What happens when calling a method with the @Transactional annotation inside a method that is not annotated with it in Spring?

If a method annotated with @Transactional is called from another method within the same class that is not marked with @Transactional, then a transaction will not be created. This is because Spring creates proxies to manage transactions, and calls to methods within the same class do not go through the proxy, so the annotation does not take effect.

For the transaction to work, the call to the method with @Transactional must occur from outside through the proxy, for example, from another bean. Otherwise, the code inside the method with @Transactional will execute without a transactional context.

Example:

@Service
public class MyService {

    public void outerMethod() {
        // Calling the internal method will not create a transaction
        innerTransactionalMethod();
    }

    @Transactional
    public void innerTransactionalMethod() {
        // Here, the transaction will not be active if called from outerMethod
    }
}