Golang HTTP路由处理与请求解析

http.HandleFunc("/hello", func(w http.ResponseWriter, r *http.Request) {
    fmt.Fprintf(w, "Hello, World!")
})
http.ListenAndServe(":8080", nil)

mux := http.NewServeMux()
mux.HandleFunc("/api/users", getUserList)
mux.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.Dir("assets"))))

if r.Method != "GET" {
    http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
    return
}

parts := strings.Split(r.URL.Path, "/")
if len(parts) != 3 {
    http.NotFound(w, r)
    return
}
userID := parts[2]

values := r.URL.Query()
name := values.Get("name")
age := values.Get("age")

err := r.ParseForm()
if err != nil {
    http.Error(w, "Bad request", http.StatusBadRequest)
    return
}
username := r.FormValue("username")

type User struct {
    Name string `json:"name"`
    Age  int    `json:"age"`
}

var user User
err := json.NewDecoder(r.Body).Decode(&user)
if err != nil {
    http.Error(w, "Invalid JSON", http.StatusBadRequest)
    return
}

if user.Name == "" {
    http.Error(w, "Name is required", http.StatusBadRequest)
    return
}

w.Header().Set("Content-Type", "application/json")
json.NewEncoder(w).Encode(map[string]interface{}{
    "success": true,
    "data":    user,
})