java – How to convert an ArrayList<Long> list = new ArrayList&lt;&gt;() into a long[] array?

Question:

Please tell me the best solution (short). Let's say we are given a list ArrayList<Long> list = new ArrayList<>() , and we need to convert it to a long[] data array.

Answer:

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Objects;

public class Main {
    public static void main(String[] args) {
        ArrayList<Long> list = new ArrayList<>();
        list.add(1L);
        list.add(2L);
        list.add(3L);
        list.add(4L);
        long[] longsPrimitive = list.stream()
                .filter(Objects::nonNull)
                .mapToLong(Long::longValue)
                .toArray();
        System.out.println(Arrays.toString(longsPrimitive));
    }
}