How to use BTM as the transaction manager with Spring 2.x

These instructions have been verified against BTM 1.1.

Contents

Step 1: Copy the BTM jars

Include the following jars from the BTM distribution into your classpath:

Step 2: Configure connection pools beans

The first things you will need to configure are the connection pools.

Here is a sample bean configuration using Embedded Derby:

<bean id="derbyDataSource" class="bitronix.tm.resource.jdbc.PoolingDataSource" init-method="init" destroy-method="close">
	<property name="className" value="org.apache.derby.jdbc.EmbeddedXADataSource" />
	<property name="uniqueName" value="derby1" />
	<property name="minPoolSize" value="0" />
	<property name="maxPoolSize" value="5" />
	<property name="driverProperties">
		<props>
			<prop key="databaseName">users1</prop>
		</props>
	</property>
</bean>

Since the pools are created via the BTM API (ie: not with ResourceLoader) it is up to the API user to manage the lifecycle of the pools, mainly calling init() before usage and close() at shutdown.
This is why the two init-method and destroy-method attributes are set: to have Spring take care of that lifecycle.

Step 3: Configure BTM beans

The second thing you need to do is configure beans for BTM.

<!--  Bitronix Transaction Manager embedded configuration -->
<bean id="btmConfig" factory-method="getConfiguration" class="bitronix.tm.TransactionManagerServices">
	<property name="serverId" value="spring-btm" />
</bean>

<!-- create BTM transaction manager -->
<bean id="BitronixTransactionManager" factory-method="getTransactionManager"
	class="bitronix.tm.TransactionManagerServices" depends-on="btmConfig,derbyDataSource" destroy-method="shutdown" />

The TransactionManagerServices.getTransactionManager() call will initialize BTM. Before this, all connection pools should have been created and the configuration properties should have been set.
This is why the depends-on attribute is set: the BitronixTransactionManager bean must not be created prior its configuration bean and the required connection pools.
If this is problematic for you, please let us know by voting for BTM-4.

Step 4: Configure Spring PlatformTransactionManager

Next, you need to create a Spring PlatformTransactionManager. There are many of them but the one we are interested in is the JtaTransactionManager. This is required as Spring internally uses PlatformTransactionManager for all transactional work.

<!-- Spring JtaTransactionManager -->
<bean id="JtaTransactionManager" class="org.springframework.transaction.jta.JtaTransactionManager">
	<property name="transactionManager" ref="BitronixTransactionManager" />
	<property name="userTransaction" ref="BitronixTransactionManager" />
</bean>

This is really all you need to get JTA support with BTM inside Spring. You could directly make use of the JtaTransactionManager bean in your code but there are more elegant solutions: using Sping's AOP support to get declarative transaction management.

Step 5: Configure declarative transaction management

This can easily be achieved thanks to Spring's TransactionProxyFactoryBean.

The idea behind it is to wrap your bean with a Spring-generated proxy that will intercept calls and perform transaction management according to a configuration.

Here is short example:

<bean id="MyObjectFacade" class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean">
	<property name="transactionManager" ref="JtaTransactionManager" />
	<property name="transactionAttributes">
		<props>
			<prop key="*">PROPAGATION_REQUIRED, -Exception</prop>
		</props>
	</property>
	<property name="target" ref="MyObject" />
</bean>

This expects a MyObject bean to also be configured. You should then make use of the MyObjectFacade bean that will start a new transaction on any method call if no transaction is already running (the <prop key="*">PROPAGATION_REQUIRED piece), commit the transaction when the method returns or rollback the transaction if any exception is thrown (the , -Exception</prop> piece).

If you need more details on what can be done and how things are working refer to the TransactionProxyFactoryBean class javadoc.