java array swap element

/**
 * @author lautturi.com
 * Java example: swap two elements of an array in java
 */

import java.util.*;
import java.time.*;

public class Lautturi {
	public static final <T> void swap(T[] a, int i, int j) {
		T t = a[i];
		a[i] = a[j];
		a[j] = t;
	}

	public static final <T> void swap(List<T> l, int i, int j) {
		Collections.<T>swap(l, i, j);
	}

	public static void main(String[] args) {
		String[] a = { "Hello", "world", "java", "lautturi" };
		swap(a, 1, 2);
		System.out.println("a:" + Arrays.toString(a));

		List<String> l = new ArrayList<String>(Arrays.asList(a));
		swap(l, 1, 3);
		System.out.println("l:" + l);
	}

}