Boost your craftsmanship with Java 8

A short introduction to, and practical experiment of, the new features available to the Java craftsman.

Java 8 is mostly about new functional programming paradigms.

Lambdas, method references and the stream API are powerful and yet sometimes hard to understand concepts. These slides are mainly about describing those features, in a way, that is easy to understand, through, analogies and thought experiments discussions.

Transcript

1. JAVA 8 a short introduction and practical experiment software analyst, 2e systems @joaonunesk boost your craftsmanship
3. Wat?!
5. { … }
7. @FunctionalInterface
8. Should we verbosely create a basic implementation of a simple interface?
9. Or should we briefly create a basic implementation of a simple interface?
10. before after
11. ( Class :: method ) method references
12. • a static method • an instance method of a object • a constructor Reference….
13. If a method expects a functional interface… …and if we have a method that looks like the abstract representation of that functional interface…
14. vs
15. STREAMS
16. filter() map() stream() stream or pipeline input collect() stream or pipeline output filter() mapToInt() post stream or pipeline output getAsDouble() average() sum() anyMatch() filter()
17. java.util.stream.Stream collect map filter sorted anyMatch findAny findFirst count distinct limit
18. java.util.stream.Collectors groupingBy toList summarizingInt toSet partitioningBy minBy toMap
22. java.time.LocalDate java.util.Date and Calendar vs
23. System.out.println(new Date(2016, 06, 06)); ?
24. Thu Jul 06 00:00:00 CEST 3916 time timezone day month year
25. System.out.println(LocalDate.of(2016, 06, 06)); ?
26. 2016-06-06
27. java.time.LocalDateTime java.time.LocalDate java.time.LocalTime java.time.Period java.time.Instant java.time.format.DateTimeFormatter Store and represent Parse and display
29. Drive on the left!
30. Java 8 is much more optionals, default methods, new tools, javascript engines…
31. design for failure?
33. the best craft or nothing