sample code using net/http in golang

http.go

package main

import (
	"encoding/json"
	"fmt"
	"log"
	"net/http"
)

func main() {
	mux := http.NewServeMux()
	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json; charset=UTF-8")
		b := ResponseBody{
			OK:      false,
			Message: "Not Implemented",
		}
		j, e := json.Marshal(b)
		if e != nil {
			log.Fatalf("%+v", e)
		}
		fmt.Fprintln(w, string(j))
	})
	log.Fatal(http.ListenAndServe(":8080", mux))
}

type ResponseBody struct {
	OK      bool   `json:"ok"`
	Message string `json:"message"`
}