2018-QCon-Java-11.pdf

@jeanneboyarsky Java 11 – Keeping the Java Release Train on
the Right Track speakerdeck.com/boyarsky Jeanne Boyarsky QCon– June 28, 2018

@jeanneboyarsky So much changed since Java 9 & Jigsaw’s release!
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@jeanneboyarsky 3

@jeanneboyarsky For more on Java 9, see: https://speakerdeck.com/ boyarsky/welcome-to- java-9?slide=1
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@jeanneboyarsky Topics: •  Ecosystem changes •  Language changes 5

@jeanneboyarsky About Me 16 years as Java Developer 6

@jeanneboyarsky Memories! 7

@jeanneboyarsky Til Java 6 (1996- 2006) Hi Oracle (2010) Java
7 (2011) Java 8 (2014) Java 9 (2017) 8

@jeanneboyarsky The Saga of Jigsaw •  2011 – Maybe part
of Java 7. Nope Plan B •  2012 - Part of Java 8. No wait •  2014 - Part of Java 9 9

@jeanneboyarsky Java 9 “Release” Dates •  Sept 2016 •  May
2017 •  July 2017 •  Sept 2017 10

@jeanneboyarsky Counting lessons? •  1.0, 1.1, 1.2, 1.3, 1.4 • 
5.0 •  6, 7, 8, 9, 10, 11 11

@jeanneboyarsky Advanced counting lessons •  10 = 2018.3 •  11
= 2018.9 •  12 = ? 12

@jeanneboyarsky Wait, a major version every 6 months? •  +
Syntax changes •  + Smaller features •  - Years of features JDK 10 JDK 11 12 new features 15 new features 13

@jeanneboyarsky Java School Report Card Developer Community à A Features
à B Frequency of Release à F Predictability of Release à D 14

@jeanneboyarsky JVM College Report Card Vocabulary à B Polyglot programming
à A Frequency of Release à F Predictability of Release à D 15

@jeanneboyarsky Re-org at the train station 16

@jeanneboyarsky How many languages do you know? q  One (or
zero) q  Two – Five q  Six or more Examples •  Java •  Kotlin •  Groovy •  Scala •  SQL •  HTML •  JavaScript •  CSS 17

@jeanneboyarsky Before Now 18

@jeanneboyarsky Before Now 19

@jeanneboyarsky Before Now Releases every Varies 6 months (or 3
years) Releases are Feature driven Date driven 20

@jeanneboyarsky More time to code while I wait for the
next train! 21

@jeanneboyarsky Arrivals Train Schedule Java Release Date Long Term Support
9 September 21, 2017 10 March 20, 2018 11 September 25, 2018 22

@jeanneboyarsky Security Patches Departure Schedule Java Public Patches Paid Patches
6 2013 Late 2018 7 2015 2022 8 January 2019 (business) December 2020 (public) 2025 23

@jeanneboyarsky Security Patches Departure Schedule Java Public patches Paid patches
9 March 2018 n/a 10 September 2018 n/a 11 March 2019 2023-2028 24

@jeanneboyarsky Wait. So what happens next? How long will Java
12 have security patches? Answer: 6 months What is the next LTS version after Java 11? Java 11 + 3*2 = 17 25

@jeanneboyarsky A Tale of Two JDKs Java Oracle JDK Open
JDK New Version Every 3 years Every 6 months Cost Paid Free Upgrade Options •  Security patch •  Next version •  OpenJDK •  Interim security patch •  Next version 26

@jeanneboyarsky Only bug fixes remain Only bug fixes allowed 27

@jeanneboyarsky Get ready to play 28

@jeanneboyarsky Tip: Aliases alias javac11=/Library/Java/JavaVirtualMachines/ jdk-11.jdk/Contents/Home/bin/javac alias java11=/Library/Java/JavaVirtualMachines/ jdk-11.jdk/Contents/Home/bin/java 29

@jeanneboyarsky LOCAL VARIABLE SYNTAX (10/11) 30

@jeanneboyarsky String name = "Jeanne”; var name = "Jeanne"; List
list = List.of(1, 2, 3); var list = List.of(1, 2, 3); •  Syntactical sugar/less boilerplate •  Not immutable (no val) (10) 31

@jeanneboyarsky var name = "Jeanne"; String name2 = name; • 
Compiled code same with var (10) 32

@jeanneboyarsky List<WebElement> headers = thead.findElements(By.tagName("th")); VolunteerDashboardRow headerRow = new VolunteerDashboardRow(headers);
vs var headers = thead.findElements(By.tagName("th")); var headerRow = new VolunteerDashboardRow(headers); (10) 33

@jeanneboyarsky var csvPath = createAndGetFile(CSV_DATA); try (var csvWriter = Files.newBufferedWriter(csvPath);
var csvPrinter = new CSVPrinter(csvWriter, CSVFormat.DEFAULT)); { } (10) 34

@jeanneboyarsky Map<Integer, String> productMap1 = new HashMap<Integer, String>(); Map<Integer, String>
productMap2 = new HashMap<>(); var productMap3 = new HashMap<Integer, String>(); (10) 35

@jeanneboyarsky Where can we use? var name = "Jeanne"; var
other = name + 2; var list = List.of(1, 2, 3); for (var num : list) {} (10) 36

@jeanneboyarsky Where can’t we use? class Inner { var bad
= "abc"; } var noGood; noGood = 4; •  Also instance variables, etc (10) 37

@jeanneboyarsky Does this work? var var = "var"; (10) 38

@jeanneboyarsky (10) Pros Cons Less typing Loss of information Less
redundancy Variable names matter more Can scan variable names Be careful! 39 http://openjdk.java.net/projects/amber/LVTIstyle.html

@jeanneboyarsky Lambdas Predicate<String> pred1 = p -> true; Predicate<String> pred2
= (String p) -> true; Predicate<String> pred3 = (var p) -> true; (11) 40

@jeanneboyarsky Annotations BiPredicate< Map<Integer, String>, List<String>> func = (@NotNull var
map, var list) -> true; (11) 41

@jeanneboyarsky All or nothing Good (var map, var list) ->
true No good (var map, list) -> true (var map, List list) -> true (11) 42

@jeanneboyarsky GARBAGE COLLECTION (10/11) 43

@jeanneboyarsky Choose your own GC •  Who cares? •  Agile.
With releases every 6 months, features are smaller (10) 44

@jeanneboyarsky Faster Default GC Java 8 Parallel Garbage Collector Java
9 G1 GC Java 10 + 11 G1 GC with parallel implementation (10) For more, see https://speakerdeck.com/cguntur/garbage- collection-in-java-9 45

@jeanneboyarsky Regions & space vs speed (10) For more, see
https://speakerdeck.com/cguntur 46

@jeanneboyarsky Epsilon GC (11) •  Never reclaims memory •  Program
proceeds until run out of heap •  GC never runs •  To use: •  -XX:+UseEpsilonGC •  (or) -XX:+UseNoGC 47

@jeanneboyarsky Epsilon GC Good for (11) •  Performance/memory stress test
•  Very short programs •  Last ditch performance improvements (this probably isn’t you) 48

@jeanneboyarsky Z GC (11) •  Experimental •  10ms or less
pause time •  Only for Linux/x64 •  To use, enable both: •  -XX:+UnlockExperimentalVMOptions •  -XX:+UseZGC 49

@jeanneboyarsky HTTP CLIENT (11) I’m done incubating! 50

@jeanneboyarsky (11) var uri = "http://www.google.com"; var client = HttpClient.newHttpClient();
var request = HttpRequest.newBuilder() .uri(URI.create(uri)) .build(); var response = client.send(request, BodyHandlers.ofString()); System.out.println(response.body()); 51

@jeanneboyarsky (11) var client = HttpClient.newHttpClient(); var requests = uris.stream()
.map(HttpRequest::newBuilder) .map(reqBuilder -> reqBuilder.build()) .collect(toList()); CompletableFuture.allOf(requests.stream() .map(r->client.sendAsync(r, ofString())) .toArray(CompletableFuture<?>[]::new)) .join(); 52

@jeanneboyarsky Other APIs •  BodyHandlers – file, inputstream, string, discarding
•  Request Builder Options – Header, proxy, authenticator, http protocol version •  Methods – get/post/put/delete (11) 53

@jeanneboyarsky TIME BASED VERSIONING (10) 54

@jeanneboyarsky String javaVersion = System.getProperty("java.version"); Runtime.Version version = Runtime.Version.parse(javaVersion); System.out.println(javaVersion
+ ": " + version.feature() + " " + version.interim() + " " + version.update() + " " + version.patch()); (10) 55

@jeanneboyarsky (10) 10.0.1 11-ea [deprecated] major() 10 11 [deprecated] minor()
0 0 [deprecated] security() 1 0 56

@jeanneboyarsky (10) 10.0.1 11-ea feature() 10 11 interim() 0 0
update() 1 0 patch() 0 0 57

@jeanneboyarsky (10) Updates Examples feature() Every 6 months 10, 11,
12 interim() n/a for Open JDK 0 update() Within 6 months 0, 1, 2 patch() Emergencies 0, 1, 2 58

@jeanneboyarsky System.out.println( System.getProperty("java.version.date")); (10) 10.0.1 11-ea 2018-04-17 2018-09-25 Yes, the
future! 59

@jeanneboyarsky System.out.println( System.getProperty("java.version.version")); •  Null for Open JDK •  For
vendor use (10) Yes, version is here twice! 60

@jeanneboyarsky ODDS AND ENDS 61

@jeanneboyarsky New java launcher mode Full command Shorthand javac HelloWorld.java
java HelloWorld java HelloWorld.java Produces class file Fully in memory For any program For programs with one class (11) 62

@jeanneboyarsky Unmodifiable Collections (10) 63 Copying another Terminal operations List.copyOf
Collectors.toUnmodifiableList Set.copyOf Collectors.toUnmodifiableSet Map.copyOf Collectors.toUnmodifiableMap

@jeanneboyarsky Behind the Scenes •  Nest based access control • 
Remove hack for private access in nested classes •  Pay off tech debt (11) 64

@jeanneboyarsky JDK Java EE/Corba Modules Java 9 Java 11 (11)
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@jeanneboyarsky Pack200 Tools Java 11 à Use jlink to compress packages
(11) 66

@jeanneboyarsky Nashorn Java 11 •  Challenging to maintain •  Unclear
adoption •  May be adopted •  Made it into Java 11 two days before cutoff (11) 67

@jeanneboyarsky Unicode 9 and 10 Support Languages + emoji (10+11)
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@jeanneboyarsky Tying it all together (10+11) 69 import java.nio.charset.*; public
class Unicode { public static void main(String... args) { System.out.print("Have a \uD83C\uDF7A"); System.out.println(" or a \uD83E\uDD64"); } }

2018-QCon-Java-11.pdf

2018-QCon-Java-11.pdf

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