This section describes the usage of the asynchronous JAX-RS API on the client for calling the RESTful web APIs.
To invoke a REST API asynchronously on the client, you use javax.ws.rs.client.AsyncInvoker. The AsyncInvoker instance is obtained from the call of the Invocation.Builder.async() method, as shown in the following code:
//Other imports are omitted for brevity
import javax.ws.rs.client.AsyncInvoker;
import javax.ws.rs.client.Client;
import javax.ws.rs.client.WebTarget;
import javax.ws.rs.core.GenericType;
import javax.ws.rs.core.Response;
String BASE_URI =
"http://localhost:8080/hr-services/webresources";
Client client = ClientBuilder.newClient();
WebTarget webTarget = client.target(BASE_URI).path("hr").path("departments");
AsyncInvoker asyncInvoker =
webTarget.request(APPLICATION_JSON).async();
Future<Response> responseFuture = asyncInvoker.get();
Response response = responseFuture.get();
List<Department> depts = response...