completablefuture 학습

completablefuture.java

@Slf4j
class FutureTest {

    @Test
    void init() {
        log.info("Everything is ok");
    }

    @Test
    void 동기_가져오기() {

        Shop shop = new Shop();

        log.info("모카랑 아아더하면 {}", shop.getPrice("mocha") +  shop.getPrice("americano"));

    }

    @Test
    void 비동기_가져오기() {
        Shop shop = new Shop();

        Integer total = shop.getPriceAsync("mocha").thenCombine(shop.getPriceAsync("americano"), Integer::sum).join();
        log.info("모카랑 아아더하면 {}", total);
    }

    class Shop {
        private Map<String, Integer> map = new HashMap<>();

        public Shop() {
            this.map.put("mocha", 1000);
            this.map.put("latte", 700);
            this.map.put("americano", 500);
        }

        public Integer getPrice(String name) {
            try {
                log.info("Thread 기다림");
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            return map.get(name);
        }

        public CompletableFuture<Integer> getPriceAsync(String name) {
            return CompletableFuture.supplyAsync(() -> {
                log.info("supply async");
                return getPrice(name);
            });
        }
    }