Add routes

src/main.rs

@@ -1,4 +1,5 @@
 mod config;
+mod routes;
 
 use config::Config;
 
@@ -13,7 +14,9 @@ async fn main() -> std::io::Result<()> {
         .init();
 
     actix_web::HttpServer::new(|| {
-        actix_web::App::new().wrap(actix_web::middleware::Logger::default())
+        actix_web::App::new()
+            .wrap(actix_web::middleware::Logger::default())
+            .service(routes::languages::index)
     })
     .bind(config.bind())?
     .run()

src/routes/languages.rs

@@ -0,0 +1,10 @@
+use super::Result;
+
+use actix_web::{get, HttpResponse};
+
+#[get("/languages")]
+async fn index() -> Result {
+    Ok(HttpResponse::Ok()
+        .content_type("application/json; charset=utf-8")
+        .body("{\"hello\":\"Hello, World!\"}"))
+}

src/routes/mod.rs

@@ -0,0 +1,31 @@
+pub mod languages;
+
+use std::fmt::{self, Display};
+
+use actix_web::{http::StatusCode, HttpResponse};
+
+pub type Result = std::result::Result<HttpResponse, Error>;
+
+#[derive(Debug)]
+pub enum Error {}
+
+impl Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "Error.")
+    }
+}
+
+impl actix_web::error::ResponseError for Error {
+    fn status_code(&self) -> StatusCode {
+        StatusCode::INTERNAL_SERVER_ERROR
+    }
+
+    fn error_response(&self) -> HttpResponse {
+        actix_web::HttpResponseBuilder::new(self.status_code())
+            .insert_header((
+                actix_web::http::header::CONTENT_TYPE,
+                "application/json; charset=utf-8",
+            ))
+            .body("{\"error\":\"Error!\"")
+    }
+}