This should be a relatively common problem. When I deal with the front-end and back-end, I need to determine whether there is a session to determine whether the user is logged in.

But the method I saw through the documentation is that I can only introduce a judgment once on each page, and then perform other operations. However, there must be a simpler way to deal with this matter. I really can’t figure it out myself. Please ask someone. help!

The main thing is how to set it up once, and then let all pages in the specified directory determine whether to log in, so as to facilitate the next operation