Supporting HTTP Engine Registration In RESTEasy Client and RESTEasy MicroProfile Client

By Wei Nan Li | November 03, 2021

Recently I have submitted two pull requests in resteasy and resteasy-microprofile project to allow client side HTTP engine registration:

By above two pull requests, now we can inject custom HTTP engine into client by the register() method defined by the ClientBuilder interface.

For example, we can inject a customized Vert.x HTTP engine to support HTTP/2 communitcation, and here is the code example using standard restesay-client:

Vertx vertx = Vertx.vertx();
HttpClientOptions options = new HttpClientOptions();
options.setSsl(true);
options.setProtocolVersion(HttpVersion.HTTP_2);
options.setUseAlpn(true);
Client client = ClientBuilder
        .newBuilder()
        .register(new VertxClientHttpEngine(vertx, options))
        .build();
final Response resp = client.target("https://nghttp2.org/httpbin/get").request().get();
assertEquals(200, resp.getStatus());
Assert.assertTrue(resp.readEntity(String.class).contains("nghttp2.org"));

From the above code we can see that a customized VertxClientHttpEngine instance is registered into client by calling the register() method of ClientBuilder. To do the same thing by using resteasy-microprofile-client, here is the code example:

RestClientBuilder builder = RestClientBuilder.newBuilder().baseUri(URI.create("https://nghttp2.org/"));

Vertx vertx = Vertx.vertx();
HttpClientOptions options = new HttpClientOptions();
options.setSsl(true);
options.setProtocolVersion(HttpVersion.HTTP_2);
options.setUseAlpn(true);

builder.register(new VertxClientHttpEngine(vertx, options));

NgHTTP2 client = builder.build(NgHTTP2.class);

final String resp = client.get();
assertTrue(resp.contains("nghttp2.org"));

The difference with resteasy-client is that RestClientBuilder should be used instead of ClientBuilder. In addition, the NgHTTP2 in above code is a MicroProfile Client based client proxy interface:

import org.eclipse.microprofile.rest.client.inject.RegisterRestClient;

import javax.ws.rs.GET;
import javax.ws.rs.Path;

@RegisterRestClient
public interface NgHTTP2 {
    @GET
    @Path("httpbin/get")
    String get();
}

With above interface we can make call to the URL address.

Hope this new feature is useful to you :D