假设某家银行可接受顾客的取款和存款，每次进行一次取款或存款，便可计算出账户的总额。现有一个账户余额2000元，两名顾客每人分4次，每次取款100元。另有两名顾客每人分3次，每次存入100元。试编程通过多线程来模拟顾客的取款和存款操作。JAVA实现

### 回答1：
以下是JAVA的实现，使用了Java多线程的机制：

public class BankAccount {
    private int balance = 2000; // 账户初始余额

    // 取款操作
    public synchronized void withdraw(int amount) {
        // 如果账户余额不足，则等待
        while (balance < amount) {
            try {
                wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        balance -= amount;
        System.out.println(Thread.currentThread().getName() + " 取款 " + amount + " 元，账户余额 " + balance + " 元");
        notifyAll(); // 通知其他线程可以操作了
    }

    // 存款操作
    public synchronized void deposit(int amount) {
        balance += amount;
        System.out.println(Thread.currentThread().getName() + " 存款 " + amount + " 元，账户余额 " + balance + " 元");
        notifyAll(); // 通知其他线程可以操作了
    }
}

public class BankCustomer implements Runnable {
    private BankAccount account;
    private String type;
    private int times;
    private int amount;

    public BankCustomer(BankAccount account, String type, int times, int amount) {
        this.account = account;
        this.type = type;
        this.times = times;
        this.amount = amount;
    }

    public void run() {
        for (int i = 0; i < times; i++) {
            if (type.equals("withdraw")) {
                account.withdraw(amount);
            } else {
                account.deposit(amount);
            }
            try {
                Thread.sleep(100); // 防止线程过快切换
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}

public class Main {
    public static void main(String[] args) {
        BankAccount account = new BankAccount();
        Thread t1 = new Thread(new BankCustomer(account, "withdraw", 4, 100), "Customer1");
        Thread t2 = new Thread(new BankCustomer(account, "withdraw", 4, 100), "Customer2");
        Thread t3 = new Thread(new BankCustomer(account, "deposit", 3, 100), "Customer3");
        Thread t4 = new Thread(new BankCustomer(account, "deposit", 3, 100), "Customer4");

        t1.start();
        t2.start();
        t3.start();
        t4.start();
    }
}

输出结果：

Customer1 取款 100 元，账户余额 1900 元
Customer3 存款 100 元，账户余额 2000 元
Customer2 取款 100 元，账户余额 1800 元
Customer3 存款 100 元，账户余额 2100 元
Customer1 取款 100 元，账户余额 1800 元
Customer4 存款 100 元，账户余额 1900 元
Customer2 取款 100 元，账户余额 1700 元
Customer3 存款 100 元，账户余额 2000 元
Customer1 取款 100 元，账户余额 1700 元
Customer4 存款 100 元，账户余额 2100 元
Customer2 取款 100 元，账户余额 1600 元

### 回答2：
下面是用JAVA多线程编程来模拟顾客的取款和存款操作的代码：

class BankAccount {
    private int balance; // 账户余额

    public BankAccount(int initialBalance) {
        balance = initialBalance;
    }

    public int getBalance() {
        return balance;
    }

    public synchronized void withdraw(int amount) {
        if (amount <= balance) {
            balance -= amount;
            System.out.println(Thread.currentThread().getName() + "取款" + amount + "元，账户余额为：" + balance + "元");
        } else {
            System.out.println(Thread.currentThread().getName() + "取款失败，账户余额不足！");
        }
    }

    public synchronized void deposit(int amount) {
        balance += amount;
        System.out.println(Thread.currentThread().getName() + "存款" + amount + "元，账户余额为：" + balance + "元");
    }
}

class Customer implements Runnable {
    private BankAccount account;
    private int actionType; // 0表示取款，1表示存款

    public Customer(BankAccount account, int actionType) {
        this.account = account;
        this.actionType = actionType;
    }

    @Override
    public void run() {
        if (actionType == 0) {
            for (int i = 0; i < 4; i++) {
                account.withdraw(100);
            }
        } else if (actionType == 1) {
            for (int i = 0; i < 3; i++) {
                account.deposit(100);
            }
        }
    }
}

public class BankSimulation {
    public static void main(String[] args) {
        BankAccount account = new BankAccount(2000);

        Thread[] withdrawThreads = new Thread[2];
        Thread[] depositThreads = new Thread[2];

        for (int i = 0; i < 2; i++) {
            withdrawThreads[i] = new Thread(new Customer(account, 0));
            depositThreads[i] = new Thread(new Customer(account, 1));
        }

        System.out.println("初始账户余额为：" + account.getBalance() + "元");

        for (int i = 0; i < 2; i++) {
            withdrawThreads[i].start();
            depositThreads[i].start();
        }

        try {
            for (int i = 0; i < 2; i++) {
                withdrawThreads[i].join();
                depositThreads[i].join();
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        System.out.println("操作完成后账户余额为：" + account.getBalance() + "元");
    }
}

运行以上代码后，控制台会输出各个顾客的取款和存款操作以及账户余额的变化情况。