go_http_err.go

package main

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

func main() {
	http.HandleFunc("/500", func(res http.ResponseWriter, req *http.Request) {
		res.WriteHeader(500)
		res.Write([]byte("NOT-OK"))
	})
	go http.ListenAndServe(":8080", nil)

	res, err := http.Get("http://127.0.0.1:8080/500")
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("res.StatusCode: %d\n", res.StatusCode)
}