I have just upgraded Java from JDK-15 to JDK-16 and I see a problem while converting Date
using SimpleDateFormat
. September month alone while formatted using yyyy-MMM-dd
is giving 4 characters instead of 3.
Eg: 2021-Sep-11
is being shown as 2021-Sept-11
Calendar cal = Calendar.getInstance();
cal.add(Calendar.DATE, 150);
SimpleDateFormat format1 = new SimpleDateFormat("yyyy-MMM-dd");
System.out.println(cal.getTime());
String formatted = format1.format(cal.getTime());
System.out.println(formatted);
Looks like a bug to me. I can't see any update to this in the release notes. Anyone facing similar issue? Was working alright till JDK-15.
Never use Date-Time formatting/parsing type without Locale
because the texts are Locale
-sensitive.
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Locale;
public class Main {
public static void main(String[] args) {
Calendar cal = Calendar.getInstance();
cal.add(Calendar.DATE, 150);
SimpleDateFormat format1 = new SimpleDateFormat("yyyy-MMM-dd", Locale.ENGLISH);
System.out.println(cal.getTime());
String formatted = format1.format(cal.getTime());
System.out.println(formatted);
}
}
Output:
2021-Sep-11
Note that the java.util
date-time API and their formatting API, SimpleDateFormat
are outdated and error-prone. It is recommended to stop using them completely and switch to java.time
, the modern date-time API* .
Using modern date-time API:
import java.time.LocalDate;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.util.Locale;
public class Main {
public static void main(String[] args) {
// Change ZoneId as per your requirement e.g. ZoneId.of("Europe/London")
LocalDate date = LocalDate.now(ZoneId.systemDefault());
date = date.plusDays(150);
DateTimeFormatter dtf = DateTimeFormatter.ofPattern("uuuu-MMM-dd", Locale.ENGLISH);
String formatted = dtf.format(date);
System.out.println(formatted);
}
}
Output:
2021-Sep-11
Check this answer to learn more about u
vs y
.
Learn more about the modern date-time API from Trail: Date Time.
* For any reason, if you have to stick to Java 6 or Java 7, you can use ThreeTen-Backport which backports most of the java.time functionality to Java 6 & 7. 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 and How to use ThreeTenABP in Android Project.