golang web服务器处理前端HTTP请求跨域的方法

直接上代码：）

package main

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

type httpServer struct {
}

func (s *httpServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
// Stop here if its Preflighted OPTIONS request
if origin := r.Header.Get("Origin"); origin != "" {
w.Header().Set("Access-Control-Allow-Origin", "*")
w.Header().Set("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, DELETE")
w.Header().Set("Access-Control-Allow-Headers",
"Action, Module")   //有使用自定义头 需要这个,Action, Module是例子
}

if r.Method == "OPTIONS" {
return
}

w.Write([]byte("hello"))
}

func main() {
addr := flag.String("http-address", "", "")
flag.Parse()

var h httpServer

httpListener, err := net.Listen("tcp", *addr)
server := http.Server{
Handler: &h,
}
server.Serve(httpListener)

fmt.Println("finish ", err)
}