how to convert String ("1-DEC-16") and ("01-DEC-16") to java Date as 01-DEC-2016

Question

I have CSV data to import into data base where I have date column in that CSV in that some dates are like 1-DEC-16 without a leading zero (padding zero). How to make that String as 01-DEC-2016? Can it be done with SimpleDateFormat or is there any String format method? I tried with below but it’s not happening.

String d="1-DEC-17";

String newstring = new SimpleDateFormat("yyyy-MM-dd").format(d);
System.out.println(newstring);

Possible duplicate of [Java string to date conversion](https://stackoverflow.com/questions/4216745/java-string-to-date-conversion) — Tom, Jun 06 '17 at 07:41
Possible duplicate of [How can I change the date format in Java?](https://stackoverflow.com/questions/3469507/how-can-i-change-the-date-format-in-java) — SomeJavaGuy, Jun 06 '17 at 07:41
even that SimpleDateFormat#format(d); takes an object as parameter, the operation is invalid with strings.... — ΦXocę 웃 Пepeúpa ツ, Jun 06 '17 at 07:43
A `SimpleDateFormat` can convert a `String` to a `Date` or a `Date` to a `String`, but you shouldn't use it to convert a `String` to a `String`. — Dawood ibn Kareem, Jun 06 '17 at 07:44
ok thank you for the info, i want convert 1-Dec-16 to java date as 01-DEC-2017 how to give formate? — bharathRaj, Jun 06 '17 at 08:15
@bharathRaj Is the Shift key broken on your keyboard? I cleaned that up for you on this Question, while adding some other text for search optimization. But try to get that key fixed soon. — Basil Bourque, Jun 06 '17 at 08:28

Basil Bourque · Answer 1 · 2017-06-06T08:25:51.050

`d` vs `dd`

To parse a string with a leading zero on the month or day-of-month, use a pair of formatting pattern characters. That would be dd for day-of-month.

To parse a string without a leading zero, use a single character, d for day-of-month.

Unfortunately, your input has the month name abbreviation in all uppercase. That violates the norm of the English-speaking locales I know of, such as Locale.US. So by default, a DateTimeFormatter will refuse to process that improper input. To tolerate the all-uppercase, we can set the formatter to be “lenient”.

DateTimeFormatter f = DateTimeFormatter.ofPattern( "d-MMM-uu" , Locale.US ).withResolverStyle( ResolverStyle.LENIENT )  ;
LocalDate ld = LocalDate.parse( "1-DEC-17" , f ) ;

See this code run live at IdeOne.com.

ld.toString(): 2017-12-01

If sending this value to a database, do not use a string for date-time value. Use a date-time object for date-time values.

For JDBC drivers compliant with JDBC 4.2 and later, pass the java.time types directly via setObject & getObject.

myPreparedStatement.setObject( … , ld ) ;

If not compliant, convert briefly to the troublesome old legacy type, java.sql.Date. Use the new methods added to the old classes.

java.sql.Date d = java.sql.Date.valueOf( ld ) ;
myPreparedStatement.setDate( … , d ) ;

About java.time

The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

Where to obtain the java.time classes?

Java SE 8, Java SE 9, and later
- Built-in.
- Part of the standard Java API with a bundled implementation.
- Java 9 adds some minor features and fixes.
Java SE 6 and Java SE 7
- Much of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
Android
- The ThreeTenABP project adapts ThreeTen-Backport (mentioned above) for Android specifically.
- See How to use ThreeTenABP….

The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.

how to convert String ("1-DEC-16") and ("01-DEC-16") to java Date as 01-DEC-2016

1 Answers1

d vs dd

About java.time

`d` vs `dd`