It was really good that you explained Java grammar (ex. collections, constructors, etc.) frequently used in Spring. It was really good that someone who is in the field explained it. And the best part was that it was free, so I could listen without any burden. Personally, I think I would listen without any regrets even if it was 50,000 won. Since I lack basic knowledge, I wrote down the class content in Notion and studied, and I plan to watch it several times. I came across this lecture because I lack basic knowledge of Java, but if you find this lecture difficult, it would be good to buy Everybody's Java from a bookstore and listen to it. I listened to it while watching it, and it seems good because it covers even the very basic parts. I'm looking forward to the next lecture~ The last network programming and chat program creation are more fun than I thought.