Java 获得链表的元素

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.out.println(stack.pop());
      System.out.println(stack.pop());
   }
}