What should be taken into consideration when using @Tra…

When using the @Transactional annotation, it is important to keep in mind the following points:

1. Behavior of transaction propagation: Specify the behavior of transaction propagation through the ‘propagation’ attribute of @Transactional, including options like REQUIRED, REQUIRES_NEW, and SUPPORTS. Make sure to select the appropriate propagation behavior to ensure the correct execution of transactions.
2. Transaction isolation levels can be specified using the isolation attribute of @Transactional, including options such as DEFAULT, READ_UNCOMMITTED, READ_COMMITTED, etc. It is important to understand the meanings and effects of different isolation levels and choose the most suitable one.
3. Rollback strategy: Specify which exceptions trigger transaction rollback using the rollbackFor attribute of @Transactional. By default, Spring only rolls back transactions when encountering RuntimeException or Error, other exceptions will not trigger a rollback. Set appropriate rollback strategy based on business needs.
4. Transaction timeout setting: Specify the transaction timeout in seconds using the timeout attribute of @Transactional. If the transaction exceeds the specified time and is still not completed, it will be rolled back. Set a suitable timeout time according to your business needs.
5. By default, Spring automatically commits the transaction after method execution. If you need to manually trigger the transaction commit, you can use the commit method of the TransactionSynchronizationManager class.
6. Exception handling: When using the @Transactional annotation, any exception thrown by a method will automatically be converted into an exception type within Spring’s unified exception system. Therefore, it is necessary to handle exceptions appropriately based on business needs to ensure that transactions are rolled back correctly.
7. Transaction propagation for external calls: When using the @Transactional annotation, if method A calls method B and method B also has the @Transactional annotation, whether B joins A’s transaction depends on the propagation behavior setting of method B. If the propagation behavior of method B is REQUIRED, then B will join A’s transaction; if it is REQUIRES_NEW, then B will create a new transaction.

In conclusion, when using the @Transactional annotation, it is important to consider aspects such as transaction propagation behavior, isolation level, rollback policies, and timeout settings, and to set and handle transactions accordingly based on business requirements.