前往：在一个函数中接受不同的套接字调用

Question

I'm trying to get my web server to accept different socket calls in one function. My code looks like this:

Go:

func handler(w io.Writer, r *io.ReadCloser) {
    //do something
}

func main() {
    http.HandleFunc("/", handler)
    http.ListenAndServe(":3000", nil)
}

I get the error:

cannot use handler (type func(io.Writer, *io.ReadCloser)) as type func(http.ResponseWriter, *http.Request) in argument to http.HandleFunc

How do I implement this?

Answer 1

As shown in the article "Writing Web Applications", the example for HandleFunc is:

package main

import (
    "fmt"
    "net/http"
)

func handler(w http.ResponseWriter, r *http.Request) {
    fmt.Fprintf(w, "Hi there, I love %s!", r.URL.Path[1:])
}

func main() {
    http.HandleFunc("/", handler)
    http.ListenAndServe(":8080", nil)
}

You cannot replace a r *http.Request by an r *io.ReadCloser.

You would need to delegate that call in a wrapper, as suggested in this thread:

func wrappingHandler(w http.ResponseWriter, r *http.Request){
    handler(w, r.Body)
}
func main() {
    http.HandleFunc("/", wrappingHandler)
    http.ListenAndServe(":8080", nil)
}

Or simply modify your handler:

func handler(w http.ResponseWriter, r *http.Request) {
    rb := r.Body
    //do something with rb instead of r
}