Java DateTimeFormatterBuilder with optional pattern results in DateTimeParseException

Question

Goal

Provide a flexible parser for LocalDate instances that can handle input in one of the following formats:

• yyyy
• yyyyMM
• yyyyMMdd<

Answer 1

In this part of the code you already set a value for month and day .parseDefaulting(ChronoField.MONTH_OF_YEAR, 1) .parseDefaulting(ChronoField.DAY_OF_MONTH, 1) Then you're trying to pass an input for month and year in your code System.out.println(parser.parse("201411", LocalDate::from)); That you already set.