How do I parse an ISO-8601 formatted string that contains no punctuation in Java 8?

looks like a known issue...

bug_id=JDK-8031085 bug_id=JDK-8138676

Workaround:

DateTimeFormatter dtf = new DateTimeFormatterBuilder().appendPattern("yyyyMMddHHmmss").appendValue(ChronoField.MILLI_OF_SECOND, 3).toFormatter()

or

CUSTOMER SUBMITTED WORKAROUND : use the following format (mind the '.'): "yyyyMMddHHmmss.SSS"

LocalDateTime.parse("20150910121314987", DateTimeFormatter.ofPattern("yyyyMMddHHmmss.SSS"))

or alternatively use jodatime library