How to put .min() or .max() as method parameter for a stream?

DerBenniAusA :

How can I pass the .min() or .max() expression as a method parameter in a code like this:

Given code:

private LocalDate getMaxDate() {
    LocalDate maxdate = dates.stream()
              .max( Comparator.comparing( LocalDate::toEpochDay ) )
              .get();
}

private LocalDate getMinDate() {
    LocalDate maxdate = dates.stream()
              .min( Comparator.comparing( LocalDate::toEpochDay ) )
              .get();
}

Code that I expect to have:

private LocalDate getDate(SomeType _EXPR_){
        LocalDate maxdate = dates.stream()
                  ._EXPR_( Comparator.comparing( LocalDate::toEpochDay ) )
                  .get();
    }

Hint: _EXPR_ shall be .min(), sometimes .max()

Andrew Tobilko :

The method is

private LocalDate getDate(Function<Comparator<LocalDate>, BinaryOperator<LocalDate>> f) {
  return dates.stream()
              .reduce(f.apply(Comparator.comparing(LocalDate::toEpochDay)))
              .get();
}

To call it, use

getDate(BinaryOperator::maxBy);
getDate(BinaryOperator::minBy);

Beware of NoSuchElementException which Optional#get may throw.