I've been studying golang and I noticed a lot of people create servers by using the http.NewServeMux() function and I don't really understand what it does.
I read this:
In go ServeMux is an HTTP request multiplexer. It matches the URL of each incoming request against a list of registered patterns and calls the handler for the pattern that most closely matches the URL.
How is that different than just doing something like:
http.ListenAndServe(addr, nil)
http.Handle("/home", home)
http.Handle("/login", login)
What is the purpose of using multiplexing?
From net/http GoDoc and Source.
ListenAndServe starts an HTTP server with a given address and handler. The handler is usually nil, which means to use DefaultServeMux. Handle and HandleFunc add handlers to DefaultServeMux
DefaultServeMux is just a predefined http.ServeMux
var DefaultServeMux = &defaultServeMux
var defaultServeMux ServeMux
As you can see http.Handle calls DefaultServeMux internally.
func Handle(pattern string, handler Handler) { DefaultServeMux.Handle(pattern, handler) }
The purpose of http.NewServeMux() is to have your own instance of http.ServerMux for instances like when you require two http.ListenAndServe functions listening to different ports with different routes.