Solve the pitfalls encountered when golang reads http body

func main(){
 url:="http://127.0.0.1:8335/api/v2/submit"
 myReq:= struct {
 ProductId  int  `json:"product_id"`
 Mobile   string `json:"mobile"`
 Content  string  `json:"content"`
 Grade  float64 `form:"grade" json:"grade"`
 Image  string `form:"image" json:"image"`
  Longitude  float64    `json:"longitude"`
 Latitude  float64   `json:"latitude"`
 }{
 ProductId:219,
 Mobile:"15911111111",
 Content: "This software logo is so ugly",
 Image: ";",
 Longitude: 106.3037109375,
 Latitude: 38.5137882595,
 Grade:9.9,
 }
 reqByte,err:=(myReq)
 req, err := ("POST", url, (reqByte))
 if err != nil {
 return
 }
 //Set request header ("Content-Type", "application/json")
 cli := {
 Timeout: 45 * ,
 }
 resp, err := (req)
 if err != nil {
 return
 }
 out, err := ()
 if err != nil {
 return
 }
 (string(out))
}

func SubmitV2(c *) {
 resp := &{}
 obj:=make(map[string]interface{})
 var buf []byte
 var err error
 buf, err =(c. )
 if err!=nil {
 return
 }
 err=(buf,&obj)
 if err!=nil {
 return
 }
 ("product_id:",(obj["product_id"]))
 ("image:",(obj["image"]))
 (obj)
 productId:=obj["product_id"].(float64)
 //Note that it will cause an error when asserting it as an int type here  = ((buf))
 if !checkProduct(int(productId)){
  = -1
  = "xxxxxx"
 (, resp)
 return
 }
 url :=  + "/api/v1/submit"
 err = http_utils.PostAndUnmarshal(url, , nil, resp)
 if err != nil {
 (err).Errorln("Submit: error")
  = -1
  = "Submit"
 }
 (, resp)
}

package main
import (
 "fmt"
 "net/http"
)
func headerBody(rw , r *) {
 // Get the content length of the request message len := 
 // Create a new byte slice, the length is the same as the content of the request message body := make([]byte, len)
 // Read the request body of r and read the specific content into the body (body)
 // Write the content of the byte slice into the corresponding message (rw, body)
}
func main() {
 server := {
 Addr: "127.0.0.1:http",
 }
 ("/", headerBody)
 ()
}