How is transaction support implemented using the @Transactional annotation in Spring Framework?

The @Transactional annotation in the Spring Framework is implemented using aspect-oriented programming (AOP). When a method is marked with @Transactional, Spring creates a proxy object that wraps the method call.

When such a proxy method is invoked:

1. It starts a transaction (if one is not already started).
2. It executes the method itself.
3. If the method completes successfully, the transaction is committed.
4. If an exception occurs, the transaction is rolled back.

Thus, @Transactional manages the transaction lifecycle automatically, freeing the developer from manual transaction management.

This works thanks to the Spring Transaction Manager, which integrates with the chosen data source (e.g., JDBC, JPA).