I have two timestamps represented as Strings in the same format, one fails and one succeeds, and I can't understand why. Any help is greatly appreciated. Here are the two values and below my test 2021-08-29 03:53.44.56738
2021-08-29 03:52:45.67890

Here's the error java.time.format.DateTimeParseException: Text '2021-08-29 03:53.44.56738' could not be parsed at index 16

    private static final int START_OF_MONTH = 1;

    private final static DateTimeFormatter DEFAULT_TIMESTAMP_FORMATTER = new DateTimeFormatterBuilder()
            .appendPattern("yyyy-MM-dd HH:mm:ss")
            .appendFraction(ChronoField.MICRO_OF_SECOND, 0, 6, true)// min 0 max 6
            .toFormatter();

    @Test
    public void test() throws Exception {

        System.out.println(process());
    }

    public Object process() throws Exception {

        // fails
        final String text = "2021-08-29 03:53.44.56738";
        // succeeds
        // final String text = "2021-08-29 03:52:45.67890";

        final String lowerCase = text.toLowerCase();
        final TemporalAccessor ta = DEFAULT_TIMESTAMP_FORMATTER.parse(lowerCase);
        if (ta.isSupported(ChronoField.HOUR_OF_DAY)) {
            return Timestamp.valueOf(LocalDateTime.from(ta));
        } else if (ta.isSupported(ChronoField.DAY_OF_MONTH)) {
            return Timestamp.valueOf(LocalDate.from(ta).atStartOfDay());
        } else if (ta.isSupported(ChronoField.MONTH_OF_YEAR)) {
            return Timestamp.valueOf(YearMonth.from(ta).atDay(START_OF_MONTH).atStartOfDay());
        } else {
            throw new IllegalArgumentException(String.format("[%s] is not a supported date format", lowerCase));
        }
    }

}

CodePudding user response：

If you catch your exception and print the message, you'll see that the problem is at index 16 of your string:

java.time.format.DateTimeParseException: Text '2021-08-29 03:53.44.56738' could not be parsed at index 16

If you look at index 16, you'll see there is a period instead of a colon after the minutes and before the seconds.

HH:mm:ss

03:53.44