理解和解决Java多线程同步问题的实战案例

原创男娘i 2024-10-23 06:06 17阅读 0赞

Java多线程同步问题是编程中常见的挑战，主要是因为多个线程同时访问共享资源可能导致数据不一致。以下是一个实际的案例，我们将使用synchronized关键字来解决同步问题。

```java
// 假设我们有一个银行账户类
class BankAccount {
    private double balance;

// 方法加锁
    public synchronized void deposit(double amount) {
        // 检查金额是否有效
        if (amount < 0) {
            System.out.println("Deposit amount cannot be negative.");
            return;
        }

// 存款操作
        balance += amount;
        System.out.println("Deposit successful. New balance: " + balance);
    }

// 方法加锁
    public synchronized void withdraw(double amount) {
        // 检查金额是否有效
        if (amount < 0 || amount > balance) {
            System.out.println("Withdrawal amount is invalid or exceeds the current balance.");
            return;
        }

// 取款操作
        balance -= amount;
        System.out.println("Withdrawal successful. New balance: " + balance);
    }
}

// 测试多线程同步问题
public class BankAccountTest {
    public static void main(String[] args) {
        BankAccount account = new BankAccount();

// 创建两个线程，分别进行存款和取款操作
        Thread depositThread = new Thread(() -> {
            try {
                account.deposit(100);
            } catch (Exception e) {
                System.out.println("Error occurred during deposit: " + e.getMessage());
            }
        }));

Thread withdrawThread = new Thread(() -> {
            try {
                account.withdraw(50);
            } catch (Exception e) {
                System.out.println("Error occurred during withdrawal: " + e.getMessage());
            }
        }));

// 启动两个线程
        depositThread.start();
        withdrawThread.start();

// 等待所有任务完成
        depositThread.join();
        withdrawThread.join();

System.out.println("Final account balance: " + account.balance);
    }
}
```

这个案例展示了如何使用`synchronized`关键字来同步多个线程对共享资源的访问。在上述代码中，`deposit`和`withdraw`方法被加锁，确保同一时间只有一个线程可以执行这些方法。