How to find the total number of days in the month using LocalDateTime in Java 8?

[hasnainahmad]

I am using java 8 date and time classes in my code. I can find year, month, day, hours, minutes and seconds, but I cannot find a method to find a number of days in a month.

Here is my code.

String oldestDateString = "2015-10-01 00:00:00";
String latestDateString = "2015-12-25 00:00:00";

DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
LocalDateTime oldestDate = LocalDateTime.parse(oldestDateString, formatter);
LocalDateTime latestDate = LocalDateTime.parse(latestDateString, formatter);
   
int year = oldestDate.getYear();
int month = oldestDate.getMonthValue();
int day = oldestDate.getDayOfMonth();
int hours = oldestDate.getHour();
int minutes = oldestDate.getMinute();
int seconds = oldestDate.getSecond();

I also want to iterate through “oldestDate” to “latestDate”. How can I iterate through “oldestDate” to “latestDate” until the “oldestDate” reaches to “latestDate”?

[chaarmann]

Well, I am not up-to-date with the latest java date-time libraries, as I am with GregorianCalend ar and Joda-Time, but I can tell you a general trick that works independent of any library.
Number of days in February 2000:

1. get date object for 1st March 2000.
2. subtract one day.
3. get the day of the resulting date.

About your second question:
iterate by using a for-loop starting with oldestDate and add one day in each step until you reach your latestDate.