How can transaction management be implemented in Spring based on Aop?

In Spring, transaction management can be achieved by using AOP. The specific steps are as follows:

1. Configure a transaction manager: In the Spring configuration file, a transaction manager needs to be configured (such as DataSourceTransactionManager), which is responsible for managing the opening, committing, and rolling back of database transactions.
2. Configure transactional advice: Use the tag in Spring to configure a transactional advice (such as ), which will intercept methods annotated with @Transactional and manage transactions before and after method execution.
3. Annotation Transaction Methods: Add the @Transactional annotation to methods that require transaction management, allowing Spring to automatically begin, commit, or rollback transactions based on the annotation’s configuration.

The sample code is as follows:

@Service
public class UserService {
    @Autowired
    private UserDao userDao;
    
    @Transactional
    public void createUser(User user) {
        userDao.createUser(user);
    }
    
    @Transactional
    public User getUser(int userId) {
        return userDao.getUser(userId);
    }
}

In the above code, both the createUser() and getUser() methods are marked with the @Transactional annotation. This means that these two methods will be intercepted by the transaction manager when executed, and the transaction will be initiated, committed, or rolled back based on the annotation’s configuration.