How to parse an ISO date with LocalDateTime.parse(...)

Question

I want to parse a date string like 2011-11-30 like this:

LocalDateTime.parse("2011-11-30", DateTimeFormatter.ISO_LOCAL_DATE)

But I get the following exception:

java.time.format.DateTimeParseException: Text '2011-11-30' could not be parsed:
Unable to obtain LocalDateTime from TemporalAccessor

If I pass a date and time string everything works as expected:

LocalDateTime.parse("2011-11-30T23:59:59", DateTimeFormatter.ISO_LOCAL_DATE_TIME)

How can I parse a date like 2011-11-30 to a LocalDateTime (with a default time)?

Answer 1

As @JB Nizet suggested, the following works

LocalDate localDate = LocalDate.parse("2011-11-30", DateTimeFormatter.ISO_LOCAL_DATE);
LocalDateTime localDateTime = localDate.atTime(23, 59, 59);
System.out.println(localDateTime); // 2011-11-30T23:59:59

How can I parse a date like 2011-11-30 to a LocalDateTime (with a default time)?

1. Parse it first in a LocalDate
2. Use LocalDateTime atTime() method to set your default time

Note: Use of DateTimeFormatter.ISO_LOCAL_DATE is superfluous for parse(), see API LocalDate#parse()

Answer 2

The sample below use some magic numbers, wich should be avoid (What is a magic number, and why is it bad?).

Instead of using the method atTime(hour, minute, second),

    LocalDate localDate = LocalDate.parse("2011-11-30", DateTimeFormatter.ISO_LOCAL_DATE);
    LocalDateTime localDateTime = localDate.atTime(23, 59, 59);

you can use the LocalTime constants, such as LocalTime.MAX, (23:59:59), LocalTime.MIN (00:00:00), LocalTime.MIDNIGHT (23:59:59) or LocalTime.NOON (12:00:00)

    LocalDate localDate = LocalDate.parse("2011-11-30", DateTimeFormatter.ISO_LOCAL_DATE);
    LocalDateTime localDateTime = LocalDateTime.of(localDate, LocalTime.MIN);

It is better for maintainability and cross-reference.