tl;dr
java.time.format.DateTimeFormatterBuilder::parseDefaulting
java.time
The DateTimeFormatter
class parses strings into date-time objects.
You can create customized instances of DateTimeFormatter
by using the DateTimeFormatterBuilder
class. That builder class enables you to specify default values for missing components of the input string.
DateTimeFormatter f =
new DateTimeFormatterBuilder()
.appendPattern( "MM-dd" )
.parseDefaulting(
ChronoField.YEAR ,
ZonedDateTime.now( ZoneId.of( "America/Montreal" ) ).getYear()
)
.toFormatter() ;
String input = "01-23" ;
LocalDate ld = LocalDate.parse( input , f ) ;
System.out.println( ld ) ;
ld.toString(): 2018-01-23
See also DateTimeFormatterBuilder with specified parseDefaulting conflicts for YEAR field.
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.
You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.*
classes.
Where to obtain the java.time classes?
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.