This will submit
a single order in the back end, but the order can contain multiple order items. Now,
for each order item, we need to do a separate inventory check. To solve this problem,
we can route the order to an XPath splitter first. The splitter can split the order into
individual order items and each order item can be pushed to the queue as a separate
message. Now it is easy to plug-in a content-based router as we have discussed
already. Then each new message encapsulating one order item can be routed to their
respective inventory queues.
Enterprise Integration Patterns in ESB
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Sample Use Case
The sample use case will have the following components:
JMS client: This is a normal external JMS client, placing the XML composite
messages onto the JMS consumer component configured within the ESB.
JMS consumer: This is a servicemix-jms listening on queue "A". Any
incoming messages to this queue will be routed to the next component in the
flow chain which is the XPath splitter.
XPath splitter: The XPath splitter is a servicemix-eip component. On
receiving the in messages, the splitter will try to match the XPath configured
at the splitter-level with the message content.
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