我已经不再使用 actix-web
3.x.x 到 4.x.x。之前运行良好的代码现在抛出此错误:
the trait bound `fn(actix_web::web::Query<TweetParams>, actix_web::web::Data<Pool<Postgres>>) -> impl std::future::Future {tweets4}: Handler<_, _>` is not satisfied
--> src/routes/all_routes.rs:74:14
|
74 | pub async fn tweets4(
| ^^^^^^^ the trait `Handler<_, _>` is not implemented for `fn(actix_web::web::Query<TweetParams>, actix_web::web::Data<Pool<Postgres>>) -> impl std::future::Future {tweets4}`
经过一番谷歌搜索后,似乎 there is indeed a Handler
trait在 actix
生态系统(但是,我认为不是 actix-web)。我不知道我需要在哪里实现这个特征。错误消息似乎表明它在函数本身中缺失,但我的理解是您只能在
structs
上实现特征。和 enums
,不是函数?这是处理程序代码:
#[get("/tweets4")]
pub async fn tweets4(
form: web::Query<TweetParams>,
pool: web::Data<PgPool>,
) -> Result<HttpResponse, HttpResponse> {
let fake_json_data = r#"
{ "name": "hi" }
"#;
let v: Value = serde_json::from_str(fake_json_data)
.map_err(|_| HttpResponse::InternalServerError().finish())?;
sqlx::query!(
r#"
INSERT INTO users
(id, created_at, twitter_user_id, twitter_name, twitter_handle, profile_image, profile_url, entire_user)
VALUES ($1, $2, $3, $4, $5, $6, $7, $8)
"#,
Uuid::new_v4(),
Utc::now(),
"3",
"4",
"5",
"6",
"7",
v,
)
.execute(pool.as_ref())
.await
.map_err(|e| {
println!("error is {}", e);
HttpResponse::InternalServerError().finish()
})?;
Ok(HttpResponse::Ok().finish())
}
我怎么了?如果有帮助,整个项目在 github here .
最佳答案
经过充分的反复试验,我发现:
HttpResponse
错误类型,我不得不用我自己的替换:#[derive(Debug)]
pub struct MyError(String); // <-- needs debug and display
impl std::fmt::Display for MyError {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, "A validation error occured on the input.")
}
}
impl ResponseError for MyError {} // <-- key
#[get("/tweets4")]
pub async fn tweets4(
form: web::Query<TweetParams>,
pool: web::Data<PgPool>,
) -> Result<HttpResponse, MyError> {
let fake_json_data = r#"
{ "name": "hi" }
"#;
let v: Value = serde_json::from_str(fake_json_data).map_err(|e| {
println!("error is {}", e);
MyError(String::from("oh no")) // <-- here
})?;
sqlx::query!(
//query
)
.execute(pool.as_ref())
.await
.map_err(|e| {
println!("error is {}", e);
MyError(String::from("oh no")) // <-- and here
})?;
Ok(HttpResponse::Ok().finish())
}
希望对 future 的人有所帮助!
关于Rust actix-web : the trait `Handler<_, _>` is not implemented,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/67811502/