Happy Book Birthday! OCP Java 11 Practice Tests Now Shipping!

Jeanne and I are ecstatic to announce our new book, OCP Java 11 Practice Tests, is now shipping! It’s the first book in print custom written for the new 1Z0-819 Java 11 Certification Exam as well as the 1Z0-817 Java 11 Upgrade Exam.

Want to become Java 11 Certified but not sure where to start? Purchase our new Java 11 Practice Tests book along with our Java 11 Complete Study Guide, now available as The Java 11 Complete Certification Kit. While Oracle restructured the 1Z0-815 and 1Z0-816 Exams into the 1Z0-819 Exam, the material is almost identical (see this post for more details), making the Java 11 Complete Study Guide along with our new Java 11 Practice Tests Book the best source of material for learning everything you need to become a Java 11 Certified Professional!

Like our previous books, we will post any updates or notes on this blog’s Java 11 Practice Tests Book page.

A special thanks to all of our friends and family that helped write this book in the midst of the global pandemic. It’s been a challenging year and we couldn’t have done it without your support!

Switching your Gradle builds from JCenter to Maven Central

JCenter is being decommissioned on May 1st, 2021. Since many Gradle builds use JCenter by default, this means your Gradle build file is likely to have jcenter() in it. This means you have a few months to switch to Maven Central. Don’t worry, it’s easy.

Note: If you work for a company, you are hopefully using an internal binary repository proxy. (ex: Nexus, Artifactory, etc)

What’s the difference between JCenter and Maven Central?

The main benefits of JCenter are:

  • Some artifacts are in JCenter and not Maven Central – their authors are working on moving them to Maven Central. This is unlikely to affect FRC teams, but might affect people using an artifact that is more specialized.
  • It’s easier to publish to JCenter – Sonatype has been working on making it easier for Maven Central. Some of that is intrinsic though because Sonatype does a lot of verification.
  • JCenter is faster – Remember that artifacts are cached on your machine. So once you’ve downloaded the artifacts, your build performance is the same.

How do I find the affected files in GitHub?

Searching on github for either of these does not do what you might expect

  • jcenter user:boyarsky filename:build.gradle- the code tab returns 0 results
  • jcenter org:stuypulse filename:build.gradle – the code tab returns 2 results

That’s because github search only looks in files that have been updated or returned in search results in the past year. Unfortunately, the last year has not been particularly representative of a normal year. And people edit/search the contents of build.gradle files way less frequently than other file types.

I recommend just searching for the filename. That returns all your build.gradle files so you can edit them. (And since you are probably consistent in your choice of binary repository, you can sample a few matches to see if you have to change.

  • user:boyarsky filename:build.gradle – the code tab returns 5 results
  • org:stuypulse filename:build.gradle – the code tab returns 24 results

Tip: You may also have a reference to jcenter in your settings.gradle so I recommend searching that as well.

How do I edit the file?

GitHub has good Rest APIs so you can script this if you have a lot. If you don’t have a ton, either of the following is viable. (I had 5 build.gradle files in my personal repo and 3 of them were already using Maven)

Option 1 – Use the browser

  1. Open each link from the code tab of the search
  2. Choose the default branch (ex: main/master) from the pull down – search often returns a specific commit
  3. Drill down to the build.gradle file if not already there.
  4. Click the edit/pencil icon in the top right (just above the code)
  5. Change jcenter() to mavenCentral()
  6. Enter a commit comment and save
  7. If you want to make sure your build still works, run it (ex: Travis)

Option 2 – Clone the repos

(Tested on Mac; I don’t have Git Bash on my home computer so don’t know if it works exactly the same. I have used find on Git Bash though so I think it does)

  1. Clone the affected repos (if you don’t already have them)
  2. Go to a parent directory of the github repos (ex: <userHome>/git
  3. Run a UNIX command to update the list files find . -name build.gradle
  4. Run a UNIX command to update the affected files: find . -name build.gradle -exec sed -i ” -e ‘s/jcenter/mavenCentral/g’ {} \;
  5. Commit/push the affected repos (listed in step 3)
  6. If you want to make sure your build still works, run it (ex: ./gradlew build)

streamyard, virtual backgrounds, and room dividers

I live in a studio apartment. That means quite a bit of stuff is visible from my computer camera. As you might imagine, I’m a bit fan of virtual backgrounds. For work, it is easier. It’s not a problem if my co-workers see my work stuff, I don’t care if they see my mess and seeing a place that isn’t ideal for work just shares the message that I’m not enjoying my working from home full time here.

For non-work, it’s even harder. I have a nice spot for my personal machine/desk. I didn’t have a good spot for my work machine/documents. I wound up using the “empty” path that is right behind my personal computer. (Empty is in quotes because I used to do physical projects, store things there, dump them as I walked in, etc)

This means that the camera on my personal machine has a great view of all my work stuff. For JChampions Conf, I’m moderating a few sessions. Streamyard doesn’t have virtual backgrounds (unless you have an actual green or blue screen.) I don’t know how much I’ll be on camera if at all. But I won’t know until the day of. This leaves me with some inconvenient choices.

  1. Put away my work stuff. That’s problematic as some of the sessions I’m moderating are adjacent too or in between work hours.
  2. Move my personal laptop elsewhere. That’s awkward because I have two monitors, a proper keyboard, etc at my personal desk. Moving to the couch or my bed is not going to be comfortable.
  3. Turn off my video and be audio only. The default image is a blank circle. That looks terrible. (I don’t know how to upload a photo instead. And it’s a shared account so I wouldn’t even if i could.)
  4. Use a physical barrier. I own a room divider so I dragged it behind me. It’s annoying to set it up and leaves a crack of orange (the wall). But it does hide the stuff. I actually thought about using it to block off my work area so I wouldn’t see it constantly. But it comes with a limitation. I have a width of 14 inches to get to my personal computer and a width of 13 inches to get to my work machine when it is setup. Which means I’m not leaving it up and will need to set it up each of the four days. (The width of a human shoulder to shoulder is typically larger than 13-14 inches so I have to turn sideways to move around my apartment when this is setup.