利用java线程实现两人银行存取钱

在Java中，我们可以利用线程来模拟两个人同时在银行账户上存取钱的过程，这通常涉及到并发控制和同步机制，例如`synchronized`关键字或`ReentrantLock`。下面是一个简化的示例：

import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

class BankAccount {
    private double balance;
    private final Lock lock = new ReentrantLock();
    private Condition depositCondition = lock.newCondition();
    private Condition withdrawCondition = lock.newCondition();

    public void deposit(double amount) {
        lock.lock();
        try {
            if (amount > 0) {
                balance += amount;
                System.out.println("Thread " + Thread.currentThread().getName() + " deposited: " + amount);
                depositCondition.signalAll(); // 其他尝试存款的线程可以继续
            }
        } finally {
            lock.unlock();
        }
    }

    public synchronized void withdraw(double amount) {
        while (balance < amount) {
            try {
                withdrawCondition.await(); // 等待直到有足够的余额
            } catch (InterruptedException e) {
                Thread.currentThread().interrupt();
            }
        }
        if (amount <= balance) {
            balance -= amount;
            System.out.println("Thread " + Thread.currentThread().getName() + " withdrew: " + amount);
        } else {
            System.out.println("Insufficient balance.");
        }
    }
}

public class BankTransaction {
    public static void main(String[] args) throws InterruptedException {
        BankAccount account = new BankAccount();
        Thread t1 = new Thread(() -> account.deposit(500));
        Thread t2 = new Thread(() -> account.withdraw(200));

        t1.start();
        t2.start();

        t1.join();
        t2.join();
    }
}

在这个例子中，我们创建了一个`BankAccount`类，它有共享的`balance`变量和两个条件变量`depositCondition`和`withdrawCondition`，用于线程间的协作。当存款线程完成操作后会唤醒等待的取款线程，而取款线程只有在账户余额足够的情况下才会允许执行。