Asynchronous method in JAX-RS

AsyncResource.java

@Path("async")
@Stateless
public class AsyncResource {
    
    @Resource
    ManagedExecutorService mes;

    @GET
    public void async(@Suspended AsyncResponse ar) {
        
        String initialThread = Thread.currentThread().getName();
        System.out.println("Thread: "+ initialThread + " in action...");
        
        mes.execute(new Runnable() {
                @Override
                public void run() {
                    try {
                        String processingThread = Thread.currentThread().getName();
                        System.out.println("Processing thread: " + processingThread);

                        Thread.sleep(5000);
                        String respBody = "Process initated in " + initialThread + " and finished in " + processingThread;
                        ar.resume(Response.ok(respBody).build());                    
                        
                    } catch (InterruptedException ex) {
                        Logger.getLogger(AsyncResource.class.getName()).log(Level.SEVERE, null, ex);
                    }
                }
            });
       
        System.out.println(initialThread + " freed ...");
    }
}