How to make StaticHandler download all Mime types?

Question

I have a basic verticle serving files from the data folder:

public class Server extends AbstractVerticle
{ 
  @Override
  public void start() throws Exception {
    Router router = Router.router(vertx);
    router.route().handler(BodyHandler.create());
    router.route("/static/*").handler(StaticHandler.create("data"));
    vertx.createHttpServer().requestHandler(router).listen(8080);
  }
}

The server downloads files as .docx, but renders all images or PDFs within the browser.

How can I tell my StaticHandler to download all MIME types?

Can I somehow set the Content-Disposition: attachment header globally for the whole StaticHandler? Or have some hooks where I can set it dependent on the routing context?

Answer 1

You can set several handlers on a route definition. On the /static/* route, set a handler which, when the response is ready to be sent, adds an extra header:

public class Server extends AbstractVerticle
{ 
  @Override
  public void start() throws Exception {
    Router router = Router.router(vertx);
    router.route().handler(BodyHandler.create());
    router.route("/static/*")
        .handler(rc -> {
            HttpServerResponse resp = rc.response();
            resp.headersEndHandler(v-> {
              // perhaps checks response status code before adding the header
              resp.putHeader(io.vertx.core.http.HttpHeaders.CONTENT_DISPOSITION, "attachment");
            });
            rc.next();
        })
        .handler(StaticHandler.create("data"));
    vertx.createHttpServer().requestHandler(router).listen(8080);
  }
}