Category Archives: Java Certification

PASSED! Jeanne’s Experience Taking the Java 25 Certification Exam 1Z0-831

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Oracle recently announced their new Java 25 Certification Exam 1Z0-831. [Yes, we are working on the certification study guide book] I took it this morning and passed with a 74% (I don’t try for a good score; I try to take it quickly after it comes out. In this case, I took it a few days after getting back from a trip to California. I only slept 5.5 hours last night (got home late from train delays). So I was a bit tired. But I passed and that’s what matters.

If you read my blog post about the Java 21 exam, you know there was significant time pressure. That is fixed on the Java 25 exam. I had sufficient time to go slowly and still had about half an hour left at the end which I could have used to review my answers. (I choose to turn it in without reviewing because I felt a little dizzy; probably from using the computer right when I woke up after insufficient sleep.)

Checking in

Oracle changed how they do exams since the Java 21 exam came out. (You saw a person as proctor.) The new system is described here and much better. I used it when taking Oracle cloud exams and it is the system in use now for the Java 25 exam. It comes with an online whiteboard.

The exam

While there were still some long questions, it was faster to read the code. It was either read some code and state the output (so only one set of code to read) or multiple answers with code where it was easier to tell the differences. Also there were less long questions so I didn’t feel time pressure.

Looking back I had 16 minutes left after the Java 21 exam. While I had more time left over here, the big difference is I went super slow this time while last time I had to rush to get that time. I knew I was tired and didn’t want to make silly mistakes.

About 5 questions took about 10 seconds to load. That feels like forever during an exam! And it was before 8am in the morning local time so it wasn’t a lot of people using the internet. I hadn’t had that problem on past exams.

For content, I got a good mix of questions spanning the objectives. Not as many Java 22-25 questions as I expected but that could be luck of the draw.

After the exam

I removed the “Secure Companion” app and Proctorio Chrome plugin. from my machine. It has a lot of power so I like it not being there.

I tried going to the CertView page to get my badge but got a 502 error. Will try again in the future. I used Chrome as Safari on Mac didn’t let me expand the menus in the past.

To see my exam details:

  • Expand “Exam Results” on left navigation
  • Click “Exam History” on left navigation
  • Click “Results” on this exam on the right side
  • This downloads a PDF showing which objectives you got a question wrong on

For credentials, expand “Credential Management” on left navigation. You can then download a certificate or badge. There are also links to post on LinkedIn or email a link to verify your credential. I then went on Linked in and added a credential including the credential URL.

java playground and jshell

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Today I learned that it looks like the Java Playground uses JShell. I knew it didn’t require a class/main method wrapper.

The reason I discovered this was because of the following code:

Consumer p = (p) -> {int var = 3; var++; return;};

In my IDE or at the command line, this code gives an error

Lambda.java:2: error: variable p is already defined in method main()
Consumer p = (p) -> {int var = 3; var++; return;};

In JShell and Java Playground, it happily compiles. This matters because I was told that the flashcards with my book has an errata and that “p” is just fine.

The Java Language specification writes about shadowing:

It is a compile-time error if the name of a formal parameter is used to declare a new variable within the body of the method, constructor, or lambda expression, unless the new variable is declared within a class or interface declaration contained by the method, constructor, or lambda expression

Lesson to readers: don’t use jshell when studying for the exam.

Happy Book Birthday! New OCP 21 Book Now Shipping!

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It's a Book!

Jeanne and I are excited to announce our new Java OCP 21 Certified Professional Study Guide is now shipping! Released by Wiley Publishing, this book teaches you all the new (and old) features of Java 21, and helps prepare those planning to take the 1Z0-830 Java 21 Certification Exam.

Are you worried your Java skills are getting outdated? Are you writing code with the same toolset you’ve been using since Java 11, Java 8, or even Java 1.4? This book is definitely for you then! It starts with the basics, incorporating all of the new languages features like pattern matching, text blocks, var, and switch expressions. After that, we add records, sealed classes, virtual threads, sequenced collections, modules, and more. Finally, we cover lambdas and streams, helping you write shorter code and easier-or-read functional code without a lot of boilerplate syntax.

Whether your fresh out of school or have been programming Java professional for over a decade, our book helps you understand how to use all of the features of Java 21. We cover each topic in detail, from the basics to advanced usage, to help you write better Java code in your daily life.

For those looking to become Java 21 certified, look no further. Our book contains 14 chapters of everything you need to prepare for the exam, including exam tips, study suggestions, and hundreds of challenging practice questions. It also includes access to Sybex’s Online Test Bank, where we’ve written 3 simulated 1Z0-830 practice tests and over 500 flashcards!

Order now for the holidays, as Amazon already has our book backordered until the second week of December!