Presentation held at DOAG 2023 in Nuremberg. Integration is the basis for the modernization of IT system landscapes! This talk is about the challenges of integrating applications and systems in organizations and how Apache Camel and Quarkus can be used as integration tools to efficiently overcome these challenges. We will give an overview of our idea of building an integration architecture and its components and show how integration solutions can be implemented quickly and efficiently based on it. We will discuss the advantages of Camel and Quarkus and present practical examples and best practices. We will also look at the concepts of microservices and event-driven architecture and show how these can be integrated into integration solutions.

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Integration architectures with Camel and Quarkus 1
Nuremberg, 2023-11-23
Sven Bernhardt
INTEGRATION ARCHITECTURES
WITH CAMEL AND QUARKUS

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THAT‘S ME
Integration architectures with Camel and Quarkus 2
Sven Bernhardt
Cloud-Native enthusiast, API & integration geek. Always curious how new
technologies and concepts can help to make things more valuable and efficient.
@sbernhardt
https://svenbernhardt.wordpress.com/
Chief Architect / Integration Evangelist
OPITZ CONSULTING Deutschland
GmbH

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Integration architectures with Camel and Quarkus 3
INTEGRATION – WHY
AND WHAT?
01
ENTERPRISE
INTEGRATION PATTERNS
02
QUARKUS & APACHE
CAMEL
04
APACHE CAMEL
03
CONCLUSION
05

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Integration architectures with Camel and Quarkus 4
INTEGRATION – WHY AND WHAT?
01

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This is what it looks like sometimes/often/always in application
landscapes...
https://www.youtube.com/watch?v=iXaw70X7wb4&t=2s
Integration architectures with Camel and Quarkus Seite 5

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INTEGRATION CHALLENGES ARE MULTIDIMENSIONAL
Integration architectures with Camel and Quarkus 6

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LEGACY INTEGRATION WITH MONOLITHIC ESB SOLUTIONS
¢ Monolithic architecture
¢ Often classic JEE deployments
¢ Integrations share single execution process
¢ Limited freedom of technology choice
¢ Core component:
¢ ESB Platform (Oracle Service Bus, Sonic ESB)
¢ Reverse Proxy for handling external traffic
¢ Focus on horizontal integration challenges
Integration architectures with Camel and Quarkus 7

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TALKING ABOUT INTEGRATION MEANS TALKING ABOUT VARIOUS
INTEGRATION SCENARIOS AND ASPECTS
Integration architectures with Camel and Quarkus 8
¢ Integration always needs to consider systems, data and processes
¢ Synchronous as well as asynchronous APIs
¢ REST, GraphQL, gRPC, SOAP, WebSockets, Server-Sent Events, Webhooks, etc.
¢ AsyncAPI, CloudEvents, etc.
¢ Data format transformations
¢ Protocol transformations
¢ Batch vs. Near-realtime vs. Streaming
Source: https://www.postman.com/state-of-api/api-technologies/#api-technologies

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MOVE TO THE CLOUD AND CLOUD-NATIVE PRINCIPLES FURTHERS
TREND TO DECENTRALIZATION
Integration architectures with Camel and Quarkus 9
Centralized
STATIC
ON-PREM
MONOLITH
VIRTUAL MACHINES
MANUAL CHANGE PROCESS
Decentralized
DYNAMIC
CLOUD / MULTI-CLOUD
MICROSERVICES / SERVERLESS
CONTAINERS, KUBERNETES
AUTOMATED CI/CD TOOL CHAIN
# Services & APIs
CONTROL AND VISIBILITY

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INTEGRATION? IT’S JUST ABOUT BOXES AND LINES!
Goals:
¢ Enabling systems to talk to each other
¢ Ensure that data is where it is needed when it is needed in the form in which it is needed
Gregor Hohpe
A small line. That‘s where the beef is!
Integration architectures with Camel and Quarkus 10

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INTEGRATION IS BASED ON PATTERNS INDEPENDENT OF TECH
Content-based Router
Message Filter
Splitter
Aggregator
Normalizer
Resequencer
https://www.enterpriseintegrationpatterns.com
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ENTERPRISE INTEGRATION
PATTERNS
02

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INTEGRATION IS BASED ON PATTERNS STABLE FOR DECADES
Content-based Router
Message Filter
Splitter
Aggregator
Normalizer
Resequencer
https://www.enterpriseintegrationpatterns.com
Integration architectures with Camel and Quarkus 13

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EIP BASIC CONSTRUCTS
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¢ Message
¢ Wrapper for data
¢ Consists of a header and a body
¢ Endpoint
¢ Endpoints enable systems to interact
¢ Using endpoints systems can exchange
information
¢ Channel
¢ Endpoints publish messages to channels
¢ Listening endpoints consume messages from
a channel
Message
Endpoint
Channel

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BASIC IDEA: PIPES AND FILTERS
Integration architectures with Camel and Quarkus 15
¢ Purpose: Divide a larger processing step into
¢ Smaller independent steps (Filters)
¢ Connected by channels (Pipes)
¢ Filters are connected by pipes
¢ General filter flow:
¢ Receive an incoming message from the
inbound pipe
¢ Process message
¢ Publish message to the outbound pipe
Pipes
Filters

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MESSAGE TRANSLATOR
Integration architectures with Camel and Quarkus 16
¢ Purpose: Enable systems that use different
data formats to communicate with each
other
¢ Semantic as well as syntactical
transformations are possible:
¢ System-specific objects to domain objects
¢ Protocol transformation: XML to JSON
Source:
https://www.enterpriseintegrationpatterns.com/patterns/messaging/MessageTranslator.html

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BASIC EIP: MESSAGE ROUTER
Integration architectures with Camel and Quarkus 17
¢ Purpose: Route a message to a recipient
based on the message content
¢ The message is received on an inbound
channel and republished to another channel
depending on a set of conditions
¢ Concrete implementation variants:
¢ Header-based router
¢ Content-based router
Source:
https://www.enterpriseintegrationpatterns.com/patterns/messaging/MessageRouter.html

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COMBINED EIP: NORMALIZER
Integration architectures with Camel and Quarkus 18
¢ Purpose: Normalize messages that are
semantically equivalent to process them
uniformly
¢ Basic EIP:
¢ Message Router
¢ Message Translator
¢ Messages arrive each in a different format
¢ Depending on the format a message is
forwarded to a specific translator
¢ Normalized messages are published on the
outbound pipe for further processing
Source:
https://www.enterpriseintegrationpatterns.com/patterns/messaging/Normalizer.html

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APACHE CAMEL
03

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WHAT IS CAMEL?
Integration architectures with Camel and Quarkus 20
Apache Camel is a
powerful Open Source
Integration Framework
based on
Enterprise Integration Patterns.

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CAMEL FACTS
Integration architectures with Camel and Quarkus 21
¢ Use the latests LTS JDK (17)
¢ Camel has also LTS versions (latest LTS: 3.21.x and 4.0.x)
¢ Latest version is Camel 4.2.0
¢ Migrate from javax -> jakarta (JEE 10)
¢ Java 17 minimum, also supports Java 21
¢ Spring Framework 6
¢ Spring Boot 3
¢ Quarkus 3
¢ GitHub statistics:
¢ 5.1k stars
¢ 238 Releases
¢ 1k+ Contributers

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APACHE CAMEL HIGH LEVEL ARCHITECTURAL OVERVIEW
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CORE CONCEPT: ROUTE
Integration architectures with Camel and Quarkus 23
¢ Routes decouple clients from servers, and
producers from consumers
¢ Provide a flexible way to implement message
processing logic
¢ Allow independent development of clients
and servers
¢ Allow for clients of servers to be stubbed
out for testing purposes
¢ Partially influence/change routing behavior at
deploy time (if components are available)
¢ Multiple Route DSLs available (XML, Java,
Yaml, Groovy, Kotlin)

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THE CAMEL (JAVA) DSL
Integration architectures with Camel and Quarkus 24
¢ Route DSL
¢ from / to / toD
¢ validate()
¢ pipeline() / routingSlip() /
dynamicRouter()
¢ multicast() / recipientList()
¢ choice().when().otherwise():
CBR
¢ process() / transform() / bean:
calling processors
¢ split() / aggregate()
¢ marshal() / unmarshal()
¢ filter()
¢ stop()
¢ loop()
¢ transacted()
¢ log()
¢ onException()
/deadLetterChannel()
¢ doTry() / doCatch()
¢ enrich() / pollEnrich()
¢ throttle()
¢ And more (messageHistory(),
sample(), wireTap(), delay(),
loadBalance(), circuitBreaker(),
serviceCall(), saga(),
claimCheck(), sort(), step(),
thread(), resequencer())
¢ Rest DSL: defining rest
endpoints
¢ Dataformat DSL
¢ dataformat()
¢ csv() / json() / xml()
¢ Component DSL
¢ Endpoint DSL

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EXAMPLE: SIMPLEST POSSIBLE ROUTE
Integration architectures with Camel and Quarkus 25
¢ Route consists of endpoints (to/from)
¢ Has a routeId
¢ Can have a description
from("file:/tmp/example/in").routeId("example01").to("file:/tmp/example/out");
from("file:/tmp/example/in")
.routeId("example01")
.description(“move files from inbox to outbox")
.to("file:/tmp/example/out")

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ROUTES: TRANSFORMING MESSAGES USING PROCESSORS
Integration architectures with Camel and Quarkus 26
¢ Processors connect endpoints
¢ Used for consuming messages, transforming messages, and implement other use-cases
¢ Are called in a pipeline (one after another) per default (making pipeline() dsl unnecessary)
from("direct:example02").routeId("example02")
.pipeline()
.log("p1: ${body}")
.process(e -> { e.getMessage().setBody(e.getMessage().getBody() + ":added"); })
.log("p2: ${body}")
.end().to("log:demo?plain=true");
from("direct:example02").routeId("example02")
.log("p1: ${body}")
.process(e -> { e.getMessage().setBody(e.getMessage().getBody() + ":added"); })
.log("p2: ${body}")
.to("log:demo?plain=true");

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DOCUMENT ROUTES USING EIP DESCRIPTION NOTATION
Integration architectures with Camel and Quarkus 27
¢ For further details visit https://www.enterpriseintegrationpatterns.com/
¢ Message as such is in the focus
¢ Concentrate on the important aspects and applied EIPs

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MESSAGE AND EXCHANGE
Integration architectures with Camel and Quarkus 28
¢ An exchange covers the interaction with the
routing engine
¢ Can have properties (a map)
¢ Or special attributes (failed, exception,
transacted, rollbackOnly, fromRouteId,
exchangeId)
¢ The exchange contains a message
¢ A Message has headers
¢ And special attributes (messageId,
messageTimestamp)
¢ Camel is all about on creating, routing and
transforming messages
Exchange
Properties
Message
Headers
Body

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MULTICAST: SAME MESSAGE TO MULTIPLE ENDPOINTS
Integration architectures with Camel and Quarkus 29
[ Test worker] example03 INFO p1: example03
[ Test worker] example03 INFO p2: example03
[ Test worker] demo INFO example03
§ Message routed to the last endpoint is the result of the result of the last processor in the
multicast.
§ Order matters, but is deterministic, because endpoints are called sequentially
from("direct:example03").routeId("example03")
.multicast()
.log("p1: ${body}")
.process(e -> { e.getMessage().setBody(e.getMessage().getBody() + ":added"); })
.log("p2: ${body}")
.end().to("log:demo?plain=true");

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MULTICAST: ORDER MATTERS
Integration architectures with Camel and Quarkus 30
[ Test worker] example03a INFO p1: example03a
[ Test worker] example03a INFO p2: example03a
[ Test worker] demo INFO example03a:added
If you want to work on the results, you should define an AggregationStrategy (later lab04)
from("direct:example03a").routeId("example03a")
.multicast()
.log("p1: ${body}")
.log("p2: ${body}")
.process(e -> { e.getMessage().setBody(e.getMessage().getBody() + ":added"); })
.end().to("log:demo?plain=true");

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MULTICAST: PARALLELIZING
Integration architectures with Camel and Quarkus 31
[(lab_01) thread #6 - Multicast] example04 INFO p2: example04
[(lab_01) thread #2 - Multicast] example04 INFO p1: example04
[(lab_01) thread #2 - Multicast] demo INFO example04
(lab_01) thread #2 - Multicast] example04 INFO p1: example04
[(lab_01) thread #6 - Multicast] example04 INFO p2: example04
[(lab_01) thread #6 - Multicast] demo INFO example04
from("direct:example04").routeId("example04")
.multicast().parallelProcessing()
.log("p1: ${body}")
.process(e -> { e.getMessage().setBody(e.getMessage().getBody() + ":added"); })
.log("p2: ${body}")
.end().to("log:demo?plain=true");

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COMPONENTS
Integration architectures with Camel and Quarkus 32
¢ Different types
¢ Consumers (from)
¢ Producers (to)
¢ Or both
¢ Core: 24 in 21 jar artifacts (4.0-M2)
¢ Non-core: 302 in 238 (4.0-M2)
¢ No need to know all non-core components
¢ You need to know there is a lot to use…
before implementing your own
¢ Many components to provide connectivity
and solutions to different problems
¢ You do not need to know all, but understand
the most relevant ones
¢ File
¢ Database Connectivity (SQL / JPA / Jooq)
¢ Messaging (Kafka, JMS)
¢ REST endpoints and clients
¢ See: list of core components
https://camel.apache.org/components/3.20.x/
index.html

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Integration architectures with Camel and Quarkus 33
QUARKUS & APACHE CAMEL
04

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WHAT IS QUARKUS?
Integration architectures with Camel and Quarkus 34
A Kubernetes Native Java stack
tailored for OpenJDK HotSpot and
GraalVM, crafted from the best-of-
breed Java libraries and standards.

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QUARKUS FACTS
Integration architectures with Camel and Quarkus 35
¢ Supports Java 11, 17 and 21
¢ GraalVM Support
¢ Current version: Quarkus 3.5.x, current LTS release: Quarkus 3.2.x
¢ Characteristics:
¢ Container-first mindset
¢ Reactive
¢ Kubernetes-native framework
¢ Build upon standards (Jakarta EE, Microprofile, OpenTelemetry)
¢ GitHub statistics:
¢ 12.6k stars
¢ 273 Releases
¢ 873 Contributors

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QUARKUS & APACHE CAMEL
Integration architectures with Camel and Quarkus 36
¢ Best from two worlds
¢ Rich integration capabilities of Apache Camel
¢ Strengths of the Quarkus runtime
¢ Build Cloud-native integration solutions
Source: https://camel.apache.org/camel-quarkus/3.5.x/

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Integration architectures with Camel and Quarkus 37
CONCLUSION
05

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CAMEL AND QUARKUS: A MATCH MADE IN HEAVEN FOR CLOUD-
NATIVE INTEGRATION SOLUTIONS!
Integration architectures with Camel and Quarkus 38
¢ Without understanding the basic concepts it is harder to dig into Apache Camel
¢ Grown framework
¢ Rich functionalities
¢ A great ecosystem of components (which may be scary for newbies)
¢ Quarkus is a great runtime to efficiently bring Camel to Containers (Spring Boot as an
alternative)
¢ Easy to get started
¢ Good documentation
¢ Proven frameworks with an active community
¢ Combination of both frameworks provides great flexibility and productivity

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WHAT WE LEARNED?
Integration architectures with Camel and Quarkus 39
¢ Camel helps to consistently implement
Enterprise Integration Patterns
¢ Camel is about routing messages

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Q & A

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SOME HELPFUL REFERENCES
Integration architectures with Camel and Quarkus 41

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INTEGRATION IS THE FOUNDATION FOR IT-MODERNIZATION
Integration architectures with Camel and Quarkus
Sven Bernhardt
Chief Architect
sven.bernhardt@opitz-
consulting.com
www.opitz-consulting.com
Thanks for your attention!
Questions left? Contact me!
42