import java.util.List;
import java.util.ArrayList;
import java.util.Arrays;
 
public class ArrayMerge {
    public static void main(String[] args) {
        String[] a = { "A", "B", "C" };
        String[] b = { "D", "E", "F" };
        String[] c = merge(a, b);
        System.out.println(Arrays.toString(c));
    }
 
    public static String[] merge(String[]... arrays) {
        List<String> list = new ArrayList<String>();
 
        for (String[] array : arrays) {
            list.addAll(Arrays.asList(array));
        }
 
        String[] mergedArray = new String[list.size()]; 
        int start = 0; 
 
        for (String[] array : arrays) {
            System.arraycopy(array, 0, mergedArray, start, array.length); 
            start += array.length;     
        } 
        return mergedArray;
    }
}