Creating http handler - go

Question

I have main.go and I want changing to better structure(similarly main2.go ) due to if the proyect would grow up, would not be easy interpret for new developers the code.
My idea is create a folder called handle and put in it the file handle.go with all the handles methods, the trouble that I find is that I do not know how to set up http.HandleFunc("/R1", HandlerOne) and http.HandleFunc("/R2", HandlerTwo) in handler.go and call it from main2.go.
main.go
package main
import (
"fmt"
"net/http"
)
func HandlerOne(w http.ResponseWriter, req *http.Request) {
fmt.Println("message one")
}
func HandlerTwo(w http.ResponseWriter, req *http.Request) {
fmt.Println("message two")
}
func main() {
http.HandleFunc("/R1", HandlerOne)
http.HandleFunc("/R2", HandlerTwo)
err := http.ListenAndServe(":9998", nil)
if err != nil {
fmt.Printf("Server failed: ", err.Error())
}
}
main2.go
package main
import (
"fmt"
"net/http"
)
func main() {
// Call handle.go
err := http.ListenAndServe(":9998", nil)
if err != nil {
fmt.Printf("Server failed: ", err.Error())
}
}
handle.go
package handle
import (
"fmt"
"net/http"
)
func HandlerOne(w http.ResponseWriter, req *http.Request) {
fmt.Println("message one")
}
func HandlerTwo(w http.ResponseWriter, req *http.Request) {
fmt.Println("message two")
}
Note:
Thanks #kluyg for your answer. I going to add that i want that seems I do not explain very well:
That I want is create a function in
handle.go where can I can put all the mapping of the handles. i.e some like that
func SetUpMapping(...){
http.HandleFunc("/R1", HandlerOne)
http.HandleFunc("/R2", HandlerTwo)
..... //Others mapping
http.HandleFunc("/RN", HandlerN)
}
where ... should be one refence to http, but this is one package, and in the main something like code 3
code 3
main2.go
package main
import (
"fmt"
"net/http"
"handlers/handle"
)
func main() {
// Call handle.go
handle.SetUpMapping(...) // i dont know what parameter put here
err := http.ListenAndServe(":9998", nil)
if err != nil {
fmt.Printf("Server failed: ", err.Error())
}
}

Answer 1

I took your code and put main2.go into $GOPATH/handlers folder and handle.go in $GOPATH/handlers/handle folder. Then I changed main2.go to be
package main
import (
"fmt"
"net/http"
"handlers/handle"
)
func main() {
// Call handle.go
http.HandleFunc("/R1", handle.HandlerOne)
http.HandleFunc("/R2", handle.HandlerTwo)
err := http.ListenAndServe(":9998", nil)
if err != nil {
fmt.Printf("Server failed: ", err.Error())
}
}
It compiles and works fine. I believe this is what you asked for.
UPDATE
OK, you can add this to your handle.go
func SetUpMapping() {
http.HandleFunc("/R1", HandlerOne)
http.HandleFunc("/R2", HandlerTwo)
..... //Others mapping
http.HandleFunc("/RN", HandlerN)
}
then in main2.go
package main
import (
"fmt"
"net/http"
"handlers/handle"
)
func main() {
// Call handle.go
handle.SetUpMapping() // you don't need any parameters here
err := http.ListenAndServe(":9998", nil)
if err != nil {
fmt.Printf("Server failed: ", err.Error())
}
}