Difference between http.Handle and http.HandleFunc?

Basically, the HTTP server's "mux" has a map of path -> handler interface

Interfaces are used here, I assume, to allow you to implement complex path handlers that have state.

For example the file server from the standard package is a struct that contains the root dir for file service and implements the handler interface.

That said, for simple stuff, a func is easier and more clear. So they added a special generator so you can easily pass in a func.

Take a look at: server.go

from line: 1216 (as of today)

  1216  type HandlerFunc func(ResponseWriter, *Request)
  1217  
  1218  // ServeHTTP calls f(w, r).
  1219  func (f HandlerFunc) ServeHTTP(w ResponseWriter, r *Request) {
  1220      f(w, r)
  1221  }

What they are doing is implementing the interface on a custom type (which happens to match the api of the interface) that just calls itself.


Very correct answers so I won't say much but explain it in simple terms:

Problem: I want to create an object (type) that responds to HTTP requests.

Solution: use http.Handle and the object you create should implement ServeHTTP interface from the HTTP package.

Problem: I want a function to respond to my HTTP request.

Solution: Use http.HandleFunc for that and register your function with the HTTP server.