Here’s a quick summary of Oracle Code One 2019, which was last week.
It essentially started the previous week at the “Chinascaria”, Steve Chin‘s Community BBQ for JUG leaders and friends. Although Steve is now at JFrog, he’s continuing the BBQ tradition. Of course Bruno Souza, Edson Yanaga, and some other cohorts from Brazil were manning the BBQ, and there was plenty of meat to be had. I didn’t get many photos, but Ruslan from JUG.RU was there and he insisted that we take a selfie:
Hi Ruslan! Oh, here’s a tweet with the chefs from the BBQ:
Java Keynote
The conference kicked off with the Java keynote, The Future of Java is Now, led by Georges Saab. The pace was pretty brisk, with several walk-on guests. We heard from Jessica Pointing talk about quantum computing, and from Aimee Lucido on her new book, Emmy in the Key of Code. This sounds really cool, a book written in Java-code-like verse. This should be interesting to my ten-year-old daughter, since she’s reading the Girls Who Code series right now. I have to say this is the first time I’ve shown a segment of a conference keynote to my family!
Naturally a good section of the keynote covered technical issues. Mikael Vidstedt and Brian Goetz ably covered the evolution of the JVM and the Java programming language. Notably, Mark Reinhold did not appear; he’s taking a break from conferences to refocus on hard technical problems.
My Sessions
This year, I had two technical sessions and a lab. This was a pretty good workload, compared with previous years where I had half a dozen sessions. I felt like I made a good contribution to the audience, but it left time for me to have conversations with colleagues (the “hallway track”) and to attend other sessions I was interested in.
My sessions were:
Collections Corner Cases — slides — video
This session covered Map’s view collections (keySet, values, entrySet) and topics regarding comparators being “inconsistent with equals.”
Local Variable Type Inference: Friend or Foe? — slides — video
(with Simon Ritter)
When Simon and I did an earlier version of this talk at another conference, we called it “Threat or Menace.” This probably doesn’t translate too well; to me, it has a 1950s red scare connotation, which is distinctly American. I think that’s why Simon changed it to Friend or Foe. It turns out that Venkat Subramaniam also had a talk on the same subject, entitled “Type Inference: Friend or Foe”!
Lambda, Streams, and Collectors Programming Laboratory — lab repository
(with Maurice Naftalin and José Paumard)
This lab continues to evolve; there are now over 100 exercises. Thanks to Maurice and José for continuing to maintain and develop the lab materials. I recalled that we first did a Lambda Lab at Devoxx UK in 2013, which was before Java 8 was released. Maurice and Richard Warburton and I got together an hour beforehand and came up with about half a dozen exercises. It was a bit ad hoc, but we managed to keep a dozen or so people busy for an hour and a half.
More recently we (mostly José) have added and reorganized the exercises, converted the project to maven, and converted the test assertions to AssertJ. I’ve finally come around to the idea that maven is the way to go. However, the lab attendees still had their fair share of configuration problems. The think the main problem is the mismatch between maven and the IDE. It’s possible to build the project on the command line using maven, but hitting the “Test” button in the IDE does some magic that doesn’t necessarily invoke maven, so it might or might not work.
One thing that was new this year was the “Meet the Experts” sessions. In the past we’d be asked to sign up for “booth duty” which consisted of standing around for a couple hours waiting for people to ask questions. This was mostly a waste of time, since we didn’t have flashy demos. Instead, we scheduled informal, half-hour time slots at a station in the Groundbreakers Hub, and these were put onto the conference program. The result was that people showed up! I signed up for two of these. I didn’t have a formal presentation; I just answered people’s questions. This seemed considerably more useful than past “booth duty.” People had good questions, and I had some good conversations.
Everything You Ever Wanted To Know About Java And Didn’t Know Whom To Ask — video
I hadn’t signed up for this session, but the day before the session, Bruno Souza corralled me (and several others) into participating in this. Essentially it’s an impromptu “ask me anything” panel. He convinced about 15 people be on the panel. This included various JUG leaders, conference speakers, and experts in various areas. During the first part of the session, Bruno gathered questions from the audience and a colleague typed them into a document that was projected on the screen. Then he called the panelists up on stage. The rest of the session was the panel picking questions and answering them. I thought this turned out quite well. People got their questions answered, we covered quite a variety of topics, and it provoked some interesting discussions.
Other Sessions of Interest
I attended a few other sessions that were quite useful. I also watched on video some of the sessions that I had missed. Here they are, in no particular order:
Robert Seacord, Serialization Vulnerabilities — video
Mike Duigou, Exceptions 2020 (slide download available)
Sergey Kuksenko, Does Java Need Value Types? Performance Perspective — video
Brian Goetz, Java Language Futures, 2019 Edition — video
Venkat Subramaniam, Type Inference: Friend or Foe? — video
Robert Scholte, Broken Build Tools and Bad Behaviors (slide download available)
Nikhil Nanivadekar, Do It Yourself: Collections
Here’s the playlist of Code One sessions that were recorded.
Unfortunately, not all of the sessions were recorded. Some of the speakers’ slide decks are available for download via the conference catalog.
Synchronous Messages 