Refactoring to (effective and modern) Java 11

¡Java 11 ya esta aquí! Y Joshua Bloch ha publicado su tercera edición de “effective java”. Partiendo de ejemplos de proyectos en producción, y basándonos en las recomendaciones de Bloch y otros expertos, repasaremos algunos de los items que más aparecen en el día a día. Haremos especial hincapié en los patterns y 'best practices' a utilizar para no incurrir en un código vulnerable. Si buscas explicaciones detalladas sobre las nuevas funcionalidades de java, cómo usarlas, cuándo elegirlas frente a otras, ¡esta es tu charla!

Video: https://youtu.be/NCvW8-HZIGg

Transcript

1. MAD · NOV 23-24 · 2018 Refactoring to (effective and modern) Java 11 Aurea Programando desde Madrid Katia Programando desde París MAD · NOV 23-24 · 2018
2. MAD · NOV 23-24 · 2018
3. MAD · NOV 23-24 · 2018 Agenda Java 11 Interfaces Optionals Lambdas Streams Modules Conclusions
4. MAD · NOV 23-24 · 2018
5. MAD · NOV 23-24 · 2018 Agenda Java 11 Interfaces Optionals Lambdas Streams Modules Conclusions
6. MAD · NOV 23-24 · 2018 1995
7. MAD · NOV 23-24 · 2018 1995
8. MAD · NOV 23-24 · 2018 1995
9. MAD · NOV 23-24 · 2018 1995
10. MAD · NOV 23-24 · 2018 1995
11. MAD · NOV 23-24 · 2018 1995
12. MAD · NOV 23-24 · 2018 1995
13. MAD · NOV 23-24 · 2018 1995
14. MAD · NOV 23-24 · 2018 2011 2014 2017 2018 2019 7.0 8.0 9.0 10 11 12 13 2006 6.0 Cambio soporte de Oracle
15. MAD · NOV 23-24 · 2018
16. MAD · NOV 23-24 · 2018 Para entender el cambio de licencia Trisha Gee, evangelist Jet Brains https://blog.jetbrains.com/idea/2018/09/using-java-11-in-p roduction-important-things-to-know/ Stephen Colebourne, Joda man https://blog.joda.org/2018/09/time-to-look-beyond-oracles- jdk.html?m=1 Simone Bordet, Jetty, Charla Voxxed Days Ticino 2018 https://youtu.be/cUqcSFLnk_E
17. MAD · NOV 23-24 · 2018 Migrar a java 11 Compilar … compila, pero...
18. MAD · NOV 23-24 · 2018 Agenda Java 11 Interfaces Optionals Lambdas Streams Modules Conclusions
19. MAD · NOV 23-24 · 2018 default void mySuperMethod() { // Enjoy the 1000 lines of code }
20. MAD · NOV 23-24 · 2018 default void mySuperMethod() { // Enjoy the 1000 lines of code } Java 9: Private methods!!
21. MAD · NOV 23-24 · 2018 Person Woman Man Animal Dog Cat
22. MAD · NOV 23-24 · 2018 Person Woman Man Animal Dog Cat Cat Woman
23. MAD · NOV 23-24 · 2018 Person Woman Man Animal Dog Cat Cat Woman
24. MAD · NOV 23-24 · 2018 Interfaces - default methods java 8 default V merge(K key, V value, BiFunction<? super V, ? super V, ? extends V> remappingFunction) { Objects.requireNonNull(remappingFunction); Objects.requireNonNull(value); V oldValue = get(key); V newValue = (oldValue == null) ? value : remappingFunction.apply(oldValue, value); if(newValue == null) { remove(key); } else { put(key, newValue); } return newValue; }
25. MAD · NOV 23-24 · 2018 Interfaces - default methods java 8 default V merge(K key, V value, BiFunction<? super V, ? super V, ? extends V> remappingFunction) { Objects.requireNonNull(remappingFunction); Objects.requireNonNull(value); V oldValue = get(key); V newValue = (oldValue == null) ? value : remappingFunction.apply(oldValue, value); if(newValue == null) { remove(key); } else { put(key, newValue); } return newValue; } public interface Cache<K, V> extends AsyncCache<K, V>, ConcurrentMap<K, V> {
26. MAD · NOV 23-24 · 2018 Interfaces - default methods java 8 V merge(K key, V value, BiFunction<? super V, ? super V, ? extends V> remappingFunction) { assertKeyNotNull(key); assertValueNotNull(value); assertFunctionNotNull(remappingFunction); ReadWriteKeyCommand<K, V, V> command = commandsFactory.buildReadWriteKeyCommand(key, new MergeFunction<>(value, remappingFunction, metadata), keyPartitioner.getSegment(key), Params.fromFlagsBitSet(flags), getKeyDataConversion(), getValueDataConversion()); return executeCommandAndCommitIfNeeded(contextBuilder, command, 1); } public interface Cache<K, V> extends AsyncCache<K, V>, ConcurrentMap<K, V> {
27. MAD · NOV 23-24 · 2018 Item 21: Design interfaces for posterity
28. MAD · NOV 23-24 · 2018 Item 21: Design interfaces for posterity
29. MAD · NOV 23-24 · 2018 Agenda Java 11 Interfaces Optionals Lambdas Streams Modules Conclusions
30. MAD · NOV 23-24 · 2018 La promesa ... “Use optional as a better alternative to null”
31. MAD · NOV 23-24 · 2018 Item 55: Return optionals judiciously
32. MAD · NOV 23-24 · 2018 Patterns for adopting optionals - getting
33. MAD · NOV 23-24 · 2018 Patterns for adopting optionals - getting
34. MAD · NOV 23-24 · 2018 Patterns for adopting optionals - extracting with map I
35. MAD · NOV 23-24 · 2018 Patterns for adopting optionals - extracting with map II
36. MAD · NOV 23-24 · 2018 Patterns for adopting optionals - extracting with map III
37. MAD · NOV 23-24 · 2018 Optionals - API Improvements
38. MAD · NOV 23-24 · 2018 Patterns for adopting optionals - getting
39. MAD · NOV 23-24 · 2018 Optionals - API Improvements
40. MAD · NOV 23-24 · 2018 Optionals - API Improvements
41. MAD · NOV 23-24 · 2018 Optionals - API Improvements
42. MAD · NOV 23-24 · 2018 Optionals - API Improvements
43. MAD · NOV 23-24 · 2018 Optionals - API Improvements
44. MAD · NOV 23-24 · 2018 Optionals - API Improvements
45. MAD · NOV 23-24 · 2018 Optionals - API Improvements
46. MAD · NOV 23-24 · 2018 Optionals - API Improvements
47. MAD · NOV 23-24 · 2018 Optionals - API Improvements
48. MAD · NOV 23-24 · 2018 Optionals - API Improvements
49. MAD · NOV 23-24 · 2018 Optionals - API Improvements
50. MAD · NOV 23-24 · 2018 Anti - patterns
51. MAD · NOV 23-24 · 2018 Anti - patterns
52. MAD · NOV 23-24 · 2018 Agenda Java 11 Interfaces Optionals Lambdas Streams Modules Conclusions
53. MAD · NOV 23-24 · 2018 Collections.sort(words, new Comparator<String>() { public int compare(String s1, String s2) { return Integer.compare(s1.length(), s2.length()); }); Collections.sort(words, (s1, s2) -> Integer.compare(s1.length(), s2.length()));
54. MAD · NOV 23-24 · 2018 Item 42: Prefer lambdas to anonymous classes Lambdas - where use it
55. MAD · NOV 23-24 · 2018 Execute around pattern
56. MAD · NOV 23-24 · 2018 Execute around pattern
57. MAD · NOV 23-24 · 2018 Execute around pattern 1
58. MAD · NOV 23-24 · 2018 Execute around pattern 1 2
59. MAD · NOV 23-24 · 2018 Execute around pattern 1 2 3
60. MAD · NOV 23-24 · 2018 Item 44: Favor the use of standard functional interfaces
61. MAD · NOV 23-24 · 2018 Common functional interfaces added in java 8
62. MAD · NOV 23-24 · 2018 Execute around pattern with standard FI 1
63. MAD · NOV 23-24 · 2018 Execute around pattern with standard FI 1 2
64. MAD · NOV 23-24 · 2018 Execute around pattern with standard FI 1 2 3
65. MAD · NOV 23-24 · 2018 Item 43: Prefer method references to lambdas
66. MAD · NOV 23-24 · 2018 Execute around pattern
67. MAD · NOV 23-24 · 2018 Execute around pattern
68. MAD · NOV 23-24 · 2018
69. MAD · NOV 23-24 · 2018 Conditional Deferred Execution if (trace) { log.trace(format("LOCK[%s] Result is null on request %s",getName(),toString())); } Infinispan 1200
70. MAD · NOV 23-24 · 2018 Conditional Deferred Execution trace(format("LOCK[%s] Result is null on request %s", getName(), toString())); public void trace(String message){ if (trace) { log.trace(message); } }
71. MAD · NOV 23-24 · 2018 Conditional Deferred Execution trace(() -> format("LOCK[%s] Result is null on request %s", getName(),toString())); public void trace(Supplier<String> messageSupplier){ if (trace) { log.trace(messageSupplier.get()); } }
72. MAD · NOV 23-24 · 2018 Factory Pattern Offer offer1 = OfferFactory.createOffer(OfferType.ADSL); Offer offer2 = OfferFactory.createOffer(OfferType.FIBER); Offer offer3 = OfferFactory.createOffer(OfferType.PHONE); List<Offer> offers = Arrays.asList(offer1, offer2, offer3); for (Offer offer: offers) { System.out.println(offer.price()); }
73. MAD · NOV 23-24 · 2018 Factory Pattern public class OfferFactory { public static Offer createOffer(OfferType offerType) { Offer offer; switch (offerType) { case ADSL: offer = new InternetADSL(); break; case FIBER: offer = new InternetFiber(); break; ... default: throw new IllegalArgumentException("Offer type wrong"); } return offer; } }
74. MAD · NOV 23-24 · 2018 Factory Pattern Offer offer1 = OfferFactory.createOffer(OfferType.ADSL); Offer offer2 = OfferFactory.createOffer(OfferType.FIBER); Offer offer3 = OfferFactory.createOffer(OfferType.PHONE); List<Offer> offers = Arrays.asList(offer1, offer2, offer3); for (Offer offer: offers) { System.out.println(offer.price()); }
75. MAD · NOV 23-24 · 2018 Factory Pattern - Java 11 var offer1 = OfferFactory.createOffer(OfferType.ADSL); var offer2 = OfferFactory.createOffer(OfferType.FIBER); var offer3 = OfferFactory.createOffer(OfferType.PHONE); List<Offer> offers = List.of(offer1, offer2, offer3); for (var offer: offers) { System.out.println(offer.price()); }
76. MAD · NOV 23-24 · 2018 Factory Pattern - Java 11 var offer1 = OfferFactory.createOffer(OfferType.ADSL); var offer2 = OfferFactory.createOffer(OfferType.FIBER); var offer3 = OfferFactory.createOffer(OfferType.PHONE); List<Offer> offers = List.of(offer1, offer2, offer3); for (var offer: offers) { System.out.println(offer.price()); }
77. MAD · NOV 23-24 · 2018 Factory Pattern - Java 11 OfferFactory factory = OfferFactory.factory(builder -> { builder.add(OfferType.ADSL, () -> new InternetADSL(20)); builder.add(OfferType.FIBER, InternetFiber::new); builder.add(OfferType.PHONE, Phone::new); }); var offer1 = factory.createOffer(OfferType.ADSL); var offer2 = factory.createOffer(OfferType.FIBER); var offer3 = factory.createOffer(OfferType.PHONE); for (var offer: offers) { System.out.println(offer.price()); }
78. MAD · NOV 23-24 · 2018 Factory Pattern - Java 11 public interface OfferFactory { interface Builder { void add(OfferType offerType, Supplier<Offer> supplier); } static OfferFactory factory(Consumer<Builder> consumer) { Map<OfferType, Supplier<Offer>> map = new HashMap<>(); consumer.accept(map::put); return offerType -> map.get(offerType).get(); } Offer createOffer(OfferType offerType); }
79. MAD · NOV 23-24 · 2018 Factory Pattern - Java 11 public interface OfferFactory { interface Builder { void add(OfferType offerType, Supplier<Offer> supplier); } static OfferFactory factory(Consumer<Builder> consumer) { Map<OfferType, Supplier<Offer>> map = new HashMap<>(); consumer.accept(map::put); return offerType -> map.get(offerType).get(); } Offer createOffer(OfferType offerType); } public interface Function<T, R> { R apply(T t); ...
80. MAD · NOV 23-24 · 2018 Agenda Java 11 Interfaces Optionals Lambdas Streams Modules Conclusions
81. MAD · NOV 23-24 · 2018
82. MAD · NOV 23-24 · 2018 Item 46: Prefer side-effect-free functions in streams
83. MAD · NOV 23-24 · 2018 Streams anti pattern
84. MAD · NOV 23-24 · 2018 Streams anti pattern
85. MAD · NOV 23-24 · 2018 Streams anti pattern
86. MAD · NOV 23-24 · 2018 Item 47: Prefer Collection to Stream as a return type
87. MAD · NOV 23-24 · 2018 Stream API improvements takeWhile() dropWhile() iterate() ofNullable()
88. MAD · NOV 23-24 · 2018 Stream API improvements
89. MAD · NOV 23-24 · 2018 Agenda Java 11 Interfaces Optionals Lambdas Streams Modules Conclusions
90. MAD · NOV 23-24 · 2018 Jigsaw - 10 años - < 9 = Classpath Hell - Móviles, Cloud …
91. MAD · NOV 23-24 · 2018 module-info.java module org.infinispan.multimap { exports org.infinispan.multimap.api.embedded; requires org.infinispan.common; requires org.infinispan.core; }
92. MAD · NOV 23-24 · 2018 module-info.java module org.infinispan.multimap { exports org.infinispan.multimap.api.embedded; requires transitive org.infinispan.core; }
93. MAD · NOV 23-24 · 2018 module-info.java open module org.infinispan.multimap { exports org.infinispan.multimap.api.embedded; requires transitive org.infinispan.core; }
94. MAD · NOV 23-24 · 2018 module-info.java module org.infinispan.core { exports org.infinispan.manager.impl to org.infinispan.multimap.impl; requires org.infinispan.common; }
95. MAD · NOV 23-24 · 2018 Item 15: Minimize the accessibility of classes and members
96. MAD · NOV 23-24 · 2018 Item 15: Minimize the accessibility of classes and members
97. MAD · NOV 23-24 · 2018
98. MAD · NOV 23-24 · 2018 Agenda Java 11 Interfaces Optionals Lambdas Streams Modules Conclusions
99. MAD · NOV 23-24 · 2018 Una lista no exhaustiva de más Java 11 (+9+10) CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=400793 CORBA, SOAP ...
100. MAD · NOV 23-24 · 2018 Una lista no exhaustiva de más Java 11 (+9+10)
101. MAD · NOV 23-24 · 2018 Java 12 String literals (http://openjdk.java.net/jeps/326) Switch statements -> Pattern matching … (http://openjdk.java.net/jeps/325) String html = `<html> <body> <p>Hello World.</p> </body> </html> `; String html = "<html>\n" + " <body>\n" + " <p>Hello World.</p>\n" + " </body>\n" + "</html>\n"; int numLetters = switch (day) { case MONDAY, FRIDAY, SUNDAY -> 6; case TUESDAY -> 7; case THURSDAY, SATURDAY -> 8; case WEDNESDAY -> 9; };
102. MAD · NOV 23-24 · 2018
103. MAD · NOV 23-24 · 2018 1 ? 2 ? 3 ? +3 ?
104. MAD · NOV 23-24 · 2018 Feedback @karesti @karesti_codes @aureamunoz @auritamh