The biggest help that I got from my company is that they helped me identify a pet project which is small enough to make sense, but complex enough to help me learn. In general, it uploads, exposes some files, and later modifies them via an open-source library. This enables me to learn in a way that I know what I want to build and I learn what I need for the next chapter. I will share here where the guides that helped me a lot.

Accessing data with MySQL
(or how to use MySQL with Spring)

It took me some time to understand that I don’t actually need to write the queries myself but JPA will take care of it and I only have to care for the data model (this is simplification, for sure). My thinking before was that it must work in a way that I have to construct the query as any spring (like “select version from excel_file where uuid=\”” + result.uuid + “\;”).

To make this work, I had to figure out how to host a MySQL server using docker. Here, ChatGPT and some googling walked me through and now I am a happy user of that database.

Right now, my structure is very simple, it is only one tab, but it does do the job:

Handling Form Submission
(or how to create/host an HTML page in Java)

I learned here about Thymeleaf and controllers how to create a simple form, and how to connect it to a template and access it from the browser. The pet project I am working on is more backend-facing and the UI is only the backup, I did not focus too much on this, I built a generic template with error handling. It was still useful to understand how these are connected conceptually.