For a Date object, the solution may rely on a Calendar instance. The code that is bundled to this book contains this solution.

For JDK 8 classes, Java provides dedicated getFoo() methods and a  get​(TemporalField field) method. For example, let's assume the following LocalDateTime object:

LocalDateTime ldt = LocalDateTime.now();

Relying on getFoo() methods, we get the following code:

int year = ldt.getYear();
int month = ldt.getMonthValue();
int day = ldt.getDayOfMonth();
int hour = ldt.getHour();
int minute = ldt.getMinute();
int second = ldt.getSecond();
int nano = ldt.getNano();

Or, relying on get​(TemporalField field) results in the following:

int yearLDT = ldt.get(ChronoField.YEAR);
int monthLDT = ldt.get(ChronoField.MONTH_OF_YEAR);
int dayLDT = ldt.get(ChronoField.DAY_OF_MONTH);
int hourLDT = ldt.get(ChronoField.HOUR_OF_DAY);
int minuteLDT = ldt.get(ChronoField.MINUTE_OF_HOUR);
int secondLDT = ldt.get(ChronoField.SECOND_OF_MINUTE);
int nanoLDT = ldt.get(ChronoField.NANO_OF_SECOND);

Notice that the months are counted from one, which is January.

For example, a LocalDateTime object of 2019-02-25T12:58:13.109389100 can be cut into date-time units, resulting in the following:

Year: 2019 Month: 2 Day: 25 Hour: 12 Minute: 58 Second: 13 Nano: 109389100

With a little intuition and documentation, it is very easy to adapt this example for LocalDate, LocalTime, ZonedDateTime, and others.