routes.go

package main

import (
	"fmt"
	"io"
	"log"
	"net/http"
	"strings"
)

type Response struct {
	http.ResponseWriter
}

func (r *Response) Text(code int, body string) {
	r.Header().Set("Content-Type", "text/plain")
	r.WriteHeader(code)

	io.WriteString(r, fmt.Sprintf("%s\n", body))
}

func main() {
	handler := http.NewServeMux()
	handler.HandleFunc("/hello/", func(w http.ResponseWriter, r *http.Request) {
		name := strings.Replace(r.URL.Path, "/hello/", "", 1)

		resp := Response{w}
		resp.Text(http.StatusOK, fmt.Sprintf("hello %s", name))
	})
	handler.HandleFunc("/hello", func(w http.ResponseWriter, r *http.Request) {
		io.WriteString(w, "hello stranger")
	})
	log.Fatal(http.ListenAndServe(":8080", handler))
}