Java Definir valor do Arraylist

import java.util.ArrayList;

public class SetExample {
  public static void main(String args[]) {
    ArrayList<Integer> arraylist = new ArrayList<Integer>();
    arraylist.add(1);
    System.out.println(arrayList.get(0));
    //1
	arrayList.set(0, 2)
    System.out.println(arrayList.get(0));
    //2
  }
}
Joyous Jay