无法将闭包传递给“Hyper::service_fn”
Can't pass closure to `Hyper::service_fn`
我想用 hyper 写一个简单的微服务:
use hyper::service::{make_service_fn, service_fn};
use hyper::{Body, Request, Response, Server};
use hyper::{Method, StatusCode};
use std::{convert::Infallible, net::SocketAddr};
struct ApiServer {}
impl ApiServer {
pub async fn route(&mut self, req: Request<Body>) -> Result<Response<Body>, Infallible> {
let mut response = Response::new(Body::empty());
*response.body_mut() = req.into_body();
Ok(response)
}
}
#[tokio::main]
async fn main() {
let addr = SocketAddr::from(([127, 0, 0, 1], 3000));
let mut api = ApiServer {};
let make_svc = make_service_fn(|_conn| async {
Ok::<_, Infallible>(service_fn(|req| async { api.route(req) }))
});
let server = Server::bind(&addr).serve(make_svc);
if let Err(e) = server.await {
eprintln!("server error: {}", e);
}
}
我遇到编译器错误:
error[E0271]: type mismatch resolving `<impl std::future::Future as std::future::Future>::Output == std::result::Result<http::response::Response<_>, _>`
--> src/master/bin/main.rs:46:38
|
46 | let server = Server::bind(&addr).serve(make_svc);
| ^^^^^ expected opaque type, found enum `std::result::Result`
|
如何重写代码以使 route
函数成为 ApiServer
s 成员函数?
Rust 错误消息与您的预期相反:serve()
需要 Result
但发现了 opaque
类型。您需要等待 api.route(req)
的 return 值。修复其他编译错误,最终代码为:
use hyper::service::{make_service_fn, service_fn};
use hyper::{Body, Request, Response, Server};
use std::{convert::Infallible, net::SocketAddr};
#[derive(Clone, Copy)]
struct ApiServer {}
impl ApiServer {
pub async fn route(&mut self, req: Request<Body>) -> Result<Response<Body>, Infallible> {
let mut response = Response::new(Body::empty());
*response.body_mut() = req.into_body();
Ok(response)
}
}
#[tokio::main]
async fn main() {
let mut api = ApiServer {};
let make_svc = make_service_fn(move |_conn| async move {
Ok::<_, Infallible>(service_fn(move |req| async move { api.route(req).await }))
});
let addr = SocketAddr::from(([127, 0, 0, 1], 3000));
let server = Server::bind(&addr).serve(make_svc);
if let Err(e) = server.await {
eprintln!("server error: {}", e);
}
}
参见:
我想用 hyper 写一个简单的微服务:
use hyper::service::{make_service_fn, service_fn};
use hyper::{Body, Request, Response, Server};
use hyper::{Method, StatusCode};
use std::{convert::Infallible, net::SocketAddr};
struct ApiServer {}
impl ApiServer {
pub async fn route(&mut self, req: Request<Body>) -> Result<Response<Body>, Infallible> {
let mut response = Response::new(Body::empty());
*response.body_mut() = req.into_body();
Ok(response)
}
}
#[tokio::main]
async fn main() {
let addr = SocketAddr::from(([127, 0, 0, 1], 3000));
let mut api = ApiServer {};
let make_svc = make_service_fn(|_conn| async {
Ok::<_, Infallible>(service_fn(|req| async { api.route(req) }))
});
let server = Server::bind(&addr).serve(make_svc);
if let Err(e) = server.await {
eprintln!("server error: {}", e);
}
}
我遇到编译器错误:
error[E0271]: type mismatch resolving `<impl std::future::Future as std::future::Future>::Output == std::result::Result<http::response::Response<_>, _>`
--> src/master/bin/main.rs:46:38
|
46 | let server = Server::bind(&addr).serve(make_svc);
| ^^^^^ expected opaque type, found enum `std::result::Result`
|
如何重写代码以使 route
函数成为 ApiServer
s 成员函数?
Rust 错误消息与您的预期相反:serve()
需要 Result
但发现了 opaque
类型。您需要等待 api.route(req)
的 return 值。修复其他编译错误,最终代码为:
use hyper::service::{make_service_fn, service_fn};
use hyper::{Body, Request, Response, Server};
use std::{convert::Infallible, net::SocketAddr};
#[derive(Clone, Copy)]
struct ApiServer {}
impl ApiServer {
pub async fn route(&mut self, req: Request<Body>) -> Result<Response<Body>, Infallible> {
let mut response = Response::new(Body::empty());
*response.body_mut() = req.into_body();
Ok(response)
}
}
#[tokio::main]
async fn main() {
let mut api = ApiServer {};
let make_svc = make_service_fn(move |_conn| async move {
Ok::<_, Infallible>(service_fn(move |req| async move { api.route(req).await }))
});
let addr = SocketAddr::from(([127, 0, 0, 1], 3000));
let server = Server::bind(&addr).serve(make_svc);
if let Err(e) = server.await {
eprintln!("server error: {}", e);
}
}
参见: