java - 为什么这个 Java 代码不起作用？!通用堆栈

Question

我是 Java 泛型的新手，我真的需要这段代码的帮助它没有编译我不知道为什么!
堆栈类是:

 public class GenericStack<Item>{
    public class Stack {

        private Node first=null;

        private class Node {
            Item item;
            Node next;
        }

        public boolean IsEmpty()
        {
            return first==null;
        }

        public void push (Item item)
        {
            Node oldfirst = first;
            first = new Node();
            first.item = item;
            first.next = oldfirst;
        }

        public Item pop ()
        {
            Item item=first.item;
            first=first.next;
            return item;
        }
    }
}

这是主要的

public class Main {

/**
 * @param args
 */
public static void main(String[] args) {
    // TODO Auto-generated method stub
    GenericStack<Integer> ob = new GenericStack<Integer>();
    ob.push(5);
    obpush(10);
    ob.push(15);
    while (!ob.IsEmpty())
    {
        int x=ob.pop();
        StdOut.print(x);
    }

  }
}

现在错误是:

  The method push(int) isn't defined for the type GenericStack<Integer>

我哪里错了？!谁能给我解释一下

提前致谢

Answer 1

您的GenericStack 类没有方法。摆脱嵌套的类结构，直接使用 Stack 的泛型类型参数:

public class Stack<Item> {

    private Node first=null;

    private class Node {
        Item item;
        Node next;
    }

    public boolean IsEmpty()
    {
        return first==null;
    }

    public void push (Item item)
    {
        Node oldfirst = first;
        first = new Node();
        first.item = item;
        first.next = oldfirst;
    }

    public Item pop ()
    {
        Item item=first.item;
        first=first.next;
        return item;
    }
}