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

2. So much changed since Java 9 & Jigsaw’s release!
Duke from:
PowerPoint Jigsaw from:

3.
What version of Java 11, 10, 9, …

4. https://speakerdeck.com/boyarsky/welcome-to-java-9?slide=1
For more on Java 9, see:
PowerPoint Jigsaw from:

5. Topics: Ecosystem changes Language changes

6. About Me
16 years as
Java Developer

7. Memories!
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Thought cloud from:

8. Java 8 (2014) Java 9 (2017) Java 7 (2011) Hi Oracle Til (2010) Java 6
(1996-
2006) Hi
Oracle
(2010)
Java 7
(2011)
Java 8
(2014)
Java 9
(2017)
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9. The Saga of Jigsaw 2011 – Maybe part of Java 7. Nope Plan B
Part of Java 8. No wait
Part of Java 9
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10. Java 9 “Release” Dates Sept 2016 May 2017 July 2017 Sept 2017
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11. Counting lessons?
1.0, 1.1, 1.2, 1.3, 1.4
5.0
6, 7, 8, 9, 10, 11
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12. Advanced counting lessons
10 =
11 =
12 = ?
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13. Wait, a major version every 6 months?
JDK 10
JDK 11
12 new features
15 new features
+ Syntax changes
+ Smaller features
- Years of features
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14. Predictability of Release  D Developer Community  A Features  B
Frequency of Release
 F
Predictability of Release
 D
Java School
Report Card
Developer Community
 A
Features
 B

15. Predictability of Release  D Vocabulary  B Polyglot programming  A
Frequency of Release
 F
Predictability of Release
 D
JVM College
Report Card
Vocabulary
 B
Polyglot programming
 A

16. Re-org at the train station
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Thought cloud from:

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

18. Before
Now
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Cover: full stack, QCon, DevNexus

19. Before
Now
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Cover community ownership

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

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

22. Arrivals Train Schedule
Java
Release Date
Long Term Support 9
September 21, 2017 10
March 20, 2018 11
September 25, 2018
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23. Security Patches Departure Schedule
Java
Public Patches
Paid Patches 6
2013
Late 2018 7
2015
2022 8
January 2019 (business)
December 2020 (public)
2025
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24. Security Patches Departure Schedule
Java
Public patches
Paid patches 9
March 2018
n/a 10
September 2018 11
March 2019
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25. 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 *2 = 17

26. 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

27. Only bug fixes remain Only bug fixes allowed

28. Get ready to play

29. 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

30. Local variable syntax (10/11)
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31. (10)
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)

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

33. (10)
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);
Point out scanability

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

35. (10)
Map<Integer, String> productMap1 = new HashMap<Integer, String>(); Map<Integer, String> productMap2 = new HashMap<>(); var productMap3
Not always less typing

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

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

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

39. Variable names matter more
(10)
Pros
Cons
Less typing
Loss of information
Less redundancy
Variable names matter more
Can scan variable names
Be careful!

40. (11)
Lambdas
Predicate<String> pred1 = p -> true; Predicate<String> pred2 = (String p) -> true; Predicate<String> pred3 = (var p) -> true;
Useful for annotation

41. (11)
Annotations
BiPredicate< Map<Integer, String>, List<String>> func = var map, var list) -> true;
Useful for annotation

42. (11)
All or nothing
Good (var map, var list) -> true No good (var map, list) -> true (var map, List list) -> true
Useful for annotation

43. Garbage collection (10/11)
(permission from Chandra to reuse image)

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

45. Faster Default GC (10) Java 8 Parallel Garbage Collector Java 9 G1 GC
G1 GC with parallel implementation
For more, see

46. Regions & space vs speed
(10)
Regions & space vs speed
For more, see
Slide from

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

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

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

50. Http Client (11) I’m done incubating!
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51. (11)
var uri = " 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());

52. (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();
From

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

54. Time Based Versioning (10)
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55. (10)
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());

56. (10)
10.0.1
11-ea
[deprecated] major() 10 11
[deprecated] minor()
[deprecated] security() 1

57. (10)
10.0.1
11-ea
feature() 10 11
interim()
update() 1
patch()

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

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

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

61. Odds and Ends
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62. New java launcher mode (11) 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

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

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

65. JDK Java EE/Corba Modules
(11)
JDK Java EE/Corba Modules
Java 11
Java 9
Deprecated
for removal!
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66. Deprecated for removal!
(11)
Pack200 Tools
Java 11
Use jlink to
compress packages
Deprecated
for removal!
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67. Deprecated for removal!
(11)
Nashorn
Java 11
Deprecated
for removal!
Challenging to maintain
Unclear adoption
May be adopted
Made it into Java 11
two days before cutoff
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68. Unicode 9 and 10 Support Languages + emoji (10+11) 🦒 🦔 🛸 🛷 🥨 🥤 🤛 🤜
Beware: didn’t show on my work computer

69. Tying it all together (10+11) 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"); }
java11 Unicode.java
Have a 🍺 or a 🥤

70. No need to be puzzled.
Java 11 LTS
6 months
New features
Go tell your manager/team to be ready for September!

71. ???