Harnessing Hibernate

Appendix D. Spring Transaction Support

Using the Spring Framework’s Transactional Annotation

You can put the Transactional annotation on either concrete classes or interfaces, and it can be placed on a class or a method. If a class is annotated with Transactional, the settings apply to every method defined in that class. If a method is annotated with Transactional, the transaction settings apply to a single method. If the Transactional annotation is present on both a class and a method, the settings from the method annotation take precedence over the class annotation.

From the Transactional annotation you can control the isolation level of a transaction, the timeout, the propagation setting, and an array of exceptions which should cause the transaction to roll back.

Note

If these terms are unfamiliar, the tables might help explain them.

For example, if we wanted to always create a new transaction with a serializable isolation level that would time out if not completed in one minute and would roll back on a NumberFormatException, we’d write code like Example D-1.

Example D-1. More control of transaction configuration

@Transactional(readOnly=false,
   propagation=Propagation.REQUIRES_NEW,
   isolation=Isolation.SERIALIZABLE,
   rollbackFor={NumberFormatException.class},
   timeout=60)
public abstract void run();

Warning

If you use the Transactional annotation, you need to be careful where you put the annotation. If you start using proxies in Spring, or if you start to delve into Spring’s compelling support ...