Java Reference
In-Depth Information
<beans:property name="targetMethod" value="validateInventory"/>
</beans:bean>
<step id="creditVerificationStep">
<tasklet>
<chunk reader="orderReader" processor="creditVerificationProcessor"
writer="orderWriter" commit-interval="10"/>
</tasklet>
</step>
<step id="inventoryVerificationStep">
<tasklet>
<chunk reader="orderItemReader" processor="inventoryVerificationProcessor"
writer="orderWriter" commit-interval="10"/>
</tasklet>
</step>
<job id="parallelJob">
<step id="step1" parent="preloadDataStep" next="step2"/>
<step id="step2" parent="batchOrderProcessingStep" next="parallelProcessing"/>
<split id="parallelProcessing" task-executor="taskExecutor">
<flow>
<step id="step3" parent="creditVerificationStep"/>
</flow>
<flow>
<step id="step4" parent="inventoryVerificationStep"/>
</flow>
</split>
</job>
…
Listing 11-16 shows the configuration of the required ItemReaders and ItemWriters as you would
expect as well as
creditService
and
inventoryService
. You use
ItemProcessorAdapter
to turn your
services into ItemProcessors and finally wire up each of the steps. It's in the job itself that things get
interesting for this example.
Within
parallelJob
, you begin with step 1, which points to step 2 (via the
next
attribute). However,
step 2 doesn't point to a step in the
next
attribute. Instead, it points to the
split
tag. Within the
split
tag, you define two flows: one for the credit-card verification (using
creditVerificationStep
) and one
for inventory verification (using
inventoryVerificationStep
). These two flows are executed at the same
time. The
parallelProcessing
“step” is considered complete when both steps have completed.
That's it for the parallel processing aspect of the job. The final step, generation of the pick lists is
executed once the split pseudostep is complete. In the next section you will look at the required code for
the step and how that step is configured.
Building the Picklists
The final piece of the puzzle for this job is to write out picklists for the warehouse to pull the items. In
this case, you generate one picklist for each order that passed the credit-verification step
(
creditValidated
=
true
) and for which all the
OrderItem
s in the order passed the inventory check
(
inventoryValidated
=
true
). For this you have a
HibernateCursorItemReader
that reads only the
