如何同时使用axum::extract::Query和axum::extract::State ? &

Question

我正在构建一个需要注入状态的处理程序，并且还需要提取查询参数。

我开始只提取状态，这是有效的。它的代码看起来像这样:

#[derive(ValueEnum, Clone, Debug, serde::Deserialze, serde::Serialize)]
pub enum MyParams {
Normal,
Verbose,
}
#[derive(Debug)]
pub struct MyState {
port: u16,
}

pub async fn serve(self) {
let port = self.port;
let app = Router::new()
.route("/path", axum::routing::get(path))
.with_state(Arc::new(self));
let addr = SocketAddr::from(([127, 0, 0, 1], port));
axum::Server::bind(&addr)
.serve(app.into_make_service())
.await
.unwrap();
}
async fn path(State(middle_ware): State<Arc<MyState>>) -> impl IntoResponse {
let result = middle_ware.process().await;
(StatusCode::OK, Json(result))
}

现在我想提取查询参数，所以我更新代码如下:

async fn path(State(middle_ware): State<Arc<MyState>>, params: Query<MyParams>) -> impl IntoResponse {
println!("{:?}", params);
let result = middle_ware.process().await;
(StatusCode::OK, Json(result))
}

但是编译失败，错误是

|
24  |             .route("/path", axum::routing::get(path))
|                                  ------------------ ^^^^^^^^^ the trait `Handler<_, _, _>` is not implemented for fn item `fn(State<Arc<MyState>>, Query<MyParams>) -> impl futures::Future<Output = impl IntoResponse> {path}`
|                                  |
|                                  required by a bound introduced by this call

有什么想法可以做，能够使用axum::extract::Query和axum::extract::State ?

Answer 1

文档提供了以下示例:

https://docs.rs/axum/latest/axum/extract/index.html applying-multiple-extractors

PS:不要忘记注意提取器的顺序。

use axum::{
extract::{Path, Query},
routing::get,
Router,
};
use uuid::Uuid;
use serde::Deserialize;
let app = Router::new().route("/users/:id/things", get(get_user_things));
#[derive(Deserialize)]
struct Pagination {
page: usize,
per_page: usize,
}
impl Default for Pagination {
fn default() -> Self {
Self { page: 1, per_page: 30 }
}
}
async fn get_user_things(
Path(user_id): Path<Uuid>,
pagination: Option<Query<Pagination>>,
) {
let Query(pagination) = pagination.unwrap_or_default();
// ...
}