Apache Camel introduction to integration framework

1. APACHE CAMEL:
SWISS KNIFE OF INTEGRATIONS
Justinas Šlekas

2. Agenda
• Integrations and Integration Patterns
• What is Apache Camel?
• Why Apache Camel?
• Camel basics
• Demo
• Questions

3. Why do we need integration?

4. Where does complexity come from?
Much of the complexity comes from two issues:
• dealing with the specifics of applications and transports
• coming up with good solutions to integration problems

5. Integrations patterns
- Visual pattern language for message-based enterprise
integration solutions
- Pattern language comprises of 65 patterns in 6 categories

6. Enterprise Integration Patterns

7. Why the name Camel?

8. Camel’s parents

9. What is Apache Camel?
• Java framework for integration and mediation
• Enterprise Integration Patterns
• Domain Specific Languages:
• Fluent Java
• Spring XML
• Blueprint XML
• Scala
• Runs in any container (or stand alone)
• Over > 150 out-of-box components
• Active community

10. Why Apache Camel?
• Why Integration Framework?
• Framework do the heavy lifting
• You can focus on business problem
• Not "reinventing the wheel"

11. Why Apache Camel?
• Integration can be messy - variety of protocols and data
formats
• Framework hides all complexity so you can focus on your
business logic

12. Apache Camel Deployment
Known ContainersDeployment Strategy
• No container dependency
• Lightweight
• Embeddable
Deployment Options
• Standalone
• WAR
• Spring
• J2EE
• JBI
• OSGi
• Cloud
• Apache ServiceMix
• Apache ActiveMQ
• Apache Tomcat
• Jetty
• JBoss
• IBM WebSphere
• Oracle WebLogic
• Oracle OC4j
• Glassfish
• Google App Engine
• ... others

13. Apache Camel Components
• Highly configurable
• Maximum interoperability
• Used to build “Adapters” to existing systems
• Don’t reinvent the wheel and end up with a box

14. (Some) Standard components
• AHC - Async HTTP client
• Atom
• AMPQ
• AWS-* - Amazon cloud services
• Bean - Bean binding
• DNS - DNS look-up
• Dropbox
• JPA
• File & FTP
• HBase
• HTTP
• LDAP
• MongoDB
• Mustache
• Netty
• POP3
• RabbitMQ
• Salesforce
• Servlet
• JMS & ActiveMQ
• SQL
• SSH
• Validation - XML validation
• Websocket
• XMPP
• Activiti BPMN
• Smooks

15. Why Camel? That’s why…

16. Apache Camel Concept
Camel is Message-oriented → Concept of
Message
Communication in Camel takes places via
Message
Message is included in Exchange

17. Apache Camel: Exchange
• Exchange = Wrapper
object
• encapsulates
Messages (IN and
OUT) and Metadata

18. Apache Camel: Endpoint
Endpoint defines the communication port of an application
from(“file://C:/data/in”)
to(“sftp://localhost:22/data/out”)

19. Apache Camel: Route
Route defines strategies for message manipulation

20. Camel Architecture

21. Working with Camel Messages
Camel Processor:
• Java interface used to implement message consumers or
Message Translator EIP
• you can create a Component from a Processor

22. Camel Processor

23. Apache Camel Bean
• Bean as Message Translator

24. Apache Camel Bean (2)
• Bean as Message Translator

25. Little Example
• File Copier Example

26. File Copier Example
Java DSL

27. File copier example
XML DSL route:
<route>
<from uri=“file://data/inbox”>
<to uri=“file://data/outbox”>
</route>
Java DSL route:
from(“file://data/inbox”).to(“file://data/outbox”)

28. What else is there?
• Error handling
• EIP annotations
• Test Kit
• Transactions
• Concurrency
• Interceptors
• Security
• Data Transformation
• Load Balancing
• ...

29. EIPAnnotations

30. Consumer Endpoint in Camel Bean

31. Producer Endpoint in Camel Bean

32. Transactions
Make client session with messaging system
transactional
• uses Spring transactions
• Transactional endpoints: JMS, ActiveMQ, AMPQ,
JPA

33. Error Handling
Two distinct types:
• transactional
• non-transactional
Can configure policies like:
• message redelivery
• dead-letter queue

34. Error Handling: Try - Catch

35. Load Balancer EIP
• delegate processing based on load balancing policies
• out-of-the-box-policies:
• Round robin
• Random
• Sticky
• Topic
• Failover
• Weighted Round-robin
• Weighted random ○ Custom

36. Load Balancer example

37. Camel as a Client
• Java Client Application (no routes)
• Example
• Upload a file to a FTP server

38. Testing
• Camel provides some very powerful Unit Testing
capabilities. Its MockEndpoint class supports complex
expressions to validate your routes.

39. Testing
Test Kit
• camel-test camel-test-spring
• camel-test-blueprint

40. Hawt.io - ultimate admin console
• lightweight html5 modular web-console
• open-source (JBoss Cummunity project)
• discovers what the JVM is running (JMX, other) and
exposes a web UI
• lots of plugins:
○ ActiveMQ
○ Camel
○ OSGi
○ Karaf
○ JMX
○ …..

41. Management with Hawt.io
• View/edit Camel Routes
• ActiveMQ - browse/send
• Monitor system resources
• Inspect JMX

42. When NOT to use Apache Camel?
• Integrating just one or two technologies (Could be simpler
to use other libraries)
• Very large integration projects (use ESB’s: Apache
ServiceMix, Mule ESB)

43. Summary
• Apache Camel: The Swiss Army Knife of Integration
• Lightweight
• Multiple container support
• Developer friendly
• Feature (a lot of components)
• Scalability
• Easy adoption in enterprises
• Development
• Testing
• Operations friendly
• License

44. DEMO
• Live demonstration

45. Speaker: Justinas Slekas
contacts: justas.slekas@gmail.com
Questions?