What is the role of @Transactional in Spring?

In Spring, the @Transactional annotation specifies the transactional behavior of a method or class. This annotation can be applied to methods, interfaces, classes, or enums.

When the @Transactional annotation is applied to a method, it ensures that the method’s execution occurs within a single transaction. If the method is successful, the transaction is committed, but if it fails, the transaction is rolled back. This means that if an exception occurs during the method’s execution, all database operations are reverted to the state before the transaction began.

When the @Transactional annotation is applied to a class, it will be applied to all public methods within the class. This means that all public methods in the class will be executed in one transaction, with the same transaction attributes.

The @Transactional annotation can be configured with multiple properties to control the behavior of transactions, such as propagation behavior, isolation level, and read-only attribute. By configuring these properties, transaction behavior can be flexibly controlled to meet different business needs.

In conclusion, the purpose of the @Transactional annotation in Spring is to declare transaction boundaries, ensuring that methods or classes are executed within a transaction and providing flexible configuration to control transaction behavior.