actix-web/guide/src/qs_7.md

HttpRequest & HttpResponse

Content encoding

Actix automatically compress/decompress payload. Following codecs are supported:

• Brotli
• Gzip
• Deflate
• Identity

If request headers contains Content-Encoding header, request payload get decompressed according to header value. Multiple codecs are not supported, i.e: Content-Encoding: br, gzip.

Response payload get compressed based on content_encoding parameter. By default ContentEncoding::Auto is used. If ContentEncoding::Auto is selected then compression depends on request's Accept-Encoding header. ContentEncoding::Identity could be used to disable compression. If other content encoding is selected the compression is enforced for this codec. For example, to enable brotli response's body compression use ContentEncoding::Br:

extern crate actix_web;
use actix_web::*;

fn index(req: HttpRequest) -> HttpResponse {
    HttpResponse::Ok()
        .content_encoding(ContentEncoding::Br)
        .body("data").unwrap()
}
# fn main() {}

JSON Response

The Json type allows you to respond with well-formed JSON data: simply return a value of type Json where T is the type of a structure to serialize into JSON. The type T must implement the Serialize trait from serde.

extern crate actix_web;
#[macro_use] extern crate serde_derive;
use actix_web::*;

#[derive(Serialize)]
struct MyObj {
    name: String,
}

fn index(req: HttpRequest) -> Result<Json<MyObj>> {
    Ok(Json(MyObj{name: req.match_info().query("name")?}))
}

fn main() {
    Application::default("/")
        .resource(r"/a/{name}", |r| r.method(Method::GET).handler(index))
        .finish();
}