CompletableFuture: composable asynchronous programming - Java 8 in Action: Lambdas, Streams, and Functional-Style Programming - page 321

Listing 11.14. The Discount service
11.4.2. Using the Discount service
Because the Discount service is a remote service, you again add a simulated delay of 1 second to
it, as shown in the following listing. As you did in section 11.3 , first try to reimplement the
findPrices method to fit these new requirements in the most obvious (but sadly sequential and
synchronous) way.
Listing 11.15. Simplest findPrices implementation that uses the Discount
service
The desired result is obtained by pipelining three map operations on the stream of shops:
 The first operation transforms each shop into a String that encodes the price and discount code of the
requested product for that shop.
 The second operation parses those String s, converting each of them in a Quote object.
 Finally, the third one contacts the remote Discount service that will calculate the final discounted
price and return another String containing the name of the shop with that price.