Golang简单实现web服务器返回json数据

package main
import (
        "io"
        "net/http"
		"log"
		"encoding/json"
)
type Data struct{
	Name string
	Age int
}
type Ret struct{
	Code int
	Param string
	Msg string
	Data []Data
}
func HelloServer(w http.ResponseWriter, req *http.Request) {
	data := Data{Name: "why", Age: 18}

	ret := new(Ret)
	id := req.FormValue("id")
	//id := req.PostFormValue('id')

	ret.Code = 0
	ret.Param = id
	ret.Msg = "success"
	ret.Data = append(ret.Data, data)
	ret.Data = append(ret.Data, data)
	ret.Data = append(ret.Data, data)
	ret_json,_ := json.Marshal(ret)
	
	io.WriteString(w, string(ret_json))
}
func HelloServer1(w http.ResponseWriter, req *http.Request) {
	io.WriteString(w, "hello, world1!\n")
}

func main() {
		http.HandleFunc("/hello", HelloServer)
		http.HandleFunc("/hello1", HelloServer1)
        err := http.ListenAndServe(":8080", nil)
        if err != nil {
                log.Fatal("ListenAndServe: ", err)
        }
}

运行： go run web.go