[](https://crates.io/crates/spring-web)
[](https://docs.rs/spring-web)
[Axum](https://github.com/tokio-rs/axum)是rust社区最优秀的Web框架之一，它是由tokio官方维护的一个基于[hyper](https://github.com/hyperium/hyper)的子项目。Axum提供了web路由，声明式的HTTP请求解析，HTTP响应的序列化等功能，而且能够与[tower](https://github.com/tower-rs)生态中的中间件结合。
## 依赖
```toml
spring-web = { version = "0.1.1" }
```
## 配置项
```toml
[web]
binding = "172.20.10.4" # 要绑定的网卡IP地址，默认127.0.0.1
port = 8000 # 要绑定的端口号，默认8080
connect_info = false # 是否使用客户端连接信息
# web中间件配置
[web.middlewares]
compression = { enable = true } # 开启压缩中间件
logger = { enable = true } # 开启日志中间件
catch_panic = { enable = true } # 捕获handler产生的panic
limit_payload = { enable = true, body_limit = "5MB" } # 限制请求体大小
timeout_request = { enable = true, timeout = 60000 } # 请求超时时间60s
# 跨域配置
cors = { enable = true, allow_origins = [
"*.github.io",
], allow_headers = [
"Authentication",
], allow_methods = [
"GET",
"POST",
], max_age = 60 }
# 静态资源配置
static = { enable = true, uri = "/static", path = "static", precompressed = true, fallback = "index.html" }
```
## API接口
App实现了[WebConfigurator](https://docs.rs/spring-web/latest/spring_web/trait.WebConfigurator.html)特征，可以通过该特征指定路由配置：
```no_run, rust, linenos, hl_lines=6 10-18
#[tokio::main]
async fn main() {
App::new()
.add_plugin(SqlxPlugin)
.add_plugin(WebPlugin)
.add_router(router())
.run()
.await
}
fn router() -> Router {
Router::new().typed_route(hello_word)
}
#[get("/")]
async fn hello_word() -> impl IntoResponse {
"hello word"
}
```
你也可以使用`auto_config`宏来实现自动配置，这个过程宏会自动将被过程宏标记的路由注册进app中：
```diff
+#[auto_config(WebConfigurator)]
#[tokio::main]
async fn main() {
App::new()
.add_plugin(SqlxPlugin)
.add_plugin(WebPlugin)
- .add_router(router())
.run()
.await
}
```
## 属性宏
上面例子中的[`get`](https://docs.rs/spring-macros/latest/spring_macros/attr.get.html)是一个属性宏，`spring-web`提供了八个标准HTTP METHOD的过程宏：`get`、`post`、`patch`、`put`、`delete`、`head`、`trace`、`options`。
也可以使用[`route`](https://docs.rs/spring-macros/latest/spring_macros/attr.route.html)宏同时绑定多个method：
```rust
use spring_web::route;
use spring_web::axum::response::IntoResponse;
#[route("/test", method = "GET", method = "HEAD")]
async fn example() -> impl IntoResponse {
"hello world"
}
```
除此之外，spring还支持一个handler绑定多个路由，这需要用到[`routes`](https://docs.rs/spring-macros/latest/spring_macros/attr.routes.html)属性宏：
```rust
use spring_web::{routes, get, delete};
use spring_web::axum::response::IntoResponse;
#[routes]
#[get("/test")]
#[get("/test2")]
#[delete("/test")]
async fn example() -> impl IntoResponse {
"hello world"
}
```
## 提取插件注册的Component
上面的例子中`SqlxPlugin`插件为我们自动注册了一个Sqlx连接池组件，我们可以使用`Component`从State中提取这个连接池，[`Component`](https://docs.rs/spring-web/latest/spring_web/extractor/struct.Component.html)是一个axum的[extractor](https://docs.rs/axum/latest/axum/extract/index.html)。
```rust
#[get("/version")]
async fn mysql_version(Component(pool): Component<ConnectPool>) -> Result<String> {
let version = sqlx::query("select version() as version")
.fetch_one(&pool)
.await
.context("sqlx query failed")?
.get("version");
Ok(version)
}
```
axum也提供了其他的[extractor](https://docs.rs/axum/latest/axum/extract/index.html)，这些都被reexport到了[`spring_web::extractor`](https://docs.rs/spring-web/latest/spring_web/extractor/index.html)下。
## 读取配置
你可以用[`Config`](https://docs.rs/spring-web/latest/spring_web/extractor/struct.Config.html)抽取toml中的配置。
```rust
#[derive(Debug, Configurable, Deserialize)]
#[config_prefix = "custom"]
struct CustomConfig {
a: u32,
b: bool,
}
#[get("/config")]
async fn use_toml_config(Config(conf): Config<CustomConfig>) -> impl IntoResponse {
format!("a={}, b={}", conf.a, conf.b)
}
```
在你的配置文件中添加相应配置：
```toml
[custom]
a = 1
b = true
```
完整代码参考[`web-example`](https://github.com/spring-rs/spring-rs/tree/master/examples/web-example)
## 在Middleware中使用Component抽取注册的组件
你也可以在[middleware中使用Extractor](https://docs.rs/axum/latest/axum/middleware/fn.from_fn.html)，注意需要遵循axum的规则。
```rust
use spring_web::{axum::{response::Response, middleware::Next}, extractor::{Request, Component}};
use spring_sqlx::ConnectPool;
async fn problem_middleware(Component(db): Component<ConnectPool>, request: Request, next: Next) -> Response {
// do something
let response = next.run(request).await;
response
}
```
完整代码参考[`web-middleware-example`](https://github.com/spring-rs/spring-rs/tree/master/examples/web-middleware-example)