1. A SMALL RIDE WITH
CAMEL
Sunitha Raghurajan

2. WHAT IS APACHE CAMEL
Apache Camel is a powerful Open Source
Integration Framework based on known
Enterprise Integration Patterns
http://camel.apache.org

3. INTEGRATION PATTERNS
 A design pattern is a general reusable solution
to a commonly occurring problem within a given
context in software design
 Patterns don’t desribe a problem, and don’t
describe how to solve it-they tell you what to do
to solve it (Ref:Enterprise Integration Pattern)

4. WHY THE NAME CAMEL
Concise
Application
Messaging
Exchange
Language
 http://camel.apache.org/why-the-name-camel.html

5. WHO ARE CAMEL’S PARENTS

6. WHAT IS APACHE SERVICE MIX
 Lightweight Open Source ESB and SOA
Container
 Built on JBI Specification
 Supports OSGi
 Can run as a standalone ESB provider or as a
service within another ESB

7. ESB
 Platform
 Architecture Component
 Product

8. ESB
 Simplifies Integration and flexible reuse of
business components using Service Oriented
Architecture
 Glue that holds the compound application
together

9. WHAT IS ESB
http://i.msdn.microsoft.com/Cc487894.bddfbe7f-6ee2-4072-91f1-402c87ee92ad(en-us,MSDN.10).png

10. ESB ARCHITECTURE
 ESB Delivers messages from one point to another
 Bus architecture uses a central messaging backbone (bus)
for message propagation.
 Applications would publish messages to bus using
adapters.
 These messages would flow to subscribing applications
using message bus.
 Subscribing applications will have adapters
which would take message from bus and transform the
message into a format required for
the application.

11. BUS ARCHITECTURE
App A App B App C
Adapter Adapter B Adapter C
Messaging Backbone
Adapter Z Adapter G Adapter K
App Z App G App K

12. ESB ARCHITECTURE

13. WHAT IS SOA
 Service-Oriented Architecture (SOA) is an
architectural style.
 Applications built using an SOA style deliver
functionality as services that can be used or
reused on a network.
 Each service would achieve a predefined
business objective and perform discrete units of
work.
 The services are independent and do not depend
on the context or state of the other services. They
work within distributed systems architecture

14. WHAT IS A SERVICE
 A service is a reusable component that can be
used as a building block to form larger, more
complex business-application functionality.
 A service may be as simple as “get me some
person data,” or as complex as “process a
disbursement.”

15. WHY MESSAGING
 Asynchronous operation
− Send and Forget Approach
− Sender doesn’t have to wait for the receiver to
receive and process the message
Variable Timing
Disconnected Operation
Loose Coupling
− Systems connected via messaging need not be
aware of each other, or use the same technologies
− Key messages can easily be routed to many systems
Message broker is buffer in case of downtime

16. WHY MESSAGING
Remote Communication
Platform/Language Integration
communicate different systems running
different platforms, using different languages

17. WHY MESSAGING
 Parallelize Work
− Messages in a single stream can be handled
in parallel by many client threads or systems
 Throttle Work
− A large amount of work can be split across a
small number of threads or systems to
throttle effort

18. MESSAGING CONCEPTS
 Each message is sent to a particular named
“destination” (a topic or queue)
 Each message to a queue is processed by
exactly one consumer
Typically, one of many connected consumers
 Each message to a topic is processed by all the
consumers connected to that topic
− May even be saved for consumers that happen
to be disconnected at the moment

19. MESSAGE BROKER
Decouple the destination message from the Sender
And maintain central control over the flow
Of messages
Message
Broker

20. MESSAGING CONCEPTS
Message
Producer Message Broker
Topic Queue
Message Message Message
Consumer Consumer Consumer

21. ACTIVE MQ
 Apache ActiveMQ is an open source (Apache
2.0 licensed) message broker which fully
implements the Java Message Service 1.1 (JMS)
 JMS The Java API for messaging

22. CHARACTERISTICS OF ESB
Message Message
Service Mapping
Enhancement Transformation
Protocol
Routing Transmission
Transaction
Security Service Message Management
Orchestration Processing

23. OSGI
 The Open Services Gateway Initiative (OSGi)
Dynamic Module System for Java
Architecture for modular application
development.

24. JBI
 JBI is a java based standard to build integrations
systems by using plug-in components which
interoperates through mediated normalized
message exchanges.
 The message exchange model is based on the web
services description language (WSDL).

25. BACK TO CAMEL RIDE
 50 Enterprise Integration Patterns
http://camel.apache.org/eip

26. APACHE CAMEL (INSIDE THE BOX)
80 COMPONENTS
activemq cxf flatpack jasypt
activemq-
cxfrs freemarker javaspace
journal
amqp Dataset ftp/ftps/sftp jbi
atom Db4o gae jcr
bean direct hdfs jdbc
bean validation ejb hibernate jetty
browse esper hl7 jms
cache event http jmx
cometd exec ibatis jpa
crypto file irc jt/400

27. CAMEL (WHAT IS INSIDE )
18 DATA FORMATS
bindy protobuf
castor serialization
csv soap
crypto syslog
dozer tidy markup
flatpack xml beans
gzip xml security
hl7 xstream
jaxb zip
json

28. CAMEL(INSIDE THE BOX)
15 EXPRESSION LANGUAGES
BeanShell Python
EL Ruby
Groovy Simple
JavaScript SpEL
JSR 223 SQL
OGNL XPath
MVEL XQuery
PHP

29. Domain Specific Language
 Domain-specific language
● Routing can be defined in DSL
● Java DSL
 Fluent API that allows code completion by
your IDE
● Spring DSL
 Custom namespace with XML tags for routing
● Scala DSL
 Adding some Scala features on top of the
Java DSL

30. Questions

31. REFERENCES
 http://ggatz.com/images/Enterprise_20Integratio
n_20-_20SOA_20vs_20EAI_20vs_20ESB.pdf
 Camel in Action http://manning.com/ibsen