Its quite common in Spring applications you want to deploy a JTA TransactionManager in your Spring.xml. To do this in Jencks add the following to your spring.xml

<bean id="transactionManager" class="org.jencks.factory.TransactionManagerFactoryBean"/>

This will by default instantiate the Geronimo TransactionManager which will be capable of full XA.

If you want to use full XA recovery, so that pending XA transactions are recovered on JVM restart, you must configure the TransactionManager factory bean with a transaction log such as Howl using the transactionLog_ property.

The above bean definition for the Jencks JTA Transaction Manager is good for version 2.0 of Jencks. For version 1.3 you must define the bean a bit differently in your Spring configuration XML:

<bean id="transactionManager" class="org.springframework.transaction.jta.JtaTransactionManager" autowire="constructor">
    <constructor-arg>
        <bean class="org.jencks.factory.TransactionManagerFactoryBean" />
    </constructor-arg>
</bean>