CODEWITHSUNDEEP
javaarraylistjava-streamjava-time
kaviya .P
kaviya .P

Reputation: 479

Unable to get the initial date of the month using withDayOfMonth

I want to get the first datetime of the month for the given date-time as follows: For the date 19-04-2018 19:00:00 (dd-MM-yyyy HH:mm:ss) it should be 01-04-2018 00:00:00.

I have tried the below code, but it gives the empty list.

startDate may contains the value like 01-04-2018 00:00:00.

List<scPosR> scPosRListPerStoreAndTimeStamp =  spst.stream().filter(
                scPosR -> Timestamp.valueOf(scPosR.getTransactionDate()
                        .toLocalDateTime()
                        .toLocalDate()
                        .withDayOfMonth(1)
                        .atStartOfDay())
                .equals(startDate))
        .collect(Collectors.toList());

Can anyone please suggest me to do it?

Upvotes: 0

Views: 124

Answers (1)

Anonymous
Anonymous

Reputation: 86324

I cannot tell what went wrong. Like Pavan observed, your code works as expected also on my computer and returns a list containing the objects with a transaction date in April. One possible explanation is if your startDate variable doesn’t hold a Timestamp, but some other (runtime) type. Another possible explanation is a timezone issue: if your startDate timestamp was created in a different time zone, it won’t be equal to the timestamps created in your stream filter.

Anyway here’s a simpler version of your code hoping it will also be simpler to debug.

    YearMonth month = YearMonth.of(2018, Month.APRIL);

    List<ScPosR> scPosRListPerStoreAndTimeStamp =  spst.stream()
            .filter(scPosR -> YearMonth.from(scPosR.getTransactionDate().toLocalDateTime())
                    .equals(month))
            .collect(Collectors.toList());

Still better if you could get completely rid of the outdated Timestamp class, of course.

Upvotes: 1

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