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Question

I want to make middleware func to check token's validity, but at the end function I cannot get post value of it's request.

Here I put "brief" (code just to show the main idea)

func main() {
  http.Handle("/100000/000001", Verify(http.HandlerFunc(Insert)))
}

func Verify(next http.Handler) http.Handler
{
   return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
      var reqBody RequestBody
      decoder := json.NewDecoder(r.Body)
      err := decoder.Decode(&reqBody)
      Util.CheckErr(err)
      var token = RequestHeader{Token: r.Header.Get("_Token")}

      if token == dbToken {
        next.ServeHTTP(w, r)
      } else {
        Util.PutResponseMessage(w, "003", "Access danied")
      }

   })
}

func Insert(res http.ResponseWriter, req *http.Request) {
  var requestBody InsertRequestBody
    decoder := json.NewDecoder(req.Body)
    err := decoder.Decode(&requestBody)
    if err != nil {
        panic(err)
    }

    defer req.Body.Close()

    log.Println(requestBody.Username)
}

I get error like this :

http: panic serving [::1]:51269: EOF
goroutine 6 [running]:
net/http.(*conn).serve.func1(0xc0420348c0)
    C:/Go/src/net/http/server.go:1721 +0xd7
panic(0x6884e0, 0xc042008110)

But, If I directly return next.ServeHttp(r, w)

like this :

func Verify(next http.Handler) http.Handler
{
      next.ServeHTTP(w, r)
}

Then decoding process in Insert func working perfectly.

Why is it? Any answer will highly appreciated. Thankyou