To JAR Hell And Back

A live-coding talk where we take a typical Java 8 code base and update it to Java 9 and beyond, overcoming some common and some less common hurdles like dependencies on internal APIs and split packages

I'm sure you've heard about compatibility issues when upgrading from Java 8 to 9 and beyond, but did you try it yourself yet? This live coding session starts with a typical Java 8 application and runs up against and eventually overcomes the common hurdles:

  • build system configuration
  • dependency analysis with jdeps
  • dependencies on internal APIs and Java EE modules
  • split packages

To get the most out of this talk, you should have a good understanding of the module system basics - afterwards you will know how to approach your application's migration to Java 9 and the module system.


Here's the current version of the slides.

I also embedded them below. If they're focussed, you can navigate with arrow keys or swipes (they're two-dimensional, with chapters on the horizontal axis and chapter content layed out vertically). Use Page Up/Down for linearized order and ? for more shortcuts.


Here's a good recording of the talk. I hope you'll like it.

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Watch on YouTube

Past Presentations

I gave this talk a few times before. See below for links to slides (as they were at that very event), videos, and other information.


Wed, Jul 10th, 18:30 Europe/BerlinTo JAR Hell And Back
at JUG Darmstadt
TU Darmstadt, S2|02 (Robert-Piloty-Geb.), Raum C110, Hochschulstr. 10
Wed, Jul 3rd, 18:00 Europe/ParisTo JAR Hell And Back
at ElsassJUG
Epitech, 4 rue du Dome, Strasbourg
Thu, May 23rd, 14:10 Europe/StockholmTo JAR Hell And Back
at DevSum 2019
Stockholm, Folkets Hus, Room 307


Wed, Nov 14th, 12:00 Europe/BrusselsTo JAR Hell And Back
at Devoxx Belgium
Antwerpen, Kinepolis, Room 8
Tue, Jun 26th, 18:00 Europe/BerlinTo JAR Hell And Back
at inovex Meetup
Karlsruhe, inovex office, Ludwig-Erhard-Allee 6
Fri, Jun 8th, 11:30 Europe/TallinnTo JAR Hell And Back
at GeekOut
Tallinn, Kultuurikatel, Room 1
Fri, May 11th, 09:00 Europe/LondonTo JAR Hell And Back
at Devoxx UK
London Islington, Business Design Centre, 52 Upper Street
Tue, Feb 6th, 11:00 Europe/StockholmTo JAR Hell And Back
at Jfokus
Stockholm Waterfront Conference, Room A1
Sat, Jan 27th, 14:30 Europe/SofiaTo JAR Hell And Back


Sun, Nov 5th, 14:00 Europe/KievTo JAR Hell And Back
at JavaDay
Kiev, Convention Center “Parkovy”, Parkova road 16a, Track 1
Wed, Sep 13th, 13:00 Europe/OsloTo JAR Hell And Back
Tue, Jul 25th, 16:00 UTCTo JAR Hell And Back