Golang构建简单支付系统教程

type Order struct {
  ID string `json:"id"`
  Amount float64 `json:"amount"`
  Status string `json:"status"` // pending, paid, failed
  CreatedAt int64 `json:"created_at"`
}

type Payment struct {
  OrderID string `json:"order_id"`
  PaidAt int64 `json:"paid_at"`
  PaymentID string `json:"payment_id"`
}

var (
  orders = make(map[string]*Order)
  payments = make(map[string]*Payment)
)

func CreateOrder(amount float64) *Order {
  orderID := fmt.Sprintf("ord_%d", time.Now().Unix())
  order := &Order{
    ID: orderID,
    Amount: amount,
    Status: "pending",
    CreatedAt: time.Now().Unix(),
  }
  orders[orderID] = order
  return order
}

func PayOrder(orderID string) (*Payment, error) {
  order, exists := orders[orderID]
  if !exists {
    return nil, errors.New("订单不存在")
  }
  if order.Status == "paid" {
    return nil, errors.New("订单已支付")
  }
  order.Status = "paid"
  payment := &Payment{
    OrderID: orderID,
    PaymentID: fmt.Sprintf("pay_%d", time.Now().Unix()),
    PaidAt: time.Now().Unix(),
  }
  payments[payment.PaymentID] = payment
  return payment, nil
}

func main() {
  http.HandleFunc("/create", func(w http.ResponseWriter, r *http.Request) {
    amount, _ := strconv.ParseFloat(r.FormValue("amount"), 64)
    order := CreateOrder(amount)
    json.NewEncoder(w).Encode(order)
  })

  http.HandleFunc("/pay", func(w http.ResponseWriter, r *http.Request) {
    orderID := r.FormValue("order_id")
    payment, err := PayOrder(orderID)
    if err != nil {
      http.Error(w, err.Error(), http.StatusBadRequest)
      return
    }
    json.NewEncoder(w).Encode(payment)
  })

  log.Println("服务启动在 :8080")
  http.ListenAndServe(":8080", nil)
}

go func() {
  time.Sleep(500 * time.Millisecond) // 模拟网络延迟
  resp, _ := http.PostForm("https://your-merchant.com/callback",
    url.Values{"order_id": {orderID}, "status": {"success"}})
  if resp != nil {
    resp.Body.Close()
  }
}()