pub struct Json<T>(pub T);
Available on crate feature
json
only.Expand description
JSON Extractor / Response.
When used as an extractor, it can deserialize request bodies into some type that
implements serde::Deserialize
. The request will be rejected (and a JsonRejection
will
be returned) if:
- The request doesn’t have a
Content-Type: application/json
(or similar) header. - The body doesn’t contain syntactically valid JSON.
- The body contains syntactically valid JSON but it couldn’t be deserialized into the target type.
- Buffering the request body fails.
Since parsing JSON requires consuming the request body, the Json
extractor must be
last if there are multiple extractors in a handler.
See “the order of extractors”
See JsonRejection
for more details.
Extractor example
use axum::{
extract,
routing::post,
Router,
};
use serde::Deserialize;
#[derive(Deserialize)]
struct CreateUser {
email: String,
password: String,
}
async fn create_user(extract::Json(payload): extract::Json<CreateUser>) {
// payload is a `CreateUser`
}
let app = Router::new().route("/users", post(create_user));
When used as a response, it can serialize any type that implements serde::Serialize
to
JSON
, and will automatically set Content-Type: application/json
header.
Response example
use axum::{
extract::Path,
routing::get,
Router,
Json,
};
use serde::Serialize;
use uuid::Uuid;
#[derive(Serialize)]
struct User {
id: Uuid,
username: String,
}
async fn get_user(Path(user_id) : Path<Uuid>) -> Json<User> {
let user = find_user(user_id).await;
Json(user)
}
async fn find_user(user_id: Uuid) -> User {
// ...
}
let app = Router::new().route("/users/:id", get(get_user));
Tuple Fields
0: T
Trait Implementations
sourceimpl<T, S, B> FromRequest<S, B, ViaRequest> for Json<T>where
T: DeserializeOwned,
B: HttpBody + Send + 'static,
B::Data: Send,
B::Error: Into<BoxError>,
S: Send + Sync,
impl<T, S, B> FromRequest<S, B, ViaRequest> for Json<T>where
T: DeserializeOwned,
B: HttpBody + Send + 'static,
B::Data: Send,
B::Error: Into<BoxError>,
S: Send + Sync,
type Rejection = JsonRejection
type Rejection = JsonRejection
If the extractor fails it’ll use this “rejection” type. A rejection is
a kind of error that can be converted into a response. Read more
sourceimpl<T> IntoResponse for Json<T>where
T: Serialize,
impl<T> IntoResponse for Json<T>where
T: Serialize,
sourcefn into_response(self) -> Response
fn into_response(self) -> Response
Create a response.
impl<T: Copy> Copy for Json<T>
Auto Trait Implementations
impl<T> RefUnwindSafe for Json<T>where
T: RefUnwindSafe,
impl<T> Send for Json<T>where
T: Send,
impl<T> Sync for Json<T>where
T: Sync,
impl<T> Unpin for Json<T>where
T: Unpin,
impl<T> UnwindSafe for Json<T>where
T: UnwindSafe,
Blanket Implementations
sourceimpl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more