converting date format

Question

I got date as \'14-Dec-2010\' i want to get the month in number format for the given date. that is., i want to convert the date to \'14-12-2010\'.<

Answer 1

Avoid using the troublesome old date-time classes bundled with the earliest versions of Java. They are poorly designed and confusing.

java.time

The old classes are supplanted by the java.time framework.

For a date-only value without time of day and without time zone use LocalDate class.

Parse the String input using DateTimeFormatter.

String input = "14-Dec-2010";

DateTimeFormatter formatter = DateTimeFormatter.ofPattern( "dd-MMM-yyyy" );
LocalDate localDate = LocalDate.parse( input , formatter );

To generate a String in another format, define another formatter.

DateTimeFormatter formatter2 = DateTimeFormatter.ofPattern( "dd-MM-yyyy" );
String output = localDate.format( formatter2 );

Better yet, let DateTimeFormatter automatically localize.

Locale l = Locale.CANADA_FRENCH ;  // Or Locale.US, Locale.ITALY, etc.
DateTimeFormatter f = DateTimeFormatter.ofLocalizedDate( FormatStyle.SHORT ).withLocale( l );
String output = localDate.format( f );  // Generates String in a localized format.

SQL

For SQL just pass objects, do not use strings. Pass LocalDate via setObject on a PreparedStatement if your JDBC driver complies with the JDBC 4.2 spec.

myPrepStmt.setObject( localDate );

If not, fall back to the old java.sql.Date class by using new conversion methods added to the old classes.

java.sql.Date sqlDate = java.sql.Date.from( localDate );
myPrepStmt.setDate( sqlDate );