(The basic part of Java is mainly explained in the complete set of Java basics. Most of the code inside is the code that I have practiced and written during the lecture. These codes can run normally. There are also notes collected by myself. In the process of collection, because there are too many codes written before, it is not convenient to put them all on top, so only a few more friendly codes that I like are added. I think it will be very helpful for beginners. The process of writing this document has taken me nearly a month. I hope you respect knowledge and labor achievements. I will share these contents with you all for free, If there is any incorrect information found in the process of reading, I hope you can tell me so that I can correct it in time and not let beginners enter the boundless road.)