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[Completable] Future](https://cdn.statically.io/img/image.slidesharecdn.com/backtothefuture-16x9-170522180358/75/Back-to-the-Completable-Future-1-2048.jpg)
Back to the [Completable] Future
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- 2. Intro { "name":"Sophia", "job":"Java developer", "employer":"N-iX", "experience":"2+ years" } ImageURL: https://cdn-images-1.medium.com/max/800/1*oZA7pTY3OqNYGBO9xcuIJQ.jpeg
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- 5. Why now? Era of… ImageURLs: http://img.clipartall.com/free-mini-images-arts-clip-art-mixing-bowl-clipart-648_603.gif Mash-up apps
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- 7. What for? Speed upthe application... Image URL: https://www.thewebmaster.com/media/uploads/files/why-carry-out-a-speed-test-on-website_UczLvGZ.jpg
- 8. What for? ... ina simpler way than working directly with threads Image URL: http://static.codeceo.com/images/2015/01/33095007e134e8630fe35771795f3ac8.jpg
- 9. So, we needto do asynchronous programming …
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- 12. Speeding up URLs: http://www.wanicreative.com/wp-Imagecontent/uploads/2015/04/HiRes-1200x800.jpg;http://www.effevicomunicazione.it/sitenew/wp-content/uploads/2015/08/hairglam1.jpg Concurrency Parallelismvs.
- 13. Concurrency Multiple tasks make progressat the same time Time CPU
- 14. Concurrency Time In concurrency, tasks do competefor processor time
- 15. Parallelism Each task is brokeninto sub tasks which can be processed in parallel CPU 1 CPU 2 Time
- 16. Parallelism Time In parallelism, tasks donot compete for processor time
- 17. Variations Image URLs: https://graphicpolicy.files.wordpress.com/2014/11/back-to-the-portal.jpg?w=350&h=200&crop=1;https://cache.popcultcha.com.au/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/d/e/delorean- back-to-future-hove-time-amachine-electronic-vehicle-replica-14-dstfeb172621.png
- 18. Concurrency is an illusionof parallelism, don‘t you agree?
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- 21. Well, it canbe Is asynchronous any faster?
- 22. Sync vs. Async Theadvantage is obvious, isn't it? Image URL: https://image.slidesharecdn.com/javainhft-141222112349-conversion-gate02/95/java-in-high-frequency-trading-23-638.jpg?cb=1419247883, http://www.pngall.com/wp-content/uploads/2016/04/Red-Cross-Mark-Transparent.png
- 23. Sync vs. Async Makeyour calls non-blocking! Image URL: https://s-media-cache-ak0.pinimg.com/600x315/09/60/a3/0960a3cf49ff2c1a23e8b67997b17be6.jpg
- 24. So, what aboutJava?
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- 26. Java retirement party Howit used to be… Image URL: https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcTAc9Up87H315tKinSkf8EZ8VfoR46gZfDGR2SjTCG_yOwAJvJ8MA • Threads • Future<T> • ForkJoinPool • Streams (parallel)
- 27. Threads Thread 1 Thread2 Object 1 Object 2 Image URL: https://s-media-cache-ak0.pinimg.com/originals/09/1b/f8/091bf88ab19547360376dc24014addfd.gif;https://cdn4.iconfinder.com/data/icons/meBaze-Freebies/512/lock.png
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- 29. Threads Image URL: https://avaldes.com/wp-content/uploads/2013/03/multithreading_starvation.png?2d262d,http://blog.takipi.com/wp-content/uploads/2014/05/Blog_key_.png. http://blog.takipi.com/wp-content/uploads/2013/08/blog_trampoline.png
- 30. Callables & Future<T> ImageURL: http://www.deadcoderising.com/content/images/2015/Jan/timeout2.png
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- 32. Parallel streams Splitting Parallelprocessing Combining
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- 34. More… ◦ Chain callbacks ◦Wait for completion ◦ Retrieve the value ◦ Complete a Future ◦ React & Recover
- 35. CF: let's getacquainted!7
- 36. CompletableFuture ◦ java.util.concurrent Image URL:http://cdn.ishaya.ir/ponila_bucket/images/00/17/00175721ebb9add9498d86bda11e0ec0/736x/00175721ebb9add9498d86bda11e0ec0.jpg ◦ implements Future<T> ◦ implements CompletionStage<T>
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- 38. Concept Brings the conceptof promises to Java. Image URL: https://pbs.twimg.com/media/CzTp1YBW8AEFAMI.jpg
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- 40. API: Simplest asynchronouscomputation ◦ Pitfall #1: Specify custom executor to avoid using default common pool. Image URL: http://cdn.ishaya.ir/ponila_bucket/images/00/17/00175721ebb9add9498d86bda11e0ec0/736x/00175721ebb9add9498d86bda11e0ec0.jpg
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- 42. API: Chaining callbacks ◦Pitfall #2: Use thenCompose instead of thenApply to avoid the nestings. Image URL: http://cdn.ishaya.ir/ponila_bucket/images/00/17/00175721ebb9add9498d86bda11e0ec0/736x/00175721ebb9add9498d86bda11e0ec0.jpg
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- 44. API: Parallel computations ◦Pitfall #3: Keep in mind that the order of execution is not guaranteed. Image URL: http://cdn.ishaya.ir/ponila_bucket/images/00/17/00175721ebb9add9498d86bda11e0ec0/736x/00175721ebb9add9498d86bda11e0ec0.jpg
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- 46. API: Dealing withmany CompletableFuture instances ◦ Pitfall #4: We get CompletableFuture<Void> as the result of execution of all futures. Image URL: http://cdn.ishaya.ir/ponila_bucket/images/00/17/00175721ebb9add9498d86bda11e0ec0/736x/00175721ebb9add9498d86bda11e0ec0.jpg
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- 48. API: Dealing withmany CompletableFuture instances ◦ Pitfall #5: We get CompletableFuture<Object> as the result of execution of the fastest future. Image URL: http://cdn.ishaya.ir/ponila_bucket/images/00/17/00175721ebb9add9498d86bda11e0ec0/736x/00175721ebb9add9498d86bda11e0ec0.jpg
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- 50. API: Exceptions ◦ Pitfall#6: Exceptions can not be handled with usual CompletableFuture methods. Image URL: http://cdn.ishaya.ir/ponila_bucket/images/00/17/00175721ebb9add9498d86bda11e0ec0/736x/00175721ebb9add9498d86bda11e0ec0.jpg
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- 52. Java 9 concurrencyimprovements JEP 266: More Concurrency Updates 8 new methods; 5 new static methods. Image URL: https://ilaborie.github.io/devfest-toulouse-16-slides/pictures/Java9.png
- 53. Java 9 concurrencyimprovements: API Additions orTimeout(long timeout, TimeUnit unit) Image URL: https://ilaborie.github.io/devfest-toulouse-16-slides/pictures/Java9.png
- 54. Java 9 concurrencyimprovements: API Additions completeOnTimeout(T value, long timeout, TimeUnit unit) Image URL: https://ilaborie.github.io/devfest-toulouse-16-slides/pictures/Java9.png
- 55. Java 9 concurrencyimprovements: API Additions completeAsync(Supplier<? extends T> supplier, Executor executor) Image URL: https://ilaborie.github.io/devfest-toulouse-16-slides/pictures/Java9.png
- 56. Java 9 concurrencyimprovements: API Additions completeAsync(Supplier<? extends T> supplier) Image URL: https://ilaborie.github.io/devfest-toulouse-16-slides/pictures/Java9.png
- 57. Java 9 concurrencyimprovements: API Additions defaultExecutor() Image URL: https://ilaborie.github.io/devfest-toulouse-16-slides/pictures/Java9.png
- 58. Java 9 concurrencyimprovements: API Additions newIncompleteFuture() Image URL: https://ilaborie.github.io/devfest-toulouse-16-slides/pictures/Java9.png
- 59. Java 9 concurrencyimprovements: API Additions copy() Image URL: https://ilaborie.github.io/devfest-toulouse-16-slides/pictures/Java9.png
- 60. Java 9 concurrencyimprovements: API Additions minimalCompletionStage() Image URL: https://ilaborie.github.io/devfest-toulouse-16-slides/pictures/Java9.png
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- 62. Java 9 concurrencyimprovements: Static API Additions ◦ Executor delayedExecutor(long delay, TimeUnit unit, Executor executor) ◦ Executor delayedExecutor(long delay, TimeUnit unit) Image URL: https://ilaborie.github.io/devfest-toulouse-16-slides/pictures/Java9.png
- 63. Java 9 concurrencyimprovements: Static API Additions ◦ <U> CompletionStage<U> completedStage(U value) ◦ <U> CompletionStage<U> failedStage(Throwable ex) ◦ <U> CompletableFuture<U> failedFuture(Throwable ex) Image URL: https://ilaborie.github.io/devfest-toulouse-16-slides/pictures/Java9.png
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- 65. Takeaways understand the input; avoidthe pitfalls; use Java 9 before the release!
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- 67. Thanks! Find me at sophia.khomyn@gmail.com https://github.com/KhomynSophia/completable-future COMPLETABLEFUTUREOVERVIEW http://javaday.org.ua/completablefuture-overview/
- 68. CREDITS Special thanks toall the people who made and released these awesome resources for free: ◦ Presentation template by SlidesCarnival