Finally finished!! If there is a lecture like this for every Java LTS version, I will definitely take it. My previous company used Java 8, but none of the functions in the lecture are being used. LOL I realized that I was really taking Java lightly, and at the end, I felt a sting when you said that I should study Java more if I didn't study generics and annotations because I didn't know them. I will study the rest of the Java series lectures diligently. Including the time to code and practice directly during the lecture, it takes exactly twice as long as the lecture time. Since you said you film at least one lecture a day, I will also aim to take at least one of Giseon's lectures and take the rest of the series and Spring. It's a shame that I only just found out that there were so many convenient functions related to functional interfaces, streams, lambdas, asynchronous improvements, and date and time.... Ha... Thank you again for preparing the lecture.