java - 单击“管理”按钮时，显示自动售货机 list

我一直在试图弄清楚如何获得“管理员”按钮以显示自动售货机中产品的当前库存以及单击时的现金余额，但是我似乎无法弄清楚如何。我最初尝试使用JOptionPane.showMessageDialog，但是尝试使用的所有方法均无效。

错误：


  找不到符号符号：方法getInv（Dispenser）位置：类VendingMachine.ButtonHandler ----（Alt-Enter显示提示）


主班

package vendingmachine;

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class VendingMachine extends JFrame {
//Constants
private static final int WIDTH = 500;
private static final int HEIGHT = 850;

//Object Variables
private JLabel headingL, selectionL;
private JButton candyB, chipsB, gumB, cookiesB, exitB, adminB;
private ButtonHandler bHandler;

//Instance Variables
private Register register = new Register();
private static Dispenser candy = new Dispenser();
private static Dispenser chips = new Dispenser(5,2);
private static Dispenser gum = new Dispenser(20,1);
private static Dispenser cookies = new Dispenser(5,3);

//Constructor
public VendingMachine() {

    setTitle("Brennan's Vending Machine");
    setSize(WIDTH,HEIGHT);
    setVisible(true);
    setDefaultCloseOperation(EXIT_ON_CLOSE);

    //Layout
    Container pane = getContentPane();
    pane.setLayout(new GridLayout(8,1)); //GRID LAYOUT (Button Spaces)

    //Create Lebels
    headingL = new JLabel("WELCOME TO BRENNAN'S VENDING MACHINE", SwingConstants.CENTER);
    selectionL = new JLabel("Click a button for your selection", SwingConstants.CENTER);

    //Create Buttons
    bHandler = new ButtonHandler();

    candyB = new JButton("candy");
    candyB.addActionListener(bHandler);
    chipsB = new JButton("chips");
    chipsB.addActionListener(bHandler);
    gumB = new JButton("gum");
    gumB.addActionListener(bHandler);
    cookiesB = new JButton("cookies");
    cookiesB.addActionListener(bHandler);
    adminB = new JButton("Admin");
    adminB.addActionListener(bHandler);
    exitB = new JButton("EXIT");
    exitB.addActionListener(bHandler);

    //Add objects
    pane.add(headingL);
    pane.add(selectionL);
    pane.add(candyB);
    pane.add(chipsB);
    pane.add(gumB);
    pane.add(cookiesB);
    pane.add(adminB);
    pane.add(exitB);

} //end Constructor

//Listener Event for Buttons
    private class ButtonHandler implements ActionListener {

        public void actionPerformed(ActionEvent e) {
            if(e.getActionCommand().equals("EXIT"))
            {
                System.exit(0);
            }
            else if(e.getActionCommand().equals("candy")) {
                sellProduct(candy, "Candy");
            }
            else if(e.getActionCommand().equals("chips")) {
                sellProduct(chips, "Chips");
            }
            else if(e.getActionCommand().equals("gum")) {
                sellProduct(gum, "Gum");
            }
            else if(e.getActionCommand().equals("cookies")) {
                sellProduct(cookies, "Cookies");
            }
            else if(e.getActionCommand().equals("Admin")) {
                JOptionPane.showMessageDialog(null, "Cookie Inventory: " + getInv(cookies));
            }
        }//end actionPerformed

    }//end ButtonHandler

    //Admin Output

    private void sellProduct(Dispenser product, String productName) {
        int itemPrice;

        if(product.getInv() > 0) {
            product.invOut();
            itemPrice = product.getProductCost();
            register.cashIn(itemPrice);
            JOptionPane.showMessageDialog(null, "Get Your " + productName, ". Item Dispensed", JOptionPane.PLAIN_MESSAGE);
        }
        else {
            JOptionPane.showMessageDialog(null,"This item is out of stock.");
        }
    }

public static void main(String[] args) {
    VendingMachine vending = new VendingMachine();
    System.out.println(candy.getInv());
}//end main

}//end class

库存处理程序类

package vendingmachine;

public class Dispenser {

//Instance Vars
private int productInv = 10;
private int productCost;

//Constructors
public Dispenser() {
    productInv = 10;
    productCost = 1;
}//end Inv()

public Dispenser(int productInv, int productCost) {
    this.productInv = productInv;
    this.productCost = productCost;
}//end Overloaded

//get Method
public int getInv() {
    return productInv;
}//end getInv()

public int getProductCost() {
    return productCost;
}

//Increment Inventory
public void invOut() {
    productInv -= 1;
}
}//end class

现金处理员类别

package vendingmachine;

public class Register {
//Instance Vars
private int cashBalance = 500;

//Constructor
public Register() {
    cashBalance = 500;
}//end Register()

public Register(int cashBalance) {
    this.cashBalance = cashBalance;
}//end overloaded

//get method
public int getBalance() {
    return cashBalance;
}

//Increment balance for sale
public void cashIn(int cashDepo) {
    cashBalance =+ cashDepo;
}
}//end class

最佳答案

好吧，错误本身很明显。

它找不到以getInv作为参数的名为Dispenser的方法。
您在这里调用getInv方法：JOptionPane.showMessageDialog(null, "Cookie Inventory: " + getInv(cookies));

在getInv类中定义了Dispenser（entory？）方法时，不带任何参数。因此，cookies.getInv();应该是正确的调用。