The document outlines the release model for Java, highlighting the introduction of a 6-month cycle for feature releases and the long-term support for JDK 11. It discusses key features from JDK 10 and JDK 11, including improvements in garbage collection, introduction of new APIs, and changes to language syntax. Additionally, it mentions the ongoing support and transition from older Java versions while emphasizing different support options like Oracle JDK, OpenJDK, and Azul's Zulu.

1. Java 10まとめと、どうなる
Java 11
2018/5/26 JJUG CCC 2018
Spring
きしだ なおき

2. About me
• Naoki Kishida
• LINE Fukuoka
• @kis

3. Agenda
• New Release Model
• About JDK 10
• About JDK 11
• About Java Support

4. New Release Model

5. 6-monthly release
• Oracle had announced they will
release Java every 6 months at
2017/9/6

6. Java new release cycle.
• Feature release every 6 months
– March and September(春分の⽇/秋分の⽇)
• Maintenance release every 3 months
– April and July for March release
– October and January for September release
• Long Term Support every 3 years
– The first LTS is for JDK 11
• Oracle JDK will be for only Oracle
Customer
– Use OpenJDK instead.

7. Version number
• 2018/03 Feature release JDK10
• 2018/04 Maintenance release JDK10.0.1
• 2018/07 Maintenance release JDK10.0.2
• 2018/09 Feature release JDK11 LTS
• 2018/10 Maintenance release JDK11.0.1
LTS
• 2019/01 Maintenance release JDK11.0.2
LTS

8. Java SE 8 support is extended
• Oracle has extended Java SE 8
support at least until 2019/1
• It is available for the personal use
until 2020/12
• Java SE 8 support will finish after 3
months of JDK 11 release.
• We should move to JDK 11 by 2019/1
http://www.oracle.com/technetwork/jp/java/eol-135779-ja.html

9. Desktop technology
• Applet and Web Start is no longer
supported after JDK 11
• JavaFX will not be bundled with JDK11
– So far OpenJDK had not bundled JavaFX
• AWT and Swing will be supported
– There are many commits for JDK 11

10. About JDK 10

11. Java 10 JEPs
• 286 Local-Variable Type Inference
• 296 Consolidate the Repository
• 304 GC Interface
• 307 Paralell Full GC for G1
• 310 Application Class-Data Sharing
• 312 Thread-Local Handshakes
• 313 Remove javah
• 314 Additional Unicode Language-Tag Extensions
• 316 Heap Allocation on Alternative Momory Devices
• 317 Experimental Java-Based JIT Compiler
• 319 Root Certificates
• 322 Time-Based Release Versioning

12. 286: Local-Variable Type
Inferences
• var list = new ArrayList<String>()
• `var` is not a keyword
– but a special type
• We can use `var` as a variable name
• We can use `var` as a method name
• We can not use `var` as a class name

13. Usage for `var`
• var m = new Object() {
int twice(int x) {
return x * 2;
}
};
print(m.twice(3));

14. 304: Garbage-Collector
Interface
• GC is modularized.
• There are many GCs that will come.
– Epsilon GC
– ZGC
– Shenandoah
• Not to control GC by user code

15. 317: Experimental Java-Based
JIT Compiler
• Project Metoropolis
– java-on-java
• We can write JVM even with Scala?
– There is a possibility.

16. 307: Parallel Full GC for G1
• G1GC had been the default GC on JDK
9
• Full GC for G1 was not parallel.
• Until JDK 8, Parallel GC was the
default
• To smooth migration, Full GC for
G1GC also parallelize.
• But full GC should not occur.
– Ideally, it has no effect for us.

17. 310: Application Class-Data
Sharing
• CDS for system class is introduced in
JDK 5
• Share class data between multiple
JVM
on the same machine
– startup performance
– reduce the resource footprint
• JDK 10 allow to use CDS for
application class

18. 312: Thread-Local Handshakes
• JVM can stop an individual thread
– stop not just all thread

19. 314: Additional Unicode
Language-Tag Extentions
• Enhance java.util.Locale
• additional Unicode extensions
of BCP 47 language tag
– currency type
– the first day of the week
– region override
– time zone

20. 316: Heap Allocation on
Alternative Memory Devices
• Now we can use non-volatile RAM(不
揮発性メモリ) such as 3D XPoint
• This will enable the JVM to use
different types of memory system

21. 319: Root Certificates
• OpenJDK doesnʼt have Root
Certificates so far
• Oracle JDK have had it.
• To smooth migration, OpenJDK have
had it.

22. API Changes
• java.io.Reader
– long transferTo(Writer)
• java.lang.mainagement.RuntimeMXBe
an
– long getPid()
• java.util.List/Map/Set
– copyOf(Collection)
• java.util.stream.Collectors
– toUnmodifiableList/Set/Map

23. Docker aware
• Until JDK 9, JVM use the platform CPU
count/Memory size even if it is running
on Docker.
• JDK 10, JVM can use Docker setting for
CPU count/ Memory size if it is running
on Docker.
• VM Options
– -XX:InitialRAMPercentage
– -XX:MaxRAMPercentage
– -XX:MinRAMPercentage

24. Other Changes
• Kerberos configuration file krb5.conf
include *.conf in INCLUDEDIR
• -d32 and –d64 has been removed
• new JavaDoc tag. {@summary}
• policytool has been removed
• XMLInputFactory.newFactory() has
been “de-deplicated”
– it had been deplicated by mistake.

25. About JDK 11

26. Java 11 JEPs
• 309 Dynamic Class-File Constants
• 318 Epsilon: A No-Op Garbage Collector
• 320 Remove the Java EE and CORBA Modules
• 321 HTTP Client(Standard)
• 323 Local-Variable Syntax for Lambda Parameters
• 324 Key Agreement with Curve25519 and Curve448
• 327 Unicode 10
• 328 Flight Recorder
• 329 ChaCha20 and Poly1305 Cryptographic Algorithms
• 330 Launch Single-File Source-Code Programs

27. Expected JEPs for JDK11
• 326 Raw String Literals
• 325 Switch Expressions
• 181 Nest-Based Access Control

28. Launch Single-File Source-Code
Programs
• java Hello.java
• Shebang
– #! /usr/bin/java –source 10
– chmod +x hello
– ./hello

29. Raw String Literals
• var sql = ```select NAME
from MEMBER
where id=1```
• How to address indent

30. Switch Expressions
• Now `switch` is a statement
• int i;
switch (s) {
case “start”:
case “begin”:
i = 0;
break;
case “end”:
i = 1;
break;
default:
i = 2;

31. Switch Expressions
• int i = switch (s) {
case “start”,“begin”-> 0;
case “end” -> 1;
default -> 2;
}

32. Local-Variable Syntax for
Lambda Parameters
• list.map(s -> s.toUpperCase())
.collect(toList())
• list.map((var s) -> s.toUpperCase())
.collect(toList())

33. HTTP Client(Standard)
• Guraduate the incubate
• var client HttpClient.newHttpClient();
var url = URI.create(url);
var req = HttpRequest.newBuilder(uri).build();
HttpResponse<String> res = client.send(
req, HttpResponse.BodyHandlers.ofString(
Charset.forName(“utf-8”));
return res.body();

34. Epsilon: A No-Op Garbage
Collector
• Do nothing!
• For evaluate GC performance

35. Remove the Java EE and
CORBA Modules
• No one uses CORBA!
• The size is large
• Removing them, JDK will be smaller

36. Flight Recorder
• Logging the performance
• Now it is an open source

37. Unicode 10
• Support Unicode 9 and Unicode 10

38. Nestmate
• To address inner class accesivility
• Valhalla!

39. Java 11でのAPI追加
• String
– repeat
– lines
– isBlank
– strip/stripLeading/stripTrailing

40. String
• repeat
• isBlank
• lines
• strip/stripLeading/stripTrailing

41. Predicate::not
• lines.filter(s -> !s.isEmpty())
→
lines.filter(Predicate.not(String::isEmp
ty))

42. Files
• String Files.read(Path)
• Path FIles.write(Path, String)
• Files.isSameContent(Path, Path)

43. ArrayIndexOutOfBoundsException
• jshell> new int[]{}[0]
| java.lang.ArrayIndexOutOfBoundsException thrown: 0
| at (#1:1)
->
jshell> new int[]{}[0]
| Exception java.lang.ArrayIndexOutOfBoundsException:
Index 0 out of bounds for length 0
| at (#8:1)

44. How about Stream#toList？
• modifiable? unmodifible?
• What order?
• “it nulls a property of the Stream API
we have take time to keep.
The whole Stream API doesn't
depends on the Collection API”

45. About Java Support

46. Oracle JDK
• Same as the current support
• Very expensive for web servicer
• 100 servers on AWS -> 1おくえん

47. OpenJDK
• Official publishment says it has only 6
months support for each JDK release.
No LTS
• Mark Reinhold said OpenJDK will have
LTS
– but not on the web site yet
– LTS support is for 3 years. No overlap.

48. AdoptOpenJDK
• Project by London JUG
• IBM suponsered
• Provide pre-build JDK
• LTS support for 4 years

49. Zulu
• Provided by Azul System
• Free to download and use
• Enterprise support
– 100 servers $28,750/year
– unlimited servers $258,750/year

50. Support the new era
after Heisei
• Start to support the new era as
NewEra
• JDK12 will release 2019/3
• The new era will release early 2019/4
• JDK maintenance release will be late
2019/4
– JDK 12.0.1
• The new era will start 2019/5

51. Summary
• がんばろ