用Java代码写一个自动贩卖机 能够添加饮料 打印欢迎词 列出饮料信息 付钱挑饮料 交付饮料并从贩卖机中弹出（对应空位空出） 显示购买后找的钱 显示贩卖机余额

以下是一个简单的Java代码实现：

import java.util.HashMap;
import java.util.Scanner;

public class VendingMachine {

// 饮料库存数量
private static HashMap<String, Integer> drinkInventory = new HashMap<>();
// 饮料售价
private static HashMap<String, Integer> drinkPrice = new HashMap<>();
// 贩卖机余额
private static int balance = 0;

public static void main(String[] args) {
// 初始化饮料信息
drinkInventory.put("可乐", 10);
drinkInventory.put("雪碧", 10);
drinkPrice.put("可乐", 3);
drinkPrice.put("雪碧", 2);

System.out.println("欢迎使用自动贩卖机！");
while (true) {
System.out.println("请输入您要选择的操作：");
System.out.println("1. 添加饮料");
System.out.println("2. 查看饮料信息");
System.out.println("3. 购买饮料");
System.out.println("4. 退出");

Scanner scanner = new Scanner(System.in);
int choice = scanner.nextInt();

switch (choice) {
case 1:
addDrink();
break;
case 2:
listDrinkInfo();
break;
case 3:
buyDrink();
break;
case 4:
System.out.println("欢迎下次再来！");
System.exit(0);
break;
default:
System.out.println("输入有误，请重新输入！");
break;
}
}
}

// 添加饮料
private static void addDrink() {
System.out.println("请输入要添加的饮料名称：");
Scanner scanner = new Scanner(System.in);
String drinkName = scanner.nextLine();

if (drinkInventory.containsKey(drinkName)) {
System.out.println("该饮料已存在，若需增加数量请选择购买饮料操作。");
return;
}

System.out.println("请输入饮料数量：");
int drinkCount = scanner.nextInt();
System.out.println("请输入饮料售价：");
int drinkPrice = scanner.nextInt();

drinkInventory.put(drinkName, drinkCount);
VendingMachine.drinkPrice.put(drinkName, drinkPrice);
System.out.println(drinkCount + " 瓶 " + drinkName + " 添加成功！");
}

// 查看饮料信息
private static void listDrinkInfo() {
System.out.println("当前贩卖机余额为：" + balance);
System.out.println("饮料名称\t饮料库存\t饮料单价");
for (String drinkName : drinkInventory.keySet()) {
System.out.println(drinkName + "\t\t" + drinkInventory.get(drinkName) + "\t\t" + drinkPrice.get(drinkName));
}
}

// 购买饮料
private static void buyDrink() {
System.out.println("请选择要购买的饮料：");
for (String drinkName : drinkInventory.keySet()) {
System.out.println(drinkName + " - 售价：" + drinkPrice.get(drinkName));
}

Scanner scanner = new Scanner(System.in);
String drinkName = scanner.nextLine();

if (!drinkInventory.containsKey(drinkName)) {
System.out.println("抱歉，该饮料不存在。");
return;
}

int drinkCount = drinkInventory.get(drinkName);
if (drinkCount == 0) {
System.out.println("抱歉，该饮料已卖完。");
return;
}

System.out.println("请输入支付金额：");
int money = scanner.nextInt();
if (money < drinkPrice.get(drinkName)) {
System.out.println("支付金额不足，购买失败。");
return;
}

int change = money - drinkPrice.get(drinkName);
System.out.println("购买成功，找零 " + change + " 元。");
balance += drinkPrice.get(drinkName);
drinkInventory.put(drinkName, drinkCount - 1);
System.out.println("请取走您的 " + drinkName + " 饮料。");
}
}