Passing the 1Z0-819 Oracle Certified Professional Java SE 11: preparation and exam experience

In this article I’ll explain how I passed the 1Z0-819 Oracle Certified Professional Java SE 11: the level and experience I had when I decided to pass it, which mock exams I used, how I studied and trained on the different topics…

For further preparation, you can check my OCA and OCP related articles in which I covered most of the topics needed for the certification exam, with some advice and gotchas highlights. I would advise you to cross sources and always learn from various people and courses to get the most complete and accurate information.

Where I was and why I took the OCP certification as a junior developer

First I’d like to present my situation when I took the OCP certification:

• I passed the OCA Java 8 certification (associate level) a year before. The new OCP certification covers level I (ex-OCA) and level II (professional level). It means I had already worked on some topics which were covered by the OCA. However, additional topics are way harder than the ones of the OCA certification.
• I had been working in IT as a full-stack developer, mainly in Java, for a bit more than a year. My job was clearly junior level, however I think it helped and I would not advise someone with zero Java professional experience to take the OCP exam.
• I took advantage of the 6 months of free access on the beta-version of the JetBrains Academy / HyperSkill platform and had done most of the Java topics, including advanced (level II) ones like multithreading, Collections framework (not limited to ArrayList), advanced Date/Time manipulations, Nested classes… My free access finished three months before I started studying for the certification.
• I am a nerd… Every time I take a course or I do a training, I take notes and compile information in my holy notebook (or I write articles on this blog about it), that really helps consolidating the information in my head and make sure I understand it.

I took the OCP certification thanks to the Oracle 25-years offer. This gave me 2 months free access to the Java SE 11 path on the Oracle University website, and the certification cost $25 instead of $250.

I just thought “Ok, let’s give it a try, at worst I would loose 25 bucks, at best I get certified for a great price!“. They announced this on 25th of February and the certification had to be done by the 25th of April (so exactly 2 months to prepare). I directly bought my voucher and made an appointment for the 25th of April.

It was a goal for me to pass that certification, although I would probably have given it a few more months or years if it wasn’t for this time-limited rebate.

How I prepared for OCP certification exam

Oracle University

Because the Oracle University course was available for free for 2 months, I started with it. There was a 30 hours course on Java 11, which (I realized later) was not especially meant for certification takers and would cover topics not needed. The course was all video, while I’m more of a reader (hence, my preference for platforms like the JetBrains Academy), and the slides were covered with loads of text, which made it difficult to grab all information. Plus the speaker would go really fast on important topics.

From the 30 hours, I watched about 61%: I skipped almost all the guided practice videos, I skipped what I noticed wasn’t exam topics (like OCI Oracle Cloud Infrastructure related lessons), but I also often paused to read the slides before listening to the speaker.

There was a second 3-hours course dedicated to OCP certification, only covering some special topics, which was a bit more relevant but not at all complete.

Enthuware mock exams

After Oracle Academy online courses, I started the mock exams with Enthuware (which I used for OCA and helped a lot). This is about 10 bucks and totally worth it. They are timed exams with corrections and tips. That made me really depressed because I scored poorly at almost all attempts.

On the related forum (CodeRanch), the few people who gave feedback about the exam said that the level of the certification exam was really similar to the mocks of Enthuware. At that stage, there were a few days left before the certification and I was really stressed and not confident at all.

JetBrains Academy

I chose not to spend too much time on the mock exams and find other sources to learn and understand the topics. I felt the course from the Oracle Academy were not complete enough in order to pass the certification.

I luckily had a new trial period on JetBrains Academy thanks to the renewal of my student license for IntelliJ, so I retook some courses on topics I was the less confident about (multithreading and nested classes). I also did some research on the Internet for articles and Stack Overflow posts.

Pluralsight 1Z0-819 series

Then, four days before the certification, I realized that Pluralsight had a new series of courses dedicated to 1Z0-819. I guess they were really fresh because I checked a bit more than a month before and they weren’t there.

Although I found them pretty late, they helped a lot! If you’re reading this: start with them, watch them all, take notes, then test your knowledge with Enthuware, and search for additional articles or videos on weak points!

I binge watched (because I was in a hurry at this point) the most relevant, useful lessons regarding my weakest topics. Most courses were great, with summaries on important points, tips and tricks, and so on.

Back to failing Enthuware mocks

Even with the additional courses I took, I was still failing miserably at mock exams. Just like the more I knew and understood, the worst I was performing. I was sure I was gonna fail the certification. So I decided to make a session of meditation and accept what was: I was gonna fail but it didn’t matter, I just wasn’t ready yet. And I spent the morning of the certification cleaning my house to relax (totally irrelevant information, or is it?).

For information regarding Ethuware mocks, I had done the 3 start exams with very few preparation, from which I passed two, then I took 5 or 6 mid-exams which I failed around a consistent 58%, then I took one final exam after Pluralsight binge-watching which I failed with 52%, and the last exams I took were the “most-missed questions” were I passed several times with 70 to 80%… For OCA I did all mock exams and could see a clear progression, for OCP it was just a mess. Stress, maybe?

How did the OCP certification exam go

Doing the exam online at home

I had to do the exam at home because of the Covid-19 situation and the limit date (my local center was fully booked).

I had taken the OCA certification at my local center, then passed two Cloud related certifications at home. The Cloud certifications were more theoretical than programming certifications. It’s a bit uncomfortable at home because you cannot have paper, you have nothing to write, and you cannot even mutter! Iterating over N-dimensions arrays in your head is though, it’s even worse when you have to do it in silence and control the movements of your mouth… There is a virtual whiteboard during the exam which is a pain to use so you end up doing it all mentally.

Knowing that constraint, I did all the mocks without paper, to be prepared. I would really advise to take the certification exam in a local center when possible, because knowing that someone is watching you, not being allowed to mumble, look away from the screen, write… can add to the stress.

Time allowed and passing score

Regarding the constraints of the 1Z0-819 exam, passing grade is 68%, time allowed is 90 minutes and number of questions is 50. To compare, OCA was a pass at 65%, it had 70 questions and time allowance of 150 minutes. I read a lot of complaints about the allowed time being too short for the OCP. When I’m doing mocks at home I’m always pretty fast, but I remember that for OCA I finished the exam only 10 to 15 minutes before the end.

The exam itself

The first questions felt really easy, a lot of level I questions. I got a feeling that difficulty level was rising with the questions, but that might just be a result of exhaustion because questions are supposed to be totally random.

On the whole, I didn’t find many questions to be tricky, I only noticed one question where they were really trying to get you on a stupid typo* (but it’s likely that I didn’t notice some and fell for it).

The exam covers a really wide range of topics. There were questions clearly related to level I (associate level), while the mocks of Enthuware concentrate only on level II topics and are really tricky. I guess the motivation of the mocks is to get you prepared to the highest difficulty. bu then I don’t agree with those who said that difficulty level is equivalent.

I finished the exam a little 15 minutes in advance (timing seemed really alright for me). I re-read the first question, noticed I had fallen into a trap, corrected my answer, then I was too exhausted to review the rest of it and I quit. Funny enough, the exact same thing happened when I passed OCA. So always review at least your first answer!

Topics I had during the exam

Here’s what I remember:

• I got some questions on modules, security and nested classes, which are to my opinion important topics to focus on, plus the advanced Date/Time and Localization APIs.
• OOP concepts are really important too (inheritance, polymorphism, encapsulation).
• A few basic questions on loops, statements, conditions.
• I got an advanced question on Enums (can’t remember it but it made me sweat).
• Quite a lot of questions on lambdas and functional interfaces.
• Of course all other topics of the OCP were covered and the number of questions per topic is totally random so you have to be equally prepared to answer questions on all of them.

Also worth mentioning that any additional knowledge of general computer science topics like Operating Systems, File Systems, Design Patterns, tech vocabulary… is really a plus, and necessary to completely understand it all.

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So guess what, I made it! I scored lower than OCA, with 74% vs 83%, but it just makes sense as the OCP is rather high-level and might be more dedicated to medior or senior developers (Oracle’s guidelines recommend at least 1.5 years experience in developing with Java, but depending on individual experience a year of experience can be full of practice and learning or slow-paced and stationary…).

I hope I gave you some useful information on passing the OCP certification, and for topics revision have a look at the dedicated articles.

(*) The tricky question was about Resource Bundle, the trick was a typo (file name without final -s, string parameter with final -s) in the resource bundle file name when creating the Resource Bundle object.