Building RESTful Web Services with Java EE 8

Implementing asynchronous web service clients

In this section, we're going to take a look at the basic usage of asynchronous JAX-RS client APIs. We're using InvocationCallback instances to react to completed and failed calls. We'll also see how to do invocation-chaining of asynchronous client requests with CompletableFuture.

Let's get started and switch to code. As usual, we prepared a small template project to get started. We'll be using a JUnit test to showcase the JAX-RS client APIs. We're going to set up the JAX-RS client instance and the JAX-RS webTarget instance for the previously implemented asynchronous service API. As you might remember, in the previous section, we used Fibonacci number calculations asynchronously. We'll rewrite ...