Future in WebApp (Java)

Transcript

1. Future in WebApp Kengo TODA

2. Agenda • What is Future • What is CompletableFuture •

   Common usage in WebApp

3. What is Future? • Proxy interface to get result of

   async operation • Similar with JavaScript’s Promise

4. Ask, and it will be given to you

5. How to implement method which returns Future instance? • Asynchronous

   Method Invocation (Java EE 6) • Creating Asynchronous Methods (Spring Framework)

6. What is CompletableFuture • New class from Java8, implements Future

   interface • Similar with ListenableFuture in Guava and Spring Framework

7. Apply result to Function,

8. or combine them.

9. Merit: connect result of Async I/O seamlessly auth add new

   post load timeline START END
10. None

11. When we use them? • When call async I/O •

    Datastore • Message Queue • Cache • RESTful API

12. Example: When we use them? • If you are service

    provider, • Public service API (interface for user) should return CompletableFuture instance if it may use I/O internally. • Then during I/O is running, your user can use current thread for other usage.

13. Keywords to google • Promise, Future • CompletableFuture • ListenableFuture

    (Guava & Spring Framework) • Function composition