JFall 2016 - Writeup

“Knowledge is the only treasure that increases when you share.”

- African saying.

This blog post is my writeup and evaluation of the sessions I attended at J-Fall 2016¹.

CQRS and Event Sourcing with Lagom

Unfortunately I was rather late in attending this seminar. It caused me some problems with understanding the matter. I gather it is about event sourcing and CQRS with Lagom.

Hands-on Lab: 12 things you can do better with Java8 - Jakub Marchwicki

Wow, there was a severe shortage of places to sit (properly) and headphones. He provided a github repo². I decided to leave early because of these issues. I hope to get some info from the github repo.

Sharing 2 years experience using Scala in a real project by a Java team

It did mean I could attend this session for a bit. Unfortunately, my knowledge of Scala is limited, but it was possible to follow the talk, except for the details.

Though there are some rumours that the takeoff of Scala isn't as big as it once was, the real project proved that with excellent programmers you can build a better application in Scala than in Java.

It does take some serious getting used to, though.

Java9 and the impact on Maven projects

A bit dull. Seems there are only a few little problems with using Java 9. Big problems were fixed right quickly.

Note: new jar format, special classes for different JDKs in different directories. src/main/java8 src/main/java9 etc. This is called Forward compatibility.

Modularity dependencies are hard.

Java - The Ecosystem Awakens

Sharat Shander mentioned that Java is now 21 years old already. The three top (new!) speakers of Jfall 2016 are invited to JavaOne.

Rise of the Machines - Automate your development

Sven Peters, Atlassian Evangelist, had a very entertaining seminar about Bots in Software development in general, and how they can make our lives easier. It all started with the advent of Hudson, the automated building environment, if I may call it that.

Coding Bots

JIRA should follow our versioning systems "Don't branch from a red branch". "Invite right reviewers" "Two approvals minimum before merge is possible"

Test Bots

Developers don't write bad code on purpose -> Developers are trying to solve problems. Calling Dr. Code -> Hall of Shame/Hall of Fame Hallelujah - Functional Test RunManager Flaky Test Detector -> test in Quarantaine -> create issue

Ops Bots

No more throwing stuff over the wall pagerduty : Faster feedback loop Own your code -> from end to end

Service Bots

Hercules -> scans (log) files and has system knowledge. Confluence has machinereadable bit for hercules. Hercules suggests that page. Hercules learns from response of user/firstlinesupport.

Robots can only do so much. They are very good at automating simple tasks.

Creating customer value is an art, however, and is hard to automate. Therefore humans will always be required.

Treat your bots well.

Delivering Better and Faster Microservices and Mobile Apps with the Cloud

Bruno Borges was very engaging in telling the tale. A shame that the Technology in the room didn't actually help, especially the wireless.

Software helps companies to Innovate.

Oracle has a presence on github⁵.

Documentation avoidance for developers - Peter Hilton

Peter Hilton³ was tremendously entertaining in explaining how we can write as little documentation as possible, and get away with it.

The half life of a team is 3.1 years. After that period, half your team has moved on to something else, and the knowledge they have is gone. This in stark contrast to code, which has a half life of about 15 years.

What you need is constructive laziness, which means thinking hard on how to do as little as possible.

Excuses may help, things like "It's on the Wiki". Tell a person who is leaving the team to write everything down before he's gone doesn't work. But asking questions and posting the answers into a wiki will help.

Pair programming works. A person who writes horrible/complex code will write horrible/complex documentation.

Better naming and type safety helps.

Spotify and Github have a very well documented API.

A good term is "minimum viable documentation".

Java EE Next

David Delabassee mentioned the release deadlines for Java EE 8 (2017) and Java EE 9 (2018).

They seem to be more geared towards microservices and asynchronous behaviour.

JAX-RS 2.1

server sent events

Servlet 4.0

HTTP/2 drop-in replacement server push

CDI 2.0

more geared towards outside an application server

JDF 2.3

small changes

JSON-B 1.0

JAXB for JSON.

References

[1] J-Fall 2016

http://www.nljug.org/jfall/2016/

[2] GitHub.com - JFall Java 8 Lab

https://github.com/kubamarchwicki/jfall-java8-lab

[3] Peter Hilton

http://hilton.org.uk

[4] Tom Preston-Werner - Readme driven development

http://tom.preston-werner.com/2010/08/23/readme-driven-development.html

[5] GitHub - Oracle

https://github.com/oracle