I have the source code of personal diary web project here, and there is no paper, but I suggest writing it myself, otherwise I can't copy it. The project is mainly realized by javaweb technology, and the database is mysql. If a framework is used, it can be servlet native or springboot.

I was talking about the server. If you use the app, you can use Android studio directly. If it is not native, you can try to set up an h5 webpage.