Transactions

The SeedStack/Spring bridge add-on allows to trigger transactions across framework boundaries.

You can:

• Manage Spring transactions from SeedStack code,
• Manage SeedStack transactions from Spring code.

SeedStack-managed transactions

You can specify a Spring-based transaction handler in your Seed transaction demarcation by adding the @SpringTransactionManager annotation next to the @Transactional one.

Consider the following Spring transaction manager:

<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
    <property name="entityManagerFactory" ref="someEmf" />
</bean>

You can trigger transactions on this Spring transaction manager from SeedStack as below:

public class SomeClass {
    @Inject
    @Named("customerDao")
    private CustomerDao customerDao;

    @Transactional
    @SpringTransactionManager
    public void someMethod() {
        // do something transactional with the customerDao Spring bean
    }
}

Spring-managed transactions

Seed has the ability to inject a Spring-configured JPA EntityManger in your SeedStack classes. In that case, Spring is be managing the JPA transactions. SeedStack code is executed within the Spring transaction. This feature can be very useful in batch jobs, when you need to let Spring batch manage transactions for performance reasons.

Spring configuration

As stated above Spring will be the one that will manage all JPA features (mapping, transaction …). As such, your Spring context files need contain a complete JPA configuration (datasource + entity manager factory + transaction manager).

SeedStack configuration

SeedStack JPA add-on should be removed if possible or at least left un-configured. Additionally, the SeedStack/Spring bridge must be configured as below:

spring:
  manageJpa: true