Claimcheck Pattern with vFabric RabbitMQ and Gemfire

 For people in hurry refer the steps to run this sample.

In continuation to my earlier blog on Claimcheck Pattern in this blog I use AMQP backed message channel to simplify implement Claimcheck Pattern. There is also another good blog on Spring Integration – Payload Storage via Claim-check, which talks about Claimcheck Pattern

The Enterprise Integration Pattern flow is as below,

Claimcheck pattern with vFabric RabbitMQ and Gemfire

The use case in this blog is, there is a message that gets posted on to a Queue, the message checks into a vFabric Gemfire messageStore, and a GUID is extracted and posted on to a vFabric RabbitMQ Exchange. The subscribers listening to that Exchange and will get the GUID and checks out of the messageStore and calls a Service activator.

As per the Test First development, the JUnit test case looks as below,

@Test
public void testIntegration() {
String request = streamToString(getClass().getResourceAsStream(
"/data/payload.xml"));
Message<String> message = MessageBuilder.withPayload(request)
.build();
channel.send(message);
String outMessage = outChannel.receive(1000).getPayload().toString();
assertEquals(outMessage, request);
}

In the test code, since there is no transformation, we just compare the input data to the data coming out of the target channel.

The test configuration looks as below,

<int:channel id="p2p-pollable-channel" />
<int:publish-subscribe-channel id="pub-sub-channel" />
<int:channel id="checkout-channel3" >
<int:queue />
</int:channel>
<int:claim-check-out message-store="simpleMessageStore"
input-channel="pub-sub-channel" output-channel="checkout-channel3"
remove-message="false" />

In the main configuration the vFabric RabbitMQ configuration looks as below,

<!-- A reference to the org.springframework.amqp.rabbit.connection.ConnectionFactory -->
<rabbit:connection-factory id="connectionFactory" />
<!-- Creates a org.springframework.amqp.rabbit.core.RabbitAdmin to manage
exchanges, queues and bindings -->
<rabbit:admin connection-factory="connectionFactory" />
<int-amqp:channel id="p2p-pollable-channel" connection-factory="connectionFactory" />
<int-amqp:publish-subscribe-channel id="pub-sub-channel" connection-factory="connectionFactory" />

Finally the integration flow demonstrate the claim checkin and claim checkout as below,

<int:claim-check-in message-store="simpleMessageStore"
input-channel="p2p-pollable-channel" output-channel="pub-sub-channel" />

<int:claim-check-out message-store="simpleMessageStore"
input-channel="pub-sub-channel" output-channel="checkout-channel1"
remove-message="false" />

<int:claim-check-out message-store="simpleMessageStore"
input-channel="pub-sub-channel" output-channel="checkout-channel2"
remove-message="false" />

If you notice carefully, “p2p-pollable-channel” and “pub-sub-channel” are physical Queues and Exchanges in vFabric RabbitMQ as per the last blog on Amqp Backed Spring Integration Using vFabric Rabbitmq