I read about transaction management in spring using @Transactional annotation in our service methods or on service class and configuring our transaction with its propagation, isolation, timeout, readOnly attributes. Now my question is:
1) Do we still need to use synchronization (using synchronized keyword) or multi-threading if we are using @Transactional appropriately to achieve ACID properties?
2) What could be the different scenarios to still use java multi-threading in our Java EE web-application?
3) If multi-threading is required, what layer of our application should be using synchronized methods or blocks and what could be the reasons for that ?
I'm learning with the help of a dummy Online Banking project which I found in github. So it would be nice if the answers are connected to this scenario. So here are my classes (just to give you a idea):
//Here are some entity classes
@Entity public class User{...}
@Entity pulic class Account{...}
@Entity public class Card{...}
@Entity public class Operation{...}
// now some DAO examples
public class OperationDaoImpl implements OperationDao {
Page findNonCardByAccountIdAndYearMonth(Integer accountId, YearMonth yearMonth, Pageable pageable){...}
Page findTransferByAccountId(Integer accountId, Pageable pageable){...} DateTime getLastOperationDate(){...}
}
// now some service examples
@Service
@Transactional(readOnly = true)
@Validated
public class BankServiceImpl implements BankService {
public Map sumResolvedCardOperationsByAccountIdAndYearMonth(Integer accountId, YearMonth yearMonth) {...}
@Transactional(readOnly = false)
public void performTransfer(Integer debitedAccountId, Integer creditedAccountId, @Min(10) BigDecimal amount) throws UnsufficientBalanceException {...}
}
// and there are spring-mvc controllers.
Guys! sorry for making this question this long. Any kind of suggestion is welcome. Thanks.
