交换ArrayList里的元素

import java.util.ArrayList;
import java.util.Collections;

public class SwapElements {

public static void main(String[] args) {
    // TODO Auto-generated method stub
    ArrayList arrayList = new ArrayList();
        arrayList.add("A");
        arrayList.add("B");
        arrayList.add("C");
        arrayList.add("D");
        arrayList.add("E");
       
        System.out.println("Before swaping, ArrayList contains : " + arrayList);
       
        Collections.swap(arrayList,0,4);
       
        System.out.println("After swaping, ArrayList contains : " + arrayList);
}

}

Console：
Before swaping, ArrayList contains : [A, B, C, D, E]
After swaping, ArrayList contains : [E, B, C, D, A]