棧的操作：

先封裝一個stack類

public class Stack {
    int top;
    int bottom;
    int arr[];

    public int getTop() {
        return top;
    }
    public void setTop(int top) {
        this.top = top;
    }
    public int getBottom() {
        return bottom;
    }
    public void setBottom
 
(int bottom) {
        this.bottom = bottom;
    }
    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + bottom;
        result = prime * result + top;
        return result;
    }
    @Override
    public boolean equals(Object obj) {
        if
 
 (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Stack other = (Stack) obj;
        if (bottom != other.bottom)
            return false;
        if (top != other.top)
            return
 
 false;
        return true;
    }
    public Stack(int top, int bottom) {
        super();
        this.top = top;
        this.bottom = bottom;
    }
    public Stack() {
        super();
    }
    @Override
    public String toString() {
        return "Stack [top=" + top + ", bottom=" + bottom + "]";
    }
}

實現基本操作

//初始化   構建一個空棧
    private static void initStack(Stack s) {
        s.arr = new int[n];//給棧申請空間
        s.top = s.bottom = 0;
        System.out.println("success");
    }

//入棧   在棧頂插入一個新的元素
    private static void posh(Stack s) {
        Scanner sc = new Scanner(System.in);
        if(s.top + 1 != n){//判斷是否     若棧未滿
            System.out.print("please enter the data:");
            s.arr[s.top] = sc.nextInt();
            s.top++;
            System.out.println("success");
        }else{//若棧滿   則入棧失敗
            System.out.println("the stack is full.");
        }
    }

//出棧  彈出棧頂元素
    private static int pop(Stack s) {
        int e = -1;

        if(s.top != s.bottom){//判斷棧是否為空  若不空
            s.top--;
            e = s.arr[s.top];
        }else{//若為空
            System.out.println("the stack is empty.");
        }

        return e;//返回元素的值
    }

//初始化   構建一個空棧
    private static void initStack(Stack s) {
        s.arr = new int[n];//給棧申請空間
        s.top = s.bottom = 0;
        System.out.println("success");
    }

main方法

private static int n = 5;//棧的最大空間
    public static void main(String[] args) {
        int op;

        Stack S = new Stack();
        Scanner sc = new Scanner(System.in);

        System.out.println("1.initialize\n2.push\n3.pop\n4.traverse");
        while(true){
            System.out.print("please ernter the operation code:");
            op = sc.nextInt();
            switch (op) {
            case 1:
                initStack(S);
                break;
            case 2:
                posh(S);
                break;
            case 3:
                int e = pop(S);
                System.out.println(e);
                break;
            case 4:
                int count = traverse(S);
                System.out.println(count);
                break;
            default:
                System.out.println("error.");
                break;
            }
        }
    }

示例：