speaking at the NY Java Sig and including remote attendees

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This week, I spoke at the NY Java Sig reprising my QCon Java 10/11 Release Train talk.It was fun.  Last time I spoke at the NY Java Sig, I was the unplanned “opening act” for the main talk. This time, there were two planned speakers and I was one of them. I went second.

The NY Java Sig was hosted by Credit Suisse. They had 12 remote attendees from their Raleigh, NC office. We were able to hear, but not see them. They were able to see me.

I work on a distributed team so dealing with remote people I can or can’t see is just a part of me. I didn’t realize how much so until this presentation though.

When I present, I try to involve the audience a bunch of times. They raise their hands, vote on stuff, etc. Almost every time I did that, I asked someone in Raleigh to comment on how the vote looked there.

I got feedback at from the NY Credit Suisse representative that this was the first time that a speaker included them. (To be fair, most speakers don’t involve the NY audience either.) The really cool part is that I didn’t even realize I was doing it. It was just part of me; they were attending so I asked.

For this particular presentation, I had offered a couple “free conference level training” available to any of our offices remotely. So I had practiced with people I couldn’t see as well.

var in java 10

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In my Java 10/11 talk, I ask the audience if this code compiles:

var var = "var";

I usually get about a 50/50 response. The answer is that it does compile due to backward compatibility. You could have a local variable named var and it should still work. When I gave the talk at the NY Java Sig tonight, Mark asked “what if you have a class named lower case var”. After wincing a bit at the lower case class name, I said I didn’t know. But I definitely wanted to find out.

The answer is actually pretty interesting – it depends on what version of Java you compile with!

Compiling var.java

Fierst I created a class


public class var {

  public static final String STR = "a";

}

This class compiles in Java 9 and below. It does not compile in Java 10 or 11. Instead you get the message:

as of release 10, 'var' is a restricted local variable type and cannot be used for type declarations

This means that you have to change the class name. However, you can still have a var.class file compiled in Java 9 or below.

Referencing that var.class file

Compiling OR running the code with Java 10/11 doesn’t let you refer to that var.class file either.

TripleVar.java:5: error: illegal reference to restricted type 'var'

Conclusion

If you followed bad practices and named your class var.class, you must change it. Even if you compiled in Java 9, it will not run in Java 10.

first impressions of VS Code (visual studio code)

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FIRST Robotics is using VS (Visual Studio) Code as the default IDE next year so I’ve developed a sudden interest in learning it :).

My overall impressions

It is much faster to get started with VS (Visual Studio) Code than Eclipse. And for the simplified use cases for FIRST robotics this makes sense.

Initial install

I installed it about two months ago. That was easy. I went to the website and downloaded. I didn’t have time to do anything then so my only experience was when I double clicked a .java file when preparing for my QCon Java 11 presentation. It’s a nice editor so cool that it opened out of the box. Not so cool that it changed my defaults for opening files without telling me.

Also nice that VS Code prompts with a suggestion to install the Java extension pack when I opened the Java file.

Upgrading

Since I didn’t do anything, the first order of business was to upgrade to the latest version. VS Code makes this easy. One  a Mac, you go to code > check for updates. It downloads quietly in the background. Then you go back to Code and choose restart to download.

Like Eclipse, the release notes automatically open. However, since I’m completely new to the tool, everything is new to me so I didn’t read it.

Plugins

The FIRST website suggests some plugins. To start with, I installed:

  • Java extension pack – includes the plugin for Maven
  • C++
  • WPILib – this is a custom download (vs being part of marketplace at this time).

I like that it uses a Marketplace like Eclipse. I also like that you just click “reload” to have the downloaded plugins take effect (rather than having to restart the whole IDE). I also like that the extensions menu has an install from VSIX option. Really easy to install a plugin that you downloaded from the internet.

I’ll install more plugins after getting the lay of the land.

Documentation

The VS Code getting started is good. I like that it includes the keyboard shortcuts for opening the command palette.

  • shift+command+P = mac
  • shift+ctrl+P = windows

It was harder to find the windows keyboard shortcuts than expected. The website help “knows” I’m on a Mac so tells me about the Mac ones. But I’m going to be helping students on multiple operating systems. (It was clear in the FIRST robotics docs, but I would have liked this to be clear on the Microsoft website as well)

Creating a first project

I used the WPI wizard to create a new project. It was easy to use and fast. The file structure is standard for a Gradle project so it felt familiar. I opened the Robot.java file and tried to make a change. Then VS Code started “downloading the internet.” This is also normal for Gradle. I was just expecting it to happen on file creation or first build rather than when I pressed ctrl+space for autocomplete.

I like that you can use the command palette to run commands without having to use the mouse or memorize a lot of keyboard shortcuts.

Playing a little

Many of the keyboard shortcuts are standard so autocomplete and closing tabs works as expected. If a file has warnings it (and the package name) are in green. Similarly, errors are in red. I imagine this is customizable if someone is red/green colorblind. I’m surprised the defaults are ones where this is a problem.

How to open multiple projects

I immediately wanted to compare two projects in the same workspace. This is easy. You go to file > add folder to workspace. This creates a “multi root” project.