栈，先进后出

push

 public void push(E data){
   
       //链表实现不需要考虑溢出
       Node<E> node = new Node<>(data);
       node.next = head.next;
       head.next = node;
   }

pop

 public E pop(){
   
       if (isEmpty()){
   
           throw new RuntimeException("栈空");
       }
       Node<E> node = head.next;
       head.next = node.next;
       return node.data;
   }

isEmpty

 public boolean isEmpty(){
   
      return head.next == null;
  }

总览

package com.collection;

/**
 * @author WangYH
 * @version 2021.1.3
 * @date 2023/4/29 22:37
 */

public class LinkStack<E> {
   
   private final Node<E> head = new Node<>(null);

   public void push(E data){
   
       //链表实现不需要考虑溢出
       Node<E> node = new Node<>(data);
       node.next = head.next;
       head.next = node;
   }

   public E pop(){
   
       if (isEmpty()){
   
           throw new RuntimeException("栈空");
       }
       Node<E> node = head.next;
       head.next = node.next;
       return node.data;
   }

  public boolean isEmpty(){
   
      return head.next == null;
  }

   private static class Node<E> {
   
       private E data;
       private Node<E> next;

       public Node(E data) {
   
           this.data = data;
       }
   }
}

测试

package com.collection;

/**
 * @author WangYH
 * @version 2021.1.3
 * @date 2023/4/29 21:42
 */

public class Main {
   
    public static void main(String[] args) {
   
        LinkStack<String> stack = new LinkStack<>();
        stack.push("a");
        stack.push("b");
        stack.push("c");
        stack.push("d");
        while (!stack.isEmpty()) {
   
            System.out.println(stack.pop());
        }

    }
}