using concat feature.

IntStream.java

package java0720_api;

import java.util.Arrays;
import java.util.stream.IntStream;


/**
 * Created by Junsuk on 2016-07-20.
 */
public class Java142_System {

    public static void main(String[] args) {
        int[] arr1 = {1, 5, 2, 4};
        int[] arr2 = {6, 3, 9, 7, 8};
        int[] arr3 = process(arr1, arr2);
        for (int data :
                arr3) {
            System.out.printf("%3d", data);

        }
    }

    public static int[] process(int[] arr1, int[] arr2) {
        int[] arr3;
        IntStream intStream = Arrays.stream(arr1);
        IntStream intStream2 = Arrays.stream(arr2);

        arr3 = IntStream.concat(intStream, intStream2).toArray();
        
        return arr3;

    }
}