parse(date, formatter);
System.out.println("VALUE="+localDate);
DateTimeFormatter formatter1 = DateTimeFormatter.ofPattern("dd-MM-yyyy HH:mm");
LocalDateTime parse = LocalDateTime.parse(date, formatter1);
System.out.println("VALUE1="+parse);
}
}
output:
VALUE=2018-08-16
VALUE1=2018-08-16T12:10
Try this one:
DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("MM-dd-yyyy");
LocalDate fromLocalDate = LocalDate.parse(fromdstrong textate, dateTimeFormatter);
You can add any format you want. That works for me!
I arrived at this problem because my input string didn't have a year in it:
input string: Tuesday, June 8 at 10:00 PM
formatter: DateTimeFormatter.ofPattern("EEEE, MMMM d 'at' h:mm a", Locale.US);
I knew the year so I just appended it to get:
input string: Tuesday, June 8 at 6:30 PM 2021
formatter: DateTimeFormatter.ofPattern("EEEE, MMMM d 'at' h:mm a uuuu", Locale.US);