Golang订单管理实现方法详解

type Order struct {
    ID        string    `json:"id"`
    UserID    string    `json:"user_id"`
    Items     []Item    `json:"items"`
    Total     float64   `json:"total"`
    CreatedAt time.Time `json:"created_at"`
}

type Item struct {
    ProductID string  `json:"product_id"`
    Name      string  `json:"name"`
    Price     float64 `json:"price"`
    Quantity  int     `json:"quantity"`
}

type OrderService struct {
    orders map[string]Order
    mu     sync.Mutex
}

func NewOrderService() *OrderService {
    return &OrderService{
        orders: make(map[string]Order),
    }
}

// CreateOrder 创建新订单
func (s *OrderService) CreateOrder(order Order) {
    s.mu.Lock()
    defer s.mu.Unlock()
    order.CreatedAt = time.Now()
    s.orders[order.ID] = order
}

// GetOrder 根据ID获取订单
func (s *OrderService) GetOrder(id string) (Order, bool) {
    s.mu.Lock()
    defer s.mu.Unlock()
    order, exists := s.orders[id]
    return order, exists
}

// UpdateOrder 更新订单（简单替换）
func (s *OrderService) UpdateOrder(order Order) bool {
    s.mu.Lock()
    defer s.mu.Unlock()
    if _, exists := s.orders[order.ID]; !exists {
        return false
    }
    s.orders[order.ID] = order
    return true
}

// DeleteOrder 删除订单
func (s *OrderService) DeleteOrder(id string) bool {
    s.mu.Lock()
    defer s.mu.Unlock()
    if _, exists := s.orders[id]; !exists {
        return false
    }
    delete(s.orders, id)
    return true
}

func main() {
    service := NewOrderService()

    http.HandleFunc("/orders", func(w http.ResponseWriter, r *http.Request) {
        switch r.Method {
        case "GET":
            // 返回所有订单（仅演示）
            w.Header().Set("Content-Type", "application/json")
            json.NewEncoder(w).Encode(service.orders)
        case "POST":
            var order Order
            json.NewDecoder(r.Body).Decode(&order)
            service.CreateOrder(order)
            w.WriteHeader(http.StatusCreated)
            json.NewEncoder(w).Encode(order)
        }
    })

    http.HandleFunc("/orders/", func(w http.ResponseWriter, r *http.Request) {
        id := strings.TrimPrefix(r.URL.Path, "/orders/")
        order, exists := service.GetOrder(id)
        if !exists {
            http.NotFound(w, r)
            return
        }
        json.NewEncoder(w).Encode(order)
    })

    http.ListenAndServe(":8080", nil)
}