Golang实现简易Todo应用教程

type Todo struct {
    ID     int    `json:"id"`
    Title  string `json:"title"`
    Done   bool   `json:"done"`
}

var todos []Todo
var nextID = 1

func getTodos(w http.ResponseWriter, r *http.Request) {
    w.Header().Set("Content-Type", "application/json")
    json.NewEncoder(w).Encode(todos)
}

func createTodo(w http.ResponseWriter, r *http.Request) {
    var newTodo Todo
    if err := json.NewDecoder(r.Body).Decode(&newTodo); err != nil {
        http.Error(w, "Invalid JSON", http.StatusBadRequest)
        return
    }
    newTodo.ID = nextID
    nextID++
    todos = append(todos, newTodo)
    w.Header().Set("Content-Type", "application/json")
    w.WriteHeader(http.StatusCreated)
    json.NewEncoder(w).Encode(newTodo)
}

func updateTodo(w http.ResponseWriter, r *http.Request) {
    idStr := strings.TrimPrefix(r.URL.Path, "/todos/")
    id, _ := strconv.Atoi(idStr)

    for i := range todos {
        if todos[i].ID == id {
            json.NewDecoder(r.Body).Decode(&todos[i])
            json.NewEncoder(w).Encode(todos[i])
            return
        }
    }
    http.Error(w, "Todo not found", http.StatusNotFound)
}

func deleteTodo(w http.ResponseWriter, r *http.Request) {
    idStr := strings.TrimPrefix(r.URL.Path, "/todos/")
    id, _ := strconv.Atoi(idStr)

    for i, todo := range todos {
        if todo.ID == id {
            todos = append(todos[:i], todos[i+1:]...)
            w.WriteHeader(http.StatusNoContent)
            return
        }
    }
    http.Error(w, "Todo not found", http.StatusNotFound)
}

func main() {
    http.HandleFunc("GET /todos", getTodos)
    http.HandleFunc("POST /todos", createTodo)
    http.HandleFunc("PUT /todos/{id}", updateTodo)
    http.HandleFunc("DELETE /todos/{id}", deleteTodo)

    fmt.Println("Server starting on :8080...")
    http.ListenAndServe(":8080", nil)
}