The web client API

The Vert.x core library offers a createHttpClient method from the vertx context object. Instances of io.vertx.core.http.HttpClient provides low-level methods for doing all kinds of HTTP requests with a fine-grained control over the protocol and the stream of events.

The web client API provides a simpler facade, especially for simplifying the payload data (un)marshaling. This API comes in the form of a new dependency:

<dependency>
  <groupId>io.vertx</groupId>
  <artifactId>vertx-web-client</artifactId>
  <version>${vertx.version}</version>
</dependency>

The following is a sample usage from a unit test. The test starts a HTTP server and then it does a HTTP GET request with the web client API to check that the request to the server succeeded:

@Test
public void start_http_server(TestContext context) {
  Async async = context.async();
  vertx.createHttpServer().requestHandler(req ->
    req.response().putHeader("Content-Type", "text/plain").end("Ok"))
  .listen(8080, context.asyncAssertSuccess(server -> {
    WebClient webClient = WebClient.create(vertx);
      webClient.get(8080, "localhost", "/").send(ar -> {
        if (ar.succeeded()) {
          HttpResponse<Buffer> response = ar.result();
          context.assertTrue(response.headers().contains("Content-Type"));
          context.assertEquals("text/plain", response.getHeader("Content-Type"));
          context.assertEquals("Ok", response.body().toString());
          webClient.close();
          async.complete();
        } else {
          async.resolve(Promise.failedPromise(ar.cause()));
        }
      });
    }));
}