This document provides information about HUJAK, a Croatian organization that promotes Java and software development. It discusses HUJAK's role in organizing Java conferences in Croatia, supporting STEM education for children, and connecting Java developers. It also summarizes Java's continued popularity and growth, and outlines some of the upcoming projects that aim to further develop the Java programming language.

1. dr. sc. Branko Mihaljević
and
Aleksander Radovan
HUJAK
www.hujak.hr 1
Java in Croatia
and HUJAK
Welcome to Javantura v6!
HUJAK - B. Mihaljević and A. Radovan

2. Before we start – some Javantura info
• General info at javantura.org
• Latest schedule at javantura.com/schedule
• On social networks you can use #Javanturav6
• Halls A/B – this one; after split at noon – Hall A is on the right, Hall B is on the left
• Hall C – on the first floor, upstairs and left from the elevators
• Lunch – upstairs
• Conference closing (with some prizes) at 6 pm
• After that we can go for a drinkup ;-)
• Javantura v6 post-conference survey will be sent to your email
Thank you all for coming today! ☺
www.hujak.hr 2HUJAK - B. Mihaljević and A. Radovan

3. Javantura v6 sponsors
www.hujak.hr HUJAK - B. Mihaljević and A. Radovan 3
Thank you!

4. What/who is HUJAK?
HUJAK is…
YOU!!!
www.hujak.hr 4HUJAK - B. Mihaljević and A. Radovan

5. HUJAK members ☺
www.hujak.hr HUJAK - B. Mihaljević and A. Radovan 5

6. What is HUJAK doing?
• Trying to connect people that like software development and (mostly) Java
• Organizing Java-related conferences and other gatherings
• Helping our members to find developers, partners and clients
• Popularizing programming and software development
• Helping in STEM reachout to children and younger students
• Popularizing Java among students and developers
• Many other things…
www.hujak.hr 6HUJAK - B. Mihaljević and A. Radovan

7. A few nice things happened in 2018…
• Java Zagreb meetups – many great meetups so far
• Java in high schools initiative with Oracle Academy
• Croatian Makers league (IRIM) continues
• Micro:bit, Logo, mBot, Scratch, Arduino, Little Bits…
• Digital Academy (Algebra)
• ScratchJr, RunMarco, Studio Code, Play Lab, Scratch, App studio,
micro:bit, Arduino…
• Code Club Croatia (Programerko & STEMI)
• Udruga za darovitu djecu "Dar" and many many others
• Two great Javantura and JavaCro conferences ☺
www.hujak.hr 7HUJAK - B. Mihaljević and A. Radovan

8. Calendar of Java-related Conferences in EU
• HUJAK's conference calendar is
available at: hujak.hr/kalendar/
• Take a look at May 2019
• P.S. If we are missing some
event please send email to
info (at) hujak.hr
www.hujak.hr 8HUJAK - B. Mihaljević and A. Radovan

9. Java-related Conferences in Croatia
www.hujak.hr 9
Conference Location Date Sessions Tracks Attendees Countries
HrOUG 2018 Rovinj 16.-19.10.2018. 70 7 370 -
JavaCro'18 Rovinj 7.-9.5.2018. 47 5 300 15
Javantura v5 Zagreb 17.2.2018. 26 3 300 -
JavaCro'17 Rovinj 10.-12.5.2017. 50 5 280 15
Javantura v4 Zagreb 11.2.2017. 27 3 300 -
HrOUG 2016 Rovinj 18.-22.10.2016. 7 (od 96) 1 (od 9) 450 11
JavaCro'16 Rovinj 18.-20.5.2016. 56 5 260 15
Javantura v3 Zagreb 20.2.2016. 23 - 300 -
JavaCro'15 Rovinj 10.-12.5.2015. 46 5 200 11
Javantura v2 Zagreb 15.11.2014. 16 - 160 -
JavaCro'14 Poreč 11.-13.5.2014. 50 5 220 11
Javantura v1 Zagreb 22.2.2014. 12 - 150 -
WebCamp 2013 Zagreb 26.10.2013. 24 - 600 -
HrOUG 2013 Rovinj 15.-19.10.2013. 11 (od 90) 1 (od 7) 370 12
JavaCro'13 Tuhelj 3.-5.6.2013. 50 5 200 -
HrOUG 2012 Rovinj 16.-20.10.2012. 11 (od 114) 1 (od 7) 370 13
WebCamp 2012 Zagreb 24.11.2012. 24 - -
Java 2012 Tuhelj 29.-30.5.2012. 34 7 170 -
HrOUG 2011 Rovinj 18.-22.10.2011. 12 (od 96) 1 (od 9) 460 11
This is our 20th conference!!! ☺
#Javantura #JavaCro #HrOUG #proud
HUJAK - B. Mihaljević and A. Radovan

10. 170
200
150
220
160
220
280
260
300
280
300 300 300
34
50
12
50
16
46
23
56
27
50
26
47
28
0
20
40
60
80
100
120
140
0
50
100
150
200
250
300
350
Sessions
Attendees
20 conferences in 7 years and we are still there ☺
www.hujak.hr 10
JavaCro and Javantura
conferences in numbers
HUJAK - B. Mihaljević and A. Radovan

11. JavaCro conferences – 2012-2018
11www.hujak.hr HUJAK - B. Mihaljević and A. Radovan

12. Javantura conferences – 2014-2018
www.hujak.hr 12HUJAK - B. Mihaljević and A. Radovan

13. Conferences HUJAK supports
www.hujak.hr 13HUJAK - B. Mihaljević and A. Radovan

14. Partners & Friends
www.hujak.hr 14HUJAK - B. Mihaljević and A. Radovan

15. "Moving Java Forward Faster"
• "For Java to remain competitive it must not just continue to move forward
—it must move forward faster." Mark Reinhold
www.hujak.hr 15
20191995 1998 2001 2004 2007 2010 20222016
2018-03-20
2017-09-21
2014-03-18
Java EE 7
2013-06-12
HUJAK
2011-12-132011-07-28
Java EE 6
2009-12-10
Java SE 6
Mustang
2006-12-11
Java EE 5
2006-05-11
Java 5
J2SE 5.0
Tiger
2004-10-04
J2EE 1.4
2003-11-11
Java 1.4
J2SE 1.4
Merlin
2002-02-06
J2EE 1.3
2001-09-24
Java 1.3
J2SE 1.3
Kestrel
2000-05-08
J2EE 1.2
1999-12-12
Java 1.2
J2SE 1.2
Playground
1998-12-08
JPE
Java
Professional
Edition
1998-05
Java 1.1
JDK 1.1
1997-02-19
Java 1
JDK 1.0
Oak
Java
JDK
Alpha-
Beta
1995
© 2018, HUJAK
2010-01-27
Java SE 7
Dolphin
Java SE 8
Spider
Java EE 8
2017-09-21
2013
1996-01-23
2018-09-25
2019-03
2019-09
2020-03
2020-09
2021-03
2021-09
Jakarta EE
Eclipse
Foundation
HUJAK - B. Mihaljević and A. Radovan

16. • #1 Development Platform
• Continued growth of Java for 23 years
• A Few Dozen Billion Devices run Java
• 10 Million Java Developers in the world
• Many have Java Certificates
• But not only Java – 50+ JVM languages
• including Clojure, Groovy, Scala, JRuby, Jython, Fantom, Kotlin, Ceylon, Xtend, X10,
LuaJ, Golo, Frege, Mirah, Eta… and JavaScript
So, what is Java … for us?
www.hujak.hr 16HUJAK - B. Mihaljević and A. Radovan

17. How is Java currently holding?
• TIOBE index for February 2019
www.hujak.hr 17HUJAK - B. Mihaljević and A. Radovan
Rank Language Ratings
1 Java 15.876%
2 C 12.424%
3 Python 7.574%
4 C++ 7.444%
5 VB .NET 7.095%

18. What about trends?
• Google Trends
• Java vs Python vs C vs C++ vs JavaScript
www.hujak.hr HUJAK - B. Mihaljević and A. Radovan 18
Average
Last 14 years
Last year (2018)

19. What about Java download?
• When you type "Java
download" in Google
you'll probably get
www.java.com
• Where you can
download JRE
Java 8 Update 201
• What about the latest
JDK download(s)?
www.hujak.hr 19HUJAK - B. Mihaljević and A. Radovan

20. Available JDKs (and Licenses)
• Oracle JDK www.oracle.com/technetwork/java/javase/downloads/
• Oracle Binary Code License (BCL) with FoU (Field of Use) restrictions $$$ ?
• Many OpenJDKs:
• Oracle OpenJDK jdk.java.net/11/
• GNU General Public License version 2, with the Classpath Exception (GPLv2cpe) with no restrictions
• Security and bug fix updates every (and only for) six months (until next JDK, no overlap)
• AdoptOpenJDK's OpenJDK adoptopenjdk.net
• OpenJDK 8 or OpenJDK 11 (both with LTS)
• Hotspot JVM or OpenJ9 JVM (former IBM commercial JVM, open-sourced to Eclipse foundation)
• Azul's Zulu OpenJDK www.azul.com/downloads/zulu/
• From JDK 6 to JDK 11, wide platform support (Windows, Linux, macOS…)
• Others: Amazon's Corretto OpenJDK, RedHat's OpenJDK, SAP's SapMachine OpenJDK,
Linux distribution's OpenJDKs …
www.hujak.hr 20HUJAK - B. Mihaljević and A. Radovan

21. • Oracle's Java SE Downloads
• Currently available downloads
of Oracle's JDK:
• Java SE 11.0.2
• Java SE 8u201
www.hujak.hr 21
Java Download
HUJAK - B. Mihaljević and A. Radovan

22. Open Sourcing and Converged Binaries
• No functional difference between OpenJDK and Oracle JDK in JDK 11+
• Open sourcing most of the closed-source parts of JDK
• Flight recorder, Mission control …
• Removing some closed-source parts
• Browser Plugin, Java Web Start,
JavaFX …
• Backwards Compatibility
• Applications depending on
Java SE should work
www.hujak.hr 22
Oracle
JDK 10
OpenJDK
10
Java SE
10
OpenJDK &
Oracle JDK
11+
Java SE
11+
HUJAK - B. Mihaljević and A. Radovan

23. OpenJDK Release Model
• New Features included (only) when ready
• Feature release versions released every 6 months (in March and
September)
• Update releases shipped quarterly (in January, April, July, and October)
• Long-term support (LTS) feature release every 3 years
• Starting with JDK 11 (September 2018), updates available for at least 3 years
• LTS for all releases is not practical
• Starting with JDK 11 (September 2018), then JDK 17 (September 2021), then JDK
23…
• For Oracle's commercial customers updates available for at least 3 years or longer
• JDK 12 – in General Availability on March 19, 2019
www.hujak.hr 23HUJAK - B. Mihaljević and A. Radovan

24. Is Java still "Free"?
• $free as in free beer (the cost) vs free as in free speech (what can you do)
• For $free use of OpenJDK binaries
• For free use of OpenJDK with GPLv2+CE license
• Updates refers to code patches – typically $free
• Support means fixing bugs and answering questions – was never $free
• LTS release every 3 years – does not mean 3 years of $free updates
• Oracle JDK 11 (and onward) can only be used in production with commercial
Java SE subscription
• Free JDK 11 (and later) are only OpenJDK binaries
• However, Oracle JDK 8 can be used indefinitely for free
• Without any further security patches and bug fixes
www.hujak.hr 24HUJAK - B. Mihaljević and A. Radovan

25. OK, but what do we use in reality?
• JVM Ecosystem Report 2018 by Snyk and Java Magazine, October 2018
snyk.io/blog/jvm-ecosystem-report-2018
www.hujak.hr 25HUJAK - B. Mihaljević and A. Radovan

26. Which Java SE version in production?
• Which Java SE version do you use in production for your main application?
• Note:
This was
before
Java 11
www.hujak.hr 26HUJAK - B. Mihaljević and A. Radovan

27. Which JDKs are in production?
• Which Java vendor’s JDK do you use in production for main applications?
www.hujak.hr 27
Source: JVM Ecosystem Report, Snyk, 2018, https://snyk.io/blog/jvm-ecosystem-report-2018/
HUJAK - B. Mihaljević and A. Radovan

28. Which Java SE version in the future?
• How do you plan to respond to Java’s new release cycle?
www.hujak.hr 28HUJAK - B. Mihaljević and A. Radovan

29. What is our advice?
• Obviously – use Java 11 ☺
• OpenJDK or Oracle JDK or any other –
it's up to you
www.hujak.hr HUJAK - B. Mihaljević and A. Radovan 29

30. More Long-term Java Future
• Project Amber – incubator for smaller, productivity-oriented language features and
simplifying syntax
• Local variable type inference, local variable syntax for lambdas, lambda leftovers, raw string literals,
pattern matching, switch expressions…
• Project Valhalla – incubator project for advanced JVM and language feature candidates
• Value types and specialized generics
• Project Panama – to interconnect JVM and native code
• Foreign function interface (FFI) as a replacement for JNI
• Project Loom – to reduce complexity in writing concurrent applications
• Fibres (JVM-level threads) and continuations
• Project Metropolis – JVM re-written in Java, i.e. "Java on Java"
• Using Graal experience, easier porting, performance to be explored (AOT compiler)
• Project Skara – alternative SCM & code review for JDK
• Git instead of Mercurial
www.hujak.hr 30HUJAK - B. Mihaljević and A. Radovan

31. Is Java really "Moving Forward Faster"?
• Community opinion: well… yeah! ☺
• Much more frequent Java releases
• Faster access to new features
• Many new improvement ideas
• A lot of maintenance and housekeeping
• Java still remains free
• However, there is no more JavaOne conference?!
• There is and it is larger than ever, but with a new name
Oracle Code One – a conference for all developers
www.hujak.hr 31HUJAK - B. Mihaljević and A. Radovan

32. Where can you learn Java?
• On every major university in the world
• On all major online learning and MOOC platforms
www.hujak.hr HUJAK - B. Mihaljević and A. Radovan 32
&

33. How can you (and your kids) start?
• Scratch (7-16 g.) i ScratchJr (5-7 g.)
• scratch.mit.edu, MIT Media Lab
• Alice (11-18 g.)
• www.alice.org, Carnegie Mellon University
• Greenfoot (13-20+ g.)
• www.greenfoot.org, University of Kent
• BlueJ (15-20+ g.) and jGRASP
• Eclipse, IntelliJ IDEA, NetBeans …
• Other: robotics, Minecraft, Raspberry Pi…
www.hujak.hr HUJAK - B. Mihaljević and A. Radovan 33

34. However, the most interesting are… robots!
www.hujak.hr HUJAK - B. Mihaljević and A. Radovan 34
Photo from Javantura v3 conference, author Johan Janssen

35. What about learning Java in Croatia?
• You can learn Java practically in each and every computing / computer science /
information technology university and/or college study program in Croatia
• Java is #1 introductory programming language for decades! ☺
• In 18 cities: Bjelovar, Čakovec, Dubrovnik, Krapina,
Križevci, Osijek, Pula, Rijeka, Sisak, Split, Šibenik,
Varaždin, Velika Gorica, Virovitica, Zabok, Zadar,
Zagreb, and Zaprešić
• On 37 or more educational institutions including
7 public universities and 15 private colleges
• In 80 or more educational programs
(BS, MS, spec, PhD)
www.hujak.hr HUJAK - B. Mihaljević and A. Radovan 35
Source: Gdje studirati računarstvo i informatiku u Hrvatskoj?, www.bug.hr/obrazovanje/gdje-studirati-informatiku-u-hrvatskoj-2018-4185, Bug, 2018.

36. What about getting hired?
• Do we have to tell you? Really? ☺
• Number of job offers on one famous job portal in ICT category
www.hujak.hr HUJAK - B. Mihaljević and A. Radovan 36

37. Instead of conclusion…
• OK, enough from us, there are 27 interesting talks today so…
• Let's start another great #Java adventure
Javantura v6
Warm welcome
from HUJAK
and CroDuke!
www.hujak.hr HUJAK - B. Mihaljević and A. Radovan 37