英文:
Clearing out Previous Request RESTFul with Go(Golang)?
问题
我已经通过golang创建了一个RESTful API。问题是，当我发送一个/product请求时，我会得到一个json格式的结果，当我重复发送这个请求时，结果会追加到之前的结果中。我想要清除REST数据缓冲区，每当我发送一个请求时，API都会给我发送新鲜的数据，而不是之前的数据。我应该怎么做？
路由处理程序：
func main() {
router := mux.NewRouter()
router.HandleFunc("/product", GetProductInfo).Methods("GET")
log.Printf("Listenning on Port %s ...\n", PORT)
log.Fatal(http.ListenAndServe(PORT, router))
}
请求处理程序：
type ProductOut struct {
ID int `json:"id,omitempty"`
Title string `json:"title,omitempty"`
Description string `json:"description,omitempty"`
Price string `json:"price,omitempty"`
Location string `json:"location,omitempty"`
Created_at string `json:"created_at,omitempty"`
Images []string `json:"images,omitempty"`
}
var product_out []ProductOut
func GetProductInfo(w http.ResponseWriter, r *http.Request) {
db_select_products := db.SelectProducts() // 从数据库获取数据
var out ProductOut
for _, ele := range db_select_products {
out.ID = contentGetFieldInteger(ele, "out_id") // 从结构字段中获取整数的方法
out.Title = contentGetFieldString(ele, "out_title") // 从结构字段中获取字符串的方法
out.Description = contentGetFieldString(ele, "out_description")
out.Price = contentGetFieldString(ele, "out_price")
out.Location = contentGetFieldString(ele, "out_location")
out.Created_at = contentGetFieldString(ele, "out_created_at")
db_select_image := db.SelectImages(out.ID) // 从数据库获取另一组数据
for _, imele := range db_select_image {
out.Images = append(out.Images, imageGetFieldString(imele, "out_path"))
fmt.Println(out.Images)
}
product_out = append(product_out, out)
out.Images = nil
}
json.NewEncoder(w).Encode(product_out)
}
英文:
I've created a RESTFul API via golang.
The Issue is that when I send a /product request I will be given the result in json and when I repeat this request the result will append prevoius.
I want to clear the REST data buffer and whenever I send a request, API send me fresh data, not with prevoius. What should I do?
Route Handler
func main() {
router := mux.NewRouter()
router.HandleFunc("/product", GetProductInfo).Methods("GET")
log.Printf("Listenning on Port %s ...\n", PORT)
log.Fatal(http.ListenAndServe(PORT, router))
}
Request Handler
type ProductOut struct {
ID int `json:"id,omitempty"`
Title string `json:"title,omitempty"`
Description string `json:"description,omitempty"`
Price string `json:"price,omitempty"`
Location string `json:"location,omitempty"`
Created_at string `json:"created_at,omitempty"`
Images []string `json:"images,omitempty"`
}
var product_out []ProductOut
func GetProductInfo(w http.ResponseWriter, r *http.Request) {
db_select_products := db.SelectProducts() // Gets data from database
var out ProductOut
for _, ele := range db_select_products {
out.ID = contentGetFieldInteger(ele, "out_id") // A method for getting integer from struct field
out.Title = contentGetFieldString(ele, "out_title") // A method for getting string from struct field
out.Description = contentGetFieldString(ele, "out_description")
out.Price = contentGetFieldString(ele, "out_price")
out.Location = contentGetFieldString(ele, "out_location")
out.Created_at = contentGetFieldString(ele, "out_created_at")
db_select_image := db.SelectImages(out.ID) // Gets another data from database
for _, imele := range db_select_image {
out.Images = append(out.Images, imageGetFieldString(imele, "out_path"))
fmt.Println(out.Images)
}
product_out = append(product_out, out)
out.Images = nil
}
json.NewEncoder(w).Encode(product_out)
}
答案1
得分: 3
你可以在你的包中将其声明为全局变量：
var product_out []ProductOut
这样，切片只会被创建一次，并在请求之间共享。
如果你想为每个请求声明一个新的切片，你应该将那行代码移到你的 GetProductInfo 函数内部。
英文:
You are declaring this as a global variable in your package:
var product_out []ProductOut
That way, the slice is just created once, and you are sharing it between requests.
If you want to declare a new slice for each request, you should move that line inside your GetProductInfo function.
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