Functional Reactive with Core Java - Workshop - Slides
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The document discusses the importance of user interface and developer productivity in software development, particularly with Vaadin technology. It emphasizes the goals of creating a simple and enjoyable user experience while fostering a consistent brand image. Additionally, it highlights various concepts related to functional programming, Java features, and reactive programming techniques.
Functional Reactive with Core Java - Workshop - Slides
- 1. F U N C T I O N A L - R E A C T I V E @ S V E N R U P P E R T 5 S T O R Y A N D P H I L O S O P H Y Software is eating the world and what most of us see of it is the user interface. The user interface has become the key component of how the users experience the business behind it. Competition is lost or won due to user experience. Simplicity is king and the users get frustrated by anything ugly, slow or not working on the device they happen to use at the time. We at Vaadin fight for simplicity and invite everyone to join this fight. Together we want to build a user interface that puts a smile on the user’s face. Vaadin is the technology that empowers developers to build the best web-apps for business purposes. Our priority over everything else is developer productivity because we believe that by simplifying the developer experience and saving the developer’s time, they are best able to focus on building great user interfaces. Our brand is what we want everyone to think about us. When everyone - both us and the people around us - have a consistent understanding of what Vaadin is and what we stand for, it enables that image to spread and amplify. This book defines what we want that image to be. It defines what the Vaadin brand is. I hope that You are as excited and proud of living and breathing the Vaadin brand as I am. You are the one who is shaping what everyone thinks about Vaadin - using this brand as a tool and a guideline every day. Let’s fight for simplicity for both the users and the developers! Joonas Lehtinen Founder & CEO Vaadin I N T R O D U C T I O N W I T H C O R E J AVA 8 - 11 A N D B E Y O N D
- 2. S V E N R U P P E R T Developer Advocate @ Vaadin 5 C O D I N G J AVA S I N C E 1 9 9 6 C O N S U LT I N G W O R L D W I D E Public Sector: Military / Government Private Sector: Automotive / Aerospace / SMB / NonProfit / NonGov: World Bank / UN / YPARD / CGIAR D I S T R I B U T E D S Y S T E M S S I N C E 2 0 0 2 J O I N E D VA A D I N 2 0 1 7
- 3. I N T R O D I F F E R E N C E S B E T W E E N O O A N D F P I N J AVA
- 4. 4 @SvenRuppertJava8 - Optional<T> the border between OO and FP in Java is not 100% clear.
- 5. @SvenRuppert S I N C E J AVA 8 Functional Interfaces - basics
- 6. 6 @SvenRuppertJava8 - Functional Interfaces
- 7. 7 @SvenRuppertJava8 - Functional Interfaces
- 8. 8 @SvenRuppertJava8 - Functional Interfaces
- 9. 9 @SvenRuppertJava8 - Functional Interfaces
- 10. 10 @SvenRuppertJava9 - Functional Interfaces Java9 - JEP213
- 11. @SvenRuppert E X E R C I S E S S I N C E J AVA 8 Functional Interfaces - basics
- 12. @SvenRuppert S I N C E J AVA 8 Optional<T>
- 16. Optional<T> - since JDK10 @SvenRuppert
- 17. @SvenRuppert E X E R C I S E S S I N C E J AVA 8 Optional<T>
- 18. @SvenRuppert S I N C E J AVA 8 Result<T>
- 19. Optional<T> @SvenRuppert Not symmetric Not async - blocking only Not functional enough Declared final - no inheritance Having ValueTypes in mind We need something
- 20. Result<T> @SvenRuppert Must be easy to transform Optional <-> Result Should work as an Drop-In-Replacement Should connect to the Reactive-World Should be symmetric Must fit functional style / oo style
- 21. Result<T> @SvenRuppert Transform from and to an Optional pos. and neg. available
- 23. @SvenRuppert Handle both ways Async if needed Result<T>
- 24. @SvenRuppert Combine with Value and Transformation Async if needed Result<T>
- 25. @SvenRuppert Combine with Value / Function Async if needed Combine with a function Result<T>
- 26. @SvenRuppert E X E R C I S E S S I N C E J AVA 8 Result<T>
- 27. @SvenRuppert S I N C E J AVA 8 Exceptions
- 39. @SvenRuppert E X E R C I S E S S I N C E J AVA 8 Exceptions
- 40. @SvenRuppert H O W T O U S E F U N C T I O N S … Functions - Basics
- 41. Functions - Java8 41 @SvenRuppert a function is a transformation input -> output (input - type, input value) (output - type, output value)
- 46. 46 @SvenRuppert Compose is not so nice.. but Functions - Java8
- 47. 47 @SvenRuppert Attention : make a semantic equal function !! Functions - Java8
- 48. 48 @SvenRuppertFunctions - Java8 How to get an instance of a function?
- 52. Functions - Java8 - extract the logic ! 52 @SvenRuppert
- 55. @SvenRuppert E X E R C I S E S H O W T O U S E F U N C T I O N S … Functions - Basics
- 56. @SvenRuppert G E N E R I C B A C K A N D F O R WA R D Currying
- 61. @SvenRuppert E X E R C I S E S G E N E R I C B A C K A N D F O R WA R D Currying
- 62. @SvenRuppert P U R E F U N C T I O N A L B E H AV I O R Memoizing
- 74. @SvenRuppert E X E R C I S E S P U R E F U N C T I O N A L B E H AV I O R Memoizing
- 75. @SvenRuppert H O W T O D E C I D E ? Case
- 77. @SvenRuppertCase
- 78. @SvenRuppertCase
- 79. @SvenRuppertCase
- 80. @SvenRuppertCase
- 81. @SvenRuppert E X E R C I S E S H O W T O D E C I D E ? Case
- 82. @SvenRuppert H O W T O U S E , H O W T O B U I L D Streams
- 84. Streams @SvenRuppert A Stream is active after creation want to define a Stream without starting it maybe creating it interactively we need a function ! Function<T, Stream<R>>
- 85. @SvenRuppert E X E R C I S E S H O W T O U S E , H O W T O B U I L D Streams
- 86. Refactoring example based on Java8 @SvenRuppert
- 87. 86 @SvenRuppertJava8 - Functional Interfaces - Example typical legacy implementation
- 88. 87 @SvenRuppertJava8 - Functional Interfaces - Example typical legacy implementation
- 89. 88 @SvenRuppertJava8 - Functional Interfaces - Example
- 90. 89 @SvenRuppertJava8 - Functional Interfaces - Example
- 91. 90 @SvenRuppertJava8 - Functional Interfaces - Example
- 92. 91 @SvenRuppertJava8 - Functional Interfaces - Example
- 93. 92 @SvenRuppertJava8 - Functional Interfaces - Example
- 94. 93 @SvenRuppertJava8 - Functional Interfaces - Example Sourcecode is on github
- 95. Pattern in Java 8/9 how pattern will change… @SvenRuppert
- 97. Virtual Proxy 95 @SvenRuppert public class ServiceProxy implements Service { private Service service = new ServiceImpl(); public String work(String txt) { return service.work(txt); } } What could we change now ? Virtual Proxy: create the Delegator later public class VirtualService implements Service { private Service service = null; public String work(String txt) { if(service == null) { service = new ServiceImpl(); } return service.work(txt); } }
- 98. Virtual Proxy 96 @SvenRuppert public class VirtualService implements Service { private Service service = null; public String work(String txt) { if(service == null) { service = new ServiceImpl(); } return service.work(txt); } } This is NOT ThreadSafe fixed decision for an implementation how to combine it with a FactoryPattern ?
- 99. Virtual Proxy 97 @SvenRuppert if(service == null) { service = new ServiceImpl(); } public interface ServiceFactory { Service createInstance(); } public interface ServiceStrategyFactory { Service realSubject(ServiceFactory factory); }
- 100. Virtual Proxy - Not - ThreadSafe 98 @SvenRuppert if(service == null) { service = new ServiceImpl(); } public class ServiceStrategyFactoryImpl implements ServiceStrategyFactory { Service realSubject; public Service realSubject(final ServiceFactory factory) { if (realSubject == null) { realSubject = factory.createInstance(); } return realSubject; } } private ServiceFactory serviceFactory = ServiceImpl::new;
- 101. Virtual Proxy - Not - ThreadSafe 99 @SvenRuppert if(service == null) { service = new ServiceImpl(); } public class ServiceProxy implements Service { private ServiceFactory serviceFactory = ServiceImpl::new; private ServiceStrategyFactory strategyFactory = new ServiceStrategyFactoryImpl(); public String work(String txt) { return strategyFactory .realSubject(serviceFactory).work(txt); } }
- 102. Virtual Proxy - Show some code…. 100 @SvenRuppert
- 103. Virtual Proxy - Show some code…. 101 @SvenRuppert
- 104. Virtual Proxy - Show some code…. 102 @SvenRuppert
- 105. Virtual Proxy - Show some code…. 103 @SvenRuppert
- 106. Virtual Proxy - Show some code…. 104 @SvenRuppert
- 107. Virtual Proxy - Show some code…. 105 @SvenRuppert
- 108. Virtual Proxy - Show some code…. 106 @SvenRuppert
- 109. Virtual Proxy - Show some code…. 107 @SvenRuppert
- 110. Virtual Proxy - Show some code…. 108 @SvenRuppert
- 111. Virtual Proxy - Show some code…. 109 @SvenRuppert
- 112. Decorator - pre Java8 110 @SvenRuppert
- 113. Decorator - pre Java8 111 @SvenRuppert
- 114. Decorator - pre Java8 112 @SvenRuppert
- 115. Decorator - pre Java8 113 @SvenRuppert
- 119. Decorator - Java8 - modify orig Interface 117 @SvenRuppert
- 120. Decorator - Java8 - DoubleUnaryOperator 118 @SvenRuppert
- 121. Interpreter - pre Java8 119 @SvenRuppert
- 122. Interpreter - pre Java8 120 @SvenRuppert
- 123. Interpreter - pre Java8 121 @SvenRuppert
- 124. Interpreter - pre Java8 122 @SvenRuppert
- 125. Interpreter - Java8 - Java9 123 @SvenRuppert
- 126. Interpreter - Java8 - Java9 124 @SvenRuppert Main Idea - DataStructure to Function
- 127. Interpreter - Java8 - Java9 125 @SvenRuppert
- 128. @SvenRuppert H O W R E A C T I V E W I L L S TA R T Observer
- 132. 130 @SvenRuppertObserver key not needed anymore
- 134. 132 @SvenRuppertObserver H O W T O C H A I N O B S E R V E R ?
- 135. @SvenRuppert E X E R C I S E S H O W R E A C T I V E W I L L S TA R T Observer
- 136. @SvenRuppert H O W T O U S E F U N C T I O N S … A S Y N C … CompletableFuture
- 137. 135 @SvenRuppertJava8 - CompletableFuture Process Thread Fiber CompletionStage CompletionStage CompletionStage
- 140. 138 @SvenRuppert Operator 1 Value A Operator 2a Result Value B Value C Java8 - CompletableFuture
- 144. 142 @SvenRuppertJava8 - CompletableFuture Operator 1 Value A Operator 2a Result Value B Value C
- 145. @SvenRuppert E X E R C I S E S H O W T O U S E F U N C T I O N S … A S Y N C … CompletableFuture
- 146. @SvenRuppert H O W T O C R E AT E A G R A P H E A S Y. . CompletableFutureQueue
- 147. 145 @SvenRuppertCompletableFutureQueue CompletableFuture is active after creation want to define a CompletableFuture without starting it maybe creating it interactively we need a function ! Function<T, CompletableFuture<R>>
- 150. @SvenRuppert E X E R C I S E S H O W T O C R E AT E A G R A P H E A S Y. . CompletableFutureQueue
- 151. Java 9 some nice news… @SvenRuppert
- 153. Java9 - JEP266 150 @SvenRuppert we got Publisher / Subscriber
- 154. @SvenRuppert I N T E R FA C E O R I M P L E M E N TAT I O N ? Var
- 155. @SvenRuppert E X E R C I S E S I N T E R FA C E O R I M P L E M E N TAT I O N ? Var
- 156. Summary X @SvenRuppert places to read more about it www.functional-reactive.org https://github.com/functional-reactive
- 157. Summary 153 @SvenRuppert please, follow me ;-) @SvenRuppert Thank You !!!