Hi ! Today is you last day. You will create a simple process: bufferize messages, and execute all of them in one time with MathOperations. You will use EIP chains for this.

This tutorial is based on EIP Buffer complex use case.

Definition of our integration process

You will use Enterprise Integration Patterns (EIP, see below for explanations) to create this process :

• Several messages are sent to an EIPAggregator pattern, which bufferize all incoming messages.
• Trigger message is sent to EipAggregator.
• EipAggregator sends an aggregated message to EipSPlitter.
• EipSplitter splits the aggregated message back into multiple messages.
• EipSPlitter sends the multiple messages to the operation AddIntegers on the service MathOperations.
• MathOperations.AddIntegers processes the messages and send you the responses.

Full Size

What is EIP ?
A set of design patterns for enterprise application integration.

What is Agregator pattern ?
[TODO]

What is Splitter Pattern ?
[TODO]

Configure the Splitter

1. Create a new EIP Technical service with the following configuration:

   Parameter name	Value
   JBI propertie
   Interface namespace	http://test.petalslink.com
   InterfaceName	EipSplitterInterface
   Service Namespace	http://test.petalslink.com
   Service Name	EipSplitter
   End-point Name	EipSplitterEndpoint
   Project Name and Location
   Project Name	su-EIP-EipSplitter-provide
   Specific Component properties
   Eip	Splitter
   Service Parameters
   Service Parameters	Select "su-jsr181-MathOperations-provide"	Auto-configuration
   XPath Condition
   XPath Condition	//*[local-name()="AddIntegers"]
   Additional Parameters
   Operation Namespace	http://test.petalslink.com
   Operation	AddIntegers
   Mep	InOut
   CDK properties
   Validate WSDL	false	There is no wsdl

Configure the Aggregator

1. Create a new EIP Technical service with the following configuration:

boolean(/*[local-name()="AddIntegers"\]/*[local-name()="equals"])

Create and deploy an EIP Service Assembly

There is a tight-coupling between both EIP. Assembling them in one single SA can be a good idea (especially with EIP, which can chain lots of patterns, each requiring a different SU).

1. Create a new Service Assembly.

   Service Assembly
   Name	sa-Eip-AggregatorSplitter

2. Add the two EIP Service-Units you created, and confirm.
3. Fast-export the Service Assembly for Petals.
4. Deploy in Petals ESB.

Understand XPath expressions

What is XPath ?

Run this tutorial (takes ~30 min) for Xpath : http://www.w3schools.com/XPath/default.asp
Now try to understand the XPath expressions we used. If you use EIP later, it is essential to understand and be able to write XPath.

EIP Agregator conditions

1. Elements which satisfy "aggregator-correlation" are aggregated

   <eip:aggregator-correlation>boolean(/*[local-name()="AddIntegers"])</eip:aggregator-correlation>

   Elements inside <AddIntegers> will be aggregated.

1. When "test" is true, aggregated message is sent.

   <eip:test>boolean(/*[local-name()="AddIntegers"]/*[local-name()="equals"])</eip:test>

   When <AddIntegers> contains the <equals> element, the aggregated message is sent to the next service, and buffer cleared.

EIP Splitter conditions

1. Elements which satisfy "test" are extracted and sent to the next service.

   <eip:test>//*[local-name()="AddIntegers"]</eip:test>

   <AddIntegers> elements are split and sent one by one.

Test the EIP chain

1. Deploy the SA containing the SU su-jsr181-MathOperations-provide.
2. Deploy the SA sa-Eip-AggregatorSplitter.
3. Send messages from webconsole, with InOut MEP (message exchange pattern).
4. Send the trigger message.

<AddIntegers xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" >
<integer1>1</integer1>
<integer2>2</integer2>
</AddIntegers>

<result xmlns="http://petals.ow2.org/petals-se-eip/aggregator">Aggregator: the content is buffered by the pattern</result>

<AddIntegers xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" >
<integer1>3</integer1>
<integer2>4</integer2>
</AddIntegers>

<AddIntegers xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" >
<integer1>5</integer1>
<integer2>6</integer2>
</AddIntegers>

<AddIntegers xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" >
<equals/>
</AddIntegers>

<result xmlns="http://petals.ow2.org/petals-se-eip/splitter">
<dlwmin:AddIntegersResponse xmlns:dlwmin="http://test.petalslink.com" xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
<returnMessage xmlns="">3</returnMessage>
</dlwmin:AddIntegersResponse>
<dlwmin:AddIntegersResponse xmlns:dlwmin="http://test.petalslink.com" xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
<returnMessage xmlns="">7</returnMessage>
</dlwmin:AddIntegersResponse>
<dlwmin:AddIntegersResponse xmlns:dlwmin="http://test.petalslink.com" xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
<returnMessage xmlns="">11</returnMessage>
</dlwmin:AddIntegersResponse>
</result>

More about orchestration

Look at other EIP patterns. Simple theory exercise: how would you do in this case....?

[TODO]

Other orchestration ways: BPEL, SCA, JSR181 or POJO. More info in this Orchestration Whitepaper.

EIP : Good performances. But complicated and a bit "dirty old way" (for example, do not use WSDL).
BPEL: Based on XML and WSDL. Standard. Quite complicated to learn. Poorer performances.
SCA: The simplest. Java code based on WSDL.
POJO or JSR181: Needs advanced Java programmation.
Custom JBI Component: Needs lot of skills. Best performances. Hard to maintain.