在Java中如何获取链表中的元素

    import java.util.*;
     
    public class Main {
       private LinkedList list = new LinkedList();
       public void push(Object v) {
      list.addFirst(v);
       }
       public Object top() {
      return list.getFirst();
       }
       public Object pop() {
      return list.removeFirst();
       }
       public static void main(String[] args) {
      Main stack = new Main();
      for (int i = 30; i < 40; i++)
         stack.push(new Integer(i));
      System.out.println(stack.top());
      System.out.println(stack.pop());
      System