Concat Arrays

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

public class Main {
    public static void main(String[] args) {
        int[] array1 = {65, 87, 234, 0, 344, -112, 54543, 4234, 111, 1, 666};
        int[] array2 = {76, 2323, 9789, -25245, -5345, 88, 0, 111, 33, 434, 7657567, 232, -5435, 123, 678, -666};

        Arrays.sort(array1);
        Arrays.sort(array2);

        int[] newArray = concatArrays(array1, array2);
        for (int i : newArray)
            System.out.println(i);
    }

    private static int[] concatArrays(int[] a, int[] b) {
        ArrayList<Integer> list = new ArrayList<>();

        int i = 0;
        int j = 0;

        while (i < a.length && j < b.length) {
            if (a[i] <= b[j]) {
                list.add(a[i]);
                i++;
            }
            else {
                list.add(b[j]);
                j++;
            }
        }

        if (i == a.length)
            for (int k = j; k < b.length; k++)
                list.add(b[k]);

        if (j == b.length)
            for (int k = i; k < a.length; k++)
                list.add(a[k]);

        return list.stream().mapToInt(Integer::valueOf).toArray();
    }
}