Catching Panics in Requests

The CatchPanic middleware is used to capture crashes that occur during request processing. For specific API details, please refer to the documentation.

Note: To use CatchPanic, enable the catch-panic feature in Cargo.toml:
salvo = { version = "xxx", features = ["catch-panic"] }

Middleware Overview

CatchPanic is a middleware designed to catch panics in handlers. When a panic occurs during request processing, it captures the panic and writes a 500 Internal Server Error response instead of crashing the entire server.

Important: This middleware should be the first one in the chain to ensure it captures panics from other middlewares or handlers.

Basic Usage

use salvo_core::prelude::*;  
use salvo_extra::catch_panic::CatchPanic;  

#[handler]  
async fn hello() {  
    panic!("panic error!");  
}  

#[tokio::main]  
async fn main() {  
    let router = Router::new().hoop(CatchPanic::new()).get(hello);  
    let acceptor = TcpListener::new("0.0.0.0:5800").bind().await;  
    Server::new(acceptor).serve(router).await;  
}

Comparison with Other Frameworks

Axum

Similar to Axum's catch_panic middleware from Tower:

use axum::{  
    Router,  
    routing::get,  
    http::StatusCode,  
};  
use tower::ServiceBuilder;  
use tower_http::catch_panic::CatchPanicLayer;  

async fn panic_handler() -> &'static str {  
    panic!("panic error!");  
}  

#[tokio::main]  
async fn main() {  
    let app = Router::new()  
        .route("/", get(panic_handler))  
        .layer(  
            ServiceBuilder::new()  
                .layer(CatchPanicLayer::new())  
        );  

    axum::Server::bind(&"0.0.0.0:3000".parse().unwrap())  
        .serve(app.into_make_service())  
        .await  
        .unwrap();  
}

Gin (Go)

In Go's Gin framework, the equivalent is the Recovery middleware:

package main  

import (  
    "github.com/gin-gonic/gin"  
)  

func main() {  
    r := gin.Default() // Includes Recovery middleware by default  

    r.GET("/", func(c *gin.Context) {  
        panic("panic error!")  
    })  

    r.Run(":8080")  
}

Example Code

import { Tab, Tabs } from 'rspress/theme';  
import CatchPanicCode from '../../../../codes_md/catch-panic/src/main.mdx';  
import CatchPanicCargoCode from '../../../../codes_md/catch-panic/Cargo.mdx';  

<Tabs>  
  <Tab label="main.rs">  
    <CatchPanicCode/>  
  </Tab>  
  <Tab label="Cargo.toml">  
    <CatchPanicCargoCode/>  
  </Tab>  
</Tabs>

On this page

#Catching Panics in Requests

#Middleware Overview

#Basic Usage

#Comparison with Other Frameworks

#Axum

#Gin (Go)