Rust 实战练习 - 12. Axum Web 简单demo

Rust Web 历程

Rust 的异步框架tokio非他莫属，而web框架一直是悬而未决，说到底还是因为没有官方成熟的方案指引，大家各玩各的，互不兼容，白白浪费精力。

这个事情一直等到半官方组织tokio推出axum有了改善。但是市场上仍然乱七八糟，具体细节可以参考：https://zhuanlan.zhihu.com/p/398232138

现在相对靠谱的发展方向参考如下图：
在这里插入图片描述

但是 tower和tower-http这2个项目比较奇葩，sample和docment严重缺少，所以建议做如下研究：

tokio
axum
tonic
sqlx

axum 简单demo

这个框架也不是特别成熟，在multipart有大坑!
注意仔细参考我的代码!

use axum::{extract::{DefaultBodyLimit, Form, Multipart, Path, Query}, http::{Method, StatusCode}, response::{Html, IntoResponse}, routing::{get, post}, Json, Router};
use serde::{Deserialize, Serialize};


#[tokio::main]
async fn main() {
    let routes = Router::new()
        .route("/", get(page_index))
        .route("/hello", get(|| async {
            println!("{:<12} - hello", "HANDLER");
            Html("hello world!")
        }))
        .route("/user", post(page_user))
        .route("/user2", get(page_user2))
        .route("/user3/:username", get(page_user3))
        .route("/form", get(form_get).post(form_post))
        // 复杂的提取，需要参考 https://docs.rs/axum/latest/axum/extract/index.html
        .route("/form2", get(form_get_file).post(form_post_file).layer(DefaultBodyLimit::disable()))
        ;

    let listener = tokio::net::TcpListener::bind("0.0.0.0:8080").await.unwrap();
    println!("Server listen on: {:?}", listener.local_addr());
    axum::serve(listener, routes).await.unwrap();

}



#[derive(Deserialize, Debug)]
struct ReqUser {
    username: String,
}

#[derive(Serialize, Debug,Deserialize)]
struct RespUser {
    id: u64,
    username: String,
}

async fn page_index() -> &'static str{
    "welcome to axum based on tokio!"
}

// e.g.: Post /user  Body: {"username": "xxxx"}
async fn page_user(
    Json(req): Json<ReqUser>,
) -> (StatusCode, Json<RespUser>) {
    println!("{:<12} - page_user - {req:?}", "HANDLER");
    let user = RespUser {
        id: 1337,
        username: req.username,
    };
    (StatusCode::OK, Json(user))
}

// e.g.: GET /user2?username=abc
async fn page_user2(
    Query(req) : Query<ReqUser>
) -> impl IntoResponse {
    println!("{:<12} - page_user2 - {req:?}", "HANDLER");
    let user = RespUser {
        id: 1338,
        username: req.username,
    };
    Html(format!("{user:?}"))
}

// e.g.: GET /user3/username
async fn page_user3(
    Path(req_name) : Path<String>
) -> impl IntoResponse {
    println!("{:<12} - page_user3 - {req_name:?}", "HANDLER");
    let user = RespUser {
        id: 1339,
        username: req_name,
    };
    Html(format!("{user:?}"))
}

async fn form_get() -> Html<&'static str> {
    Html(
        r#"
        <!doctype html>
        <html>
            <head>form test</head>
            <body>
            <h2> normal form </h2>
                <form action="/form" method="post">
                    <label for="username">
                        Enter your name:
                        <input type="text" name="username">
                    </label><br>

                    <label>
                        Enter your id:
                        <input type="text" name="id">
                    </label><br>

                    <input type="submit" value="Ok">
                </form>
            </body>
        </html>
        "#,
    )
}
async fn form_get_file() -> Html<&'static str> {
    Html(
        r#"
        <!doctype html>
        <html>
            <head>form test</head>
            <body>
            <h2> normal form </h2>
                <form action="/form2" method="post" enctype="multipart/form-data">
                    <label>
                        Enter your id:
                        <input type="text" name="id">
                    </label><br>

                    <label>
                        Upload file:
                        <input type="file" name="myfile" multiple>
                    </label><br>

                    <input type="submit" value="Upload files">
                </form>
            </body>
        </html>
        "#,
    )
}


// 支持多个提取器
async fn form_post(
    _method: Method,
    Form(user): Form<RespUser>
) -> String {
    //dbg!(&user);
    format!("{user:?}")
}

// body 部分只支持一种，不冲突的支持多种
// Form与Multipart冲突，保留multipart
async fn form_post_file(
    _method: Method,
    mut multipart: Multipart,
) -> String {
    while let Some(field) = multipart.next_field().await.unwrap() {
        let name = field.name().unwrap().to_string();
        if name == "myfile" {
            let file_name = field.file_name().unwrap().to_string();
            let content_type = field.content_type().unwrap().to_string();
            let data = field.bytes().await.unwrap();
            println!("form upload [{name}] = {file_name}, data len: {}, type: {content_type}",data.len());
        }else{
            let val = field.text().await.unwrap();
            println!("form field [{name}] = {val}");
        }
    }

    format!("{_method:?}")
}