【Axum】请求共享状态

环境

• Time 2022-01-19
• Rust 1.58.0
• Axum 0.4.4

概念

参考：https://docs.rs/axum/latest/axum/index.html

示例

main.rs

use axum::extract::Extension;
use axum::AddExtensionLayer;
use axum::{routing::get, Router};
use std::{net::SocketAddr, sync::Arc};

struct State {
    name: String,
}

#[tokio::main]
async fn main() {
    let shared_state = Arc::new(State {
        name: "JiangBo".to_owned(),
    });
    let app = Router::new()
        .route("/", get(home))
        .layer(AddExtensionLayer::new(shared_state));

    let addr = SocketAddr::from(([127, 0, 0, 1], 4444));
    println!("listening on {addr}");
    axum::Server::bind(&addr)
        .serve(app.into_make_service())
        .await
        .unwrap();
}

async fn home(Extension(state): Extension>) -> String {
    state.name.clone()
}

总结

通过定义一个共享的变量，在每个请求中共享状态。

附录