Task03Main.java

package com.example.task03;

import java.util.Comparator;
import java.util.Iterator;
import java.util.function.BiConsumer;
import java.util.stream.Stream;

public class Task03Main {

    public static void main(String[] args) {

        findMinMax(
                Stream.of(2, 9, 5, 4, 8, 1, 3),
                Integer::compareTo,
                (min, max) ->
                        System.out.println("min: " + min + " / max: " + max)
        );

    }

    public static <T> void findMinMax(
            Stream<? extends T> stream,
            Comparator<? super T> order,
            BiConsumer<? super T, ? super T> minMaxConsumer) {

        Iterator<? extends T> iterator = stream.iterator();

        if(!iterator.hasNext()){
            minMaxConsumer.accept(null, null);
        }
        else{
            T min = iterator.next();
            T max = min;
            while(iterator.hasNext()){
                T currentElem = iterator.next();
                if(order.compare(currentElem, min) < 0){
                    min = currentElem;
                }
                else if (order.compare(currentElem, max) > 0) {
                    max = currentElem;
                }
            }
            minMaxConsumer.accept(min, max);
        }
    }
}