Added error response example.

examples/errors.rs

@@ -0,0 +1,50 @@
+use actix::System;
+use actix_web::http::StatusCode;
+use actix_web::web::{get, resource, HttpRequest, HttpResponse};
+use actix_web::{App, HttpServer, ResponseError};
+use futures::future::err;
+use futures::Future;
+use serde::Serialize;
+use serde_json;
+use std::fmt::{Display, Formatter, Result as FmtResult};
+use std::io;
+
+#[derive(Debug, Serialize)]
+struct Error {
+    msg: String,
+    status: u16,
+}
+
+impl Display for Error {
+    fn fmt(&self, f: &mut Formatter) -> FmtResult {
+        let err_json = serde_json::to_string(self).unwrap();
+        write!(f, "{}", err_json)
+    }
+}
+
+impl ResponseError for Error {
+    fn render_response(&self) -> HttpResponse {
+        HttpResponse::build(StatusCode::from_u16(self.status).unwrap()).json2(self)
+    }
+}
+
+fn index(_: HttpRequest) -> impl Future<Item = HttpResponse, Error = Error> {
+    err(Error {
+        msg: "test".to_string(),
+        status: 400,
+    })
+}
+
+fn main() -> io::Result<()> {
+    let sys = System::new("simple_error_response");
+    let ip_address = "127.0.0.1:8000";
+
+    HttpServer::new(|| App::new().service(resource("/").route(get().to_async(index))))
+        .bind(ip_address)
+        .expect("Can not bind to port 8000")
+        .start();
+
+    println!("Running server on {}", ip_address);
+
+    sys.run()
+}