As Velhas Novas do Java 7

Transcript

1. Java 7 as velhas novas do
2. Java 6: Dec 2006 Java 7: Jul 2011 Java 8: Mar 2014 História
3. Lambdas, Jigsaw, e parte do Project Coin foram dropados do Java 7
4. Agenda • Diamond Operator • Strings em Switch’s • Automatic Resource Management • Numeric Literals com Underscores • Exception Handling (multi-catch) • NIO 2.0 • Fork and Join • invokedynamic
5. Diamond Operator // java 6 Map<String, List<String>> list6 = 
 new TreeMap<String, List<String>>(); // java 7 Map<String, List<String>> list7 = new TreeMap<>();
6. String em Switch’s // java 6 AnEnum a = AnEnum.A; switch (a) { case A: doSomethingWhenA(); break; // … }
7. String em Switch’s // java 7 String b = "b"; switch(b) { case "b": doSomethingWhenB(); break; // … }
8. Automatic Resource Management // java 6 BlahResource resource; try { resource = new BlahResource(); resource.doSomething(); } catch (Exception e) { log.error( “Maoeee”, e ); } finally { try { resource.close(); } catch (BlahResourceException e) { log.error( “Ah haee”, e ); } }
9. Automatic Resource Management // java 7 try (BlahResource resource = new BlahResource()) { resource.doSomething(); } catch (Exception e) { log.error( “Maoeee”, e ); }
10. Numeric Literals // java 6 int thousand = 1000; // java 7 int thousand = 1_000;
11. Exception Handling // java 6 try { oneThousandCheckedExceptionsLater(); } catch (ExceptionOne e) { log.error(“Erro: ", e); } catch (ExceptionTwo e) { log.error(“Erro: ", e); } catch (ExceptionThree e) { log.error(“Erro: ", e); }
12. Exception Handling // java 7 try { oneThousandCheckedExceptionsLater(); } catch (ExceptionOne | ExceptionTwo | ExceptionThree e) { log.error(“Erro:”, e); }
13. NIO 2.0 • Path & Paths • Files • FileSystems • WatchService
14. Fork and Join • Dividir para conquistar • ForkJoinTask & ForkJoinPool
15. incokedynamic • Recurso da JVM para suportar melhor linguagens com tipagem dinâmica • java.lang.invoke
16. PROTIPS™
18. GRÁTIS NA LOJA KINDLE!
19. Bom e velho Javadoc ☕️
20. Dúvidas?
21. Thanks https://speakerdeck.com/caarlos0/as-velhas-novas-do-java-7