عرض عملي: اكتشاف خطأ الاستدعاء الذاتي (Self-invocation)

خطوة بخطوة

1. Run the money-transfer exercise: a failure after debit leaves money missing.
2. Check the code: transfer() calls this.debitAndCredit(), which has the annotation.
3. Prove it with the transaction log (logging.level.org.springframework.transaction=TRACE): no transaction begins.
4. Planned mistake: mark the private method @Transactional and show it still does nothing.
5. Fix it by moving the method to another bean (or annotating the public entry point); re-run the failure test.