golang 100行实现微信公众平台文字乒乓球

package mainimport (        "crypto/sha1"        "encoding/xml"        "fmt"        "io"        "io/ioutil"        "log"        "net/http"        "sort"        "strings"        "time")type Request struct {        ToUserName   string        FromUserName string        CreateTime   time.Duration        MsgType      string        Content      string        MsgId        int}type Response struct {        ToUserName   string        `xml:"xml>ToUserName"`        FromUserName string        `xml:"xml>FromUserName"`        CreateTime   time.Duration `xml:"xml>CreateTime"`        MsgType      string        `xml:"xml>MsgType"`        Content      string        `xml:"xml>Content"`}func str2sha1(data string) string {        t := sha1.New()        io.WriteString(t, data)        return fmt.Sprintf("%x", t.Sum(nil))}func action(w http.ResponseWriter, r *http.Request) {        postedMsg, err := ioutil.ReadAll(r.Body)        if err != nil {                log.Fatal(err)        }        r.Body.Close()        v := Request{}        xml.Unmarshal(postedMsg, &v)        fmt.Println(v)        if v.MsgType == "text" {                v := Response{v.FromUserName, v.ToUserName, time.Second, v.MsgType, v.Content}                output, err := xml.Marshal(v)                if err != nil {                        fmt.Printf("error:%v\n", err)                }                fmt.Println(string(output))                fmt.Fprintf(w, string(output))        } else if v.MsgType == "event" {                Content := `"欢迎关注                                                                我的微信"`                v := Response{v.ToUserName, v.FromUserName, time.Second, v.MsgType, Content}                output, err := xml.Marshal(v)                if err != nil {                        fmt.Printf("error:%v\n", err)                }                fmt.Println(string(output))                fmt.Fprintf(w, string(output))        }}func checkSignature(w http.ResponseWriter, r *http.Request) {        if r.Method == "GET" {                r.ParseForm()                var token string = "gostock"                var signature string = strings.Join(r.Form["signature"], "")                var timestamp string = strings.Join(r.Form["timestamp"], "")                var nonce string = strings.Join(r.Form["nonce"], "")                var echostr string = strings.Join(r.Form["echostr"], "")                tmps := []string{token, timestamp, nonce}                sort.Strings(tmps)                tmpStr := tmps[0] + tmps[1] + tmps[2]                tmp := str2sha1(tmpStr)                if tmp == signature {                        fmt.Fprintf(w, echostr)                }        } else {                action(w, r)        }}func main() {        http.HandleFunc("/check", checkSignature)        //http.HandleFunc("/", action)        port := "80"        println("Listening on port ", port, "...")        err := http.ListenAndServe(":"+port, nil) //设置监听的端口        if err != nil {                log.Fatal("ListenAndServe: ", err)        }}