Java: DateTimeFormatter fail to parse time string when seconds and milliseconds are all 0s?

Question

Basically, I am using the following code to parse string as LocalDateTime, which works fine most of the time.

DateTimeFormatter dtformatter = DateTimeFormat         


        

Answer 1

I'm not sure why it's not work, it seems it is a bug because when I use :

20180301091600001        result is      2018-03-01T09:16:00.001
----------------^                       -----------------^^^^^^

Also another test :

2018030100000000         result is      2018-03-01T00:00
--------^^^-----                        -----------^^^^^^^^^^^

It seems that the parser ignore the seconds and millisecond when it is zero, why?

The full explanation why?, is in the answer of Basil Bourque.

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Solution

Here is a quick fix where you can use another formatter like this :

var result = LocalDateTime.parse("20180301091600000", dtformatter)
                .format(DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss:SSS"));

Output

2018-03-01T09:16:00:000