一个锁对synchronized的作用相同吗?

假设我有一个线程安全的银行帐户类,如下所示

class BankAccount {

    private long balance;

    public synchronized long getBalance() {
        return balance;
    }

    public synchronized void deposit(long amount) {
        balance += amount;
    }

    public synchronized void withdraw(long amount) {
        balance -= amount;
    }
}

使用锁有同样的效果吗?

class BankAccount {

    private long balance;

    private final Lock lock = new ReentrantLock();

    public long getBalance() {
        try {
            lock.lock();
            return balance;
        } finally {
            lock.unlock();
        }
    }

    public void deposit(long amount) {
        try {
            lock.lock();
            balance += amount;
        } finally {
            lock.unlock();
        }
    }

    public void withdraw(long amount) {
        try {
            lock.lock();
            balance -= amount;
        } finally {
            lock.unlock();
        }
    }
}