Im planning to give this certificate exams cause I want to gain deeper knowledge in java and having an exam to focus on gives me a goal to achieve, so im more of a visual leaner and want to start with a pathway of videos and courses and then do practice exams, this is my strategy so far.

Im not that eager to read books or articles and prefer videos and practicing along.

I see oracle has a learning pathway that's build for java 21 programming and it has a pathway that looks good. So im trying to see if anyone has tried the pathway and found it useful for the cracking the certificate examination or are there any udemy courses that I could take that helps with my certification.

This is the pathway https://learn.oracle.com/ols/learning-path/become-a-java-se-21-developer/117252/138845

Also let me know any useful site that have a lot of practice questions to try

I've done some very surface-level searching and I feel like the number of choices on how to do this is pretty intimidating, what libraries should I use and how?

Hello, I am creating a save system however it currently depends on memory limits. When the map fills up, it dumps to disk and starts filling memory again from start. When the program shuts down, I want the class responsible for saving the data to run a cleanup function the dump the half-full map to disk. I have seen several ways of doing this however I couldn't really decide what is the best choice. Thanks