Spring Integration and EIP Introduction

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Spring Integration

Connecting Enterprise Applications

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Topics in this session

• Introduction to Spring Integration• Spring Integration Compared• Enterprise Integration Patterns• Examples and demos• Summary and questions


The synchronous breakdown

• A customer orders a coffee– and waits

• The waiter walks to the barista and passes the order– and waits

• The barista walks to the coffee machine– and waits

• How about the next customer?


What is Messaging?

How can multiple agents work together?...

...without being in each others way.

Waiter helps customer and cook to collaborate.


Characteristics of Messaging

TransportThe waiter takes an order and moves it to the barista

AsynchronousDifferent actors do different things in parallel

Translationmenu item => number => recipe

RoutingOrders arrive back at the proper table


Why messaging (1/4)

Loose coupling


Why Messaging? (2/4)

Performance



Flexibility



Interception and filtering


Spring Integration


Hello world

<service-activator input-channel="inputChannel" default-output-channel="outputChannel" ref="helloService" method="sayHello"/>

<beans:bean id="helloService" class="...HelloService"/>

public class HelloService { public String sayHello(String name) { return "Hello " + name; }}


Hello world

inputChannel = context.getBean("inputChannel");

outputChannel = context.getBean("outputChannel");

inputChannel.send(new StringMessage("World"));System.out.println(

outputChannel.receive().getPayload());

$ java HelloWorldDemoHello World


Channels

<channel id="incoming"/>

<channel id="orderedNotifications"> <queue capacity="10"/></channel>


Channels


MessageEndpoints

SenderApplication

ReceiverApplication

Channel

MessageEndpoint

MessageEndpoints are the knots that tie applications to the integration solution.


Missing link

SenderApplication

ReceiverApplication

Channel

Invoked by Sender Who is responsible?


The Poller

<poller default="true"/>In Spring Integration:

you don't need to worry about it

A Message Bus enables separate applications to work together, but in a decoupled fashion such that applications can be easily added or removed without affecting the others.



• Introduction to Spring Integration• Comparing Spring Integration to others• Enterprise Integration Patterns• Examples and demos• Summary and questions


What’s different about Spring Integration?

• Can be used from within an existing application.

• Lightweight (like any Spring application):– run from JUnit test– run within webapp

• Focussed on messaging and integration• Not an ESB


Others in general

• Full blown ESB• It’s an application, not a framework

– You need to install it – You need to run it

• Typically a lot heavier• Focus on the deployment architecture

not the actual integration.


Mule

• Integrates with Spring• Lots of integration options:

– REST, SOAP– JMS

• Embeddable• Distribution

– 32Mb– 2Mb jar only (for embedding)


ServiceMix

• Based on JBI – (Mediated Message Exchange Model)

• Distribution:– 100mb

• http://servicemix.apache.org/how-to-evaluate-an-esb.html

http://servicemix.apache.org/how-to-evaluate-an-esb.html


Camel

• Most direct competition for Spring Integration

• Less consistent with Spring• Focus on routing• Fluent interface as an alternative to xml


Considerations

• Routing complexity– a bus can be useful for more complex

routing problems

• Comfort zone– what will the developers feel at home with

• Keep it clean– don’t scatter the routing rules

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Basic Integration

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With a bus


Message Router

• Takes messages from a channel and forwards them to different channels


Competing Consumers

• Multiple consumers take messages from the channel

• First come first serve


Competing Consumers


Selective Consumer

• Select only relevant messages• Reduces the need for dedicated

channels


Selective Consumer


Splitter


Detour


Demo Time


Summary

• Spring Integration– works from existing Spring applications– lightweight– decentralized (if you want)

• Enterprise Integration Patterns– describe ways of plumbing the enterprise

application landscape.


Questions and Plugs

• You can ask questions now while you ignore these shameless plugs

• Thanks to Babiche Israel (cartoons)– http://babicheisrael.blogspot.com/

• Come to Java meetup May 23– http://tinyurl.com/66hfnt or– Google for ‘java meetup q2 2008’

http://tinyurl.com/66hfnt

Spring Integration and EIP Introduction

Technology

Transcript of Spring Integration and EIP Introduction