Implementing @Async services

It's not only controllers that can be non-blocking in Spring 5; the service layer can too. Just like its lower versions, Spring 5 also supports asynchronous services to implement concurrent service transactions in the background. This recipe will highlight Callable<T> and @Async Spring native services.

Getting started

Open the current Maven project ch08 and implement some methods that run asynchronously.

How to do it...

Spring 5 offers asynchronous service layer that can be called by any asynchronous controllers. Let us build these service layer using the following steps:

1. Before we start this recipe, the use of @Async requires a thorough and appropriate configuration of any TaskExecutor type in SpringAsynchConfig including some proxy-related configurations on @EnableAsync annotation.
2. Create a package org.packt.web.reactor.service and add EmployeeService with some template methods:

public interface EmployeeService { 
   public CompletableFuture<List<Employee...