The document discusses the importance of modularity in software development, particularly within Java applications using OSGi and Apache Karaf. It highlights OSGi as the standard for Java modularity, addressing issues such as complexity, component reuse, and dynamic updates. Additionally, it outlines the features of Apache Karaf, including hot deployment, dynamic configuration, and remote access.

1. Modular Applications with
OSGi on Apache Karaf
Ioan Eugen Stan
@ieugen222
stan.ieugen@gmail.com

2. About me
● IT Consultant (Java, Architecture)
● Open Source Hacker
● Web: http://ieugen.ro/
● http://github.com/ieugen
● @ieugen222

3. Agenda
● Problem statement
● Short intro to OSGi
● Apache Karaf and OSGi universe
● Building an App
https://github.com/ieugen/java2days-20
14-osgi-karaf

4. Modularity is a big issue
● Deals with software complexity over
time
● Jigsaw - Java started from JDK-7 (start
2009)
● Has many aspects: deployment,
management, runtime

5. Why modularity?
● Reduce complexity
● Allow parallel development
● Improve component re-usability
● Upgrade proof systems

6. When Applications can Roam Freely, P. Kriens - http://slideplayer.us/slide/732791/

7. A solution for Java modularity?
Jigsaw was delayed again (does not
address dynamism)
Try OSGi – the de facto standard for
Java modularity

8. OSGi – overview
● Modular system for Java/JVM
● Service platform
● Dynamic component model

9. http://www.slideshare.net/mfrancis/osgi-technology-value-proposition-december-2013

10. OSGi Benefits
● Reduced Complexity
● Promotes Reuse
● Real World – things appear/disappear
● Dynamic updates

11. OSGi Service Gateway Architecture
Application / Bundles
Services
Service registry
Life cycle
Modules
Java Virtual Machine
Operating System
Hardware
Security
http://en.wikipedia.org/wiki/OSGi

12. OSGi Architecture (2)
Bundle 1 Bundle 2 Bundle n
System Services
e.g. Java ME CDC, SE, EE
e.g. Windows, Linux VxWorks, QNX
http://en.wikipedia.org/wiki/OSGi
C/C++
OSGi Framework
Java Runtime Environment
Operating System
Hardware
Drivers
Server Platform
JNI

13. Apache Karaf
Apache Karaf is a small OSGi based
runtime which provides a lightweight
container onto which various
components and applications can be
deployed.
http://karaf.apache.org/

14. Karaf Architecture

15. Features
● Hot deployment of bundles
● Dynamic configuration
● Provisioning of applications
● Native OS integration
● Remote Access (SSH, Web)
● ...

16. Projects
● OPS4j - https://github.com/ops4j
● OSGi JAX-RS Connector
https://github.com/hstaudacher/osgi-j
ax-rs-connector

17. Demo time

18. Thank you.
Time for questions.