Eric Manaois

Big congratulations!! We made it. Hard work really pays off. Whats now your plan after passing the exam?

Yeah, I agree with most of your opinion. I think this is the most difficult exam I had in my entire life considering the breadth and depth of the topics. I also don't like that we need to memorize all the command line options for javac, java, jar, jlink, jdeps, and jmod. it's not like we will be using them often like git commands.

I would also like to comment on the use of mock exams. I think it is necessary to use mock exams in any certification exam to know your knowledge gaps. That's why I did the objective-wise exam from Enthuware so I can just focus on that one topic and move on if I know I already mastered that topic. Memorizing the enthuware exam will not make you pass the exam. Because it is just in your short-term memory and I think knowing the whole concept is still far better. Even though I did memorize each exam question in Enthuware, I still forgot them after a few weeks and even my certification result is not that high.

I think the best way to study is to play with the code and try those edge case questions and those weird combinations of commands like putting null to some parameters for example: Collections.sort(list, null) where list is an ArrayList. Yeah, this is a valid command where it will sort the list regularly and not return a NullPointerException. Also, the Java documentation plays a big part if you read them. I only did this in the last weeks of my review and I think this is needed to understand those very tough questions.

Yeah, thank you. I still remember most of the questions I got wrong during the class. It was a wake-up call for me what I still lack especially that Liskov substitution topic. Speaking of waking up, I was still awake that time from 10 pm to 3 am. I was determined to pass this exam because it was so long overdue. And thank you for the class, it was a big help for me.

If you pass the mock exams consecutively then you are ready to take the exam even without comparing your score to the average Enthu scores.

Today I passed the OCP Java 17 certification. This is my 2nd take for the exam and I'm glad that I passed it this time.

I started studying during the Christmas holiday break in 2022. Yes, that was a long time ago. My company gave me an Oracle unlimited subscription which includes 5 exam vouchers for any Oracle certification. So that's why I decided to take the latest Java certification available and it took me more than a year to pass this difficult exam. On some days I am very diligent in studying but work comes in the way and breaks some of the days that became weeks, then months that I was supposed to study.

I did not use the video tutorial from Oracle as I find reading the book more enjoyable to me. I read the infamous OCP Study Guide by Scott and Jeanne on a Kindle app using my iPad. There I highlighted and took notes like crazy of all the things I currently do not know until 1st week of February. I transferred these notes to Obsidian, my note-taking app so I can easily review the notes in a summarized format. My notes include a lot of source code examples, tips, mnemonics I used to remember things and all the easily forgettable ideas. If I were to print this it may take 50-70 pages of A4 paper. I re-read the study guide once again and it took me until April to finish my 2nd reading and note-taking.

After this, I got busy at work and was not able to study for a few months.

I also used Enthuware for the mock exam and started studying again in August and used IntelliJ as my IDE for testing codes. It took me 1 month to study as my vouchers are expiring in September. And used Luka Popov's Udemy video for a quick refresher on some of the chapters. Then I took the exam and failed at 62%.

After that, I took a long break and studied again starting in January 2024. This time I used the objective-wise test of Enthuware and memorized each topic until I got a perfect score in each topic exam. I have read this strategy in one of the passers here in Code Ranch and I think this is a saver for me. So thank you for this tip

I also joined Simon Robert's March class. Overall it was helpful that I joined this class. It is good that there is a live interaction with the instructor so we can ask easily some of the harder topics. Thanks Simon for your tips.

And today I took the exam and finally passed. This was an exhausting certification study for me. I just want to get this certification for myself as I wanted this since I was in college and Java is one of my favorite subjects that time.

In the exam, there are 4-5 questions regarding modules, 3-4 questions about JDBC, a lot of concurrency questions, and also with streams. Also there is now a proctor who asks for your ID unlike months ago. They just ask for my ID and show it in the camera and they have not checked the room where I'm taking the exam.

One question that I still remember is about binary search which I got wrong and looks like this:

List<String> list = Arrays.asList("m2", "m3", "m1");   System.out.println(Collections.binarySearch(list, "m3"));         Collections.sort(list);   System.out.println(Collections.binarySearch(list, "m3"));         Collections.reverse(list);   System.out.println(Collections.binarySearch(list, "m3"));

And also I got the IO buffer question like in the enthuware:

Given that a file named test1.txt contains the following data: 0123456789 and test2.txt is non-existent

and the following code snippet:
char[] buf = new char[8]; try(FileReader fr = new FileReader("test1.txt");    FileWriter fw = new FileWriter("test2.txt")){    var count = 0;    while( (count = fr.read(buf)) != -1){        fw.write(buf);    } }
And the answer to this is: 0123456789234567

My final tip for this exam is do not stop studying and keep your momentum. You will forget some of the things you have studied once you get a break. My trick for forcing me to study is going to a nearby coffee shop and studying there (with headphones on). There I was forced to study and not be lazy just like if I'm at home (plus the coffee which makes me awake).

I'm looking forward for this crash course today

Thank you all for the explanation. I now understand that the foreach was not a terminal operation of the stream but just a chain for the returned map from the collect method.

I thought that we can only use a single terminal operation (cannot be chained) on streams.
Im not sure why does the following code compile if it has multiple terminal operation (collect, foreach)?

public class ItemCollection {    private record Item(            String name,            String category,            double price) {    }    public static void main(String[] args) {        List<Item> items = Arrays.asList(                new Item("Pen", "Stationary", 3.0),                new Item("Pencil", "Stationary", 2.0),                new Item("Eraser", "Stationary", 1.0),                new Item("Milk", "Food", 2.0),                new Item("Eggs", "Food", 3.0)        );        items.stream()                .collect(Collectors.groupingBy(Item::category))                .forEach((a,b) -> {                    double av = b.stream().collect(Collectors.averagingDouble(Item::price));                    System.out.println(a + " : " + av);                });    } }

Congratulations and good job!!

If you still have free links for the course it will help me in my studies.

Thank you.

Can anyone help me how to correct the compiler error bellow using upper bounded generics?

public static void main(String[] args) {        List<? extends Number> list = new ArrayList<Integer>();        list.add(Integer.valueOf(1));        // compiler-error        System.out.println(list.get(0)); }

I will be using my company laptop for the exam. But it has a restriction on installing new softwares. Does the exam software uses an installer for the exam, or is it a simple exe file? I plan to take the OCP17 cert.

Thank you.

Thank you for all the tips. Ill check after a month if I need to reschedule. At least now I know that my timetable is in the fast side. I just wanted to make sure that I will review everyday and would like to target the 2 months if it is possible.

For my background I’d been using Java professionally for 3 years on an Android development and now I switched to web dev. I am initially a C++ developer for 9 years then switched to Java for Android. Probably the only topics that I don't have that much experience or do not have confidence are lambdas/streams (I used the non-lambda/streams way during my development), and modules.

Fortunately I got a year of learning subscription to Oracle Learning University which comes with 5 exam vouchers and was paid by my company. I was very lucky that I got this opportunity since I just started in the company and they approved my request for a Java cert immediately. Also it is up-to us what certification we will take and how many. They don’t mind if we used our 5 vouchers on one exam. But I plan on getting SE17 now then EE7 afterwards. Then I guess after that Im done with Oracle cert. Hopefully I can only use 2 vouchers. I don't mind failing but I will target for a high score on my first try.

Also thank you for replying on my post with those tips. This helps a lot and will keep my studying momentum until the finish line.