PostConstruct and PreDestroy methods of Singletons with container-managed transactions are transactional. From the bean developer’s view there is no client of a PostConstruct or PreDestroy method.
A PostConstruct or PreDestroy method of a Singleton with container-managed transactions has transaction attribute REQUIRED, REQUIRES_NEW, or NOT_SUPPORTED (Required , RequiresNew, or NotSupported if the deployment descriptor is used to specify the transaction attribute).
Note that the container must start a new transaction if the REQUIRED (Required) transaction attribute is used. This guarantees, for example, that the transactional behavior of the PostConstruct method is the same regardless of whether it is initialized eagerly at container startup time or as a side effect of a first client invocation on the Singleton. The REQUIRED transaction attribute value is allowed so that specification of a transaction attribute for the Singleton PostConstruct/PreDestroy methods can be defaulted.