JDK 18 Early-Access builds 23 are available

david.delabassee at oracle.com david.delabassee at oracle.com
Wed Nov 17 11:17:46 UTC 2021


I’m happy to announce that moving forward Oracle’s Java DevRel Team will 
manage the Quality Outreach Program. I would like to thank Rory for all 
the efforts he's put into this program and wish him all the joy and 
happiness that retirement can bring! We have big shoes to fill but we’re 
excited to continue building off the amazing structure Rory has put in 

The JDK 18 schedule is now known [1] with a feature freeze date 
(Rampdown Phase One) less than 4 weeks away! This time, we have 2 
important heads-ups, one related to JEP 411 (Deprecate the Security 
Manager for Removal), and one related to JEP 416 (Reimplement Core 
Reflection with Method Handles). We're asking your help to test and 
confirm that your project works seamlessly now that those 2 JEPs are 
integrated in the JDK 18 Early-Access builds.

[1] https://openjdk.java.net/projects/jdk/18/

# JEP 411 - Deprecate the Security Manager for Removal

Starting JDK 18 b21 [2], the default value of the 
'java.security.manager' system property is set to "disallow". This means 
that any application or library that enables the Security Manager by 
calling `System.setSecurityManager` will now have to specify 
`-Djava.security.manager=allow` on the command-line in order for that 
code to continue working as expected. This change was originally 
targeted for JDK 17, but after some discussion/feedback from the 
community, the change was delayed until JDK 18 [3].

[2] https://bugs.openjdk.java.net/browse/JDK-8270380
[3] https://openjdk.java.net/jeps/411#Description

# JEP 416 - Reimplement Core Reflection with Method Handles

JEP 416 [4] reimplements `java.lang.reflect.Method`, 
`java.lang.reflect.Constructor`, and `java.lang.reflect.Field` on top of 
`java.lang.invoke` method handles. Making method handles the underlying 
mechanism for reflection will reduce the maintenance and development 
cost of both the `java.lang.reflect` and `java.lang.invoke` APIs. This 
is solely an implementation change but we encourage you to test your 
project to identify any behavior or performance regressions.

[4] https://openjdk.java.net/jeps/416

OpenJDK 18 Early-Access builds 23 are now available [5], and are 
provided under the GNU General Public License v2, with the Classpath 
Exception. The Release Notes are available [6].

[5] https://jdk.java.net/18/
[6] https://jdk.java.net/18/release-notes

# JEPs integrated to JDK 18, so far:

- JEP 400: UTF-8 by Default https://openjdk.java.net/jeps/400
- JEP 408: Simple Web Server https://openjdk.java.net/jeps/408
- JEP 413: Code Snippets in Java API Documentation 
- JEP 416: Reimplement Core Reflection with Method Handles 
- JEP 418: Internet-Address Resolution SPI https://openjdk.java.net/jeps/418

# JEPs targeted to JDK 18, so far:

- JEP 417: Vector API (Third Incubator) https://openjdk.java.net/jeps/417

# JEPs proposed to target JDK 18, so far:

- JEP 419: Foreign Function & Memory API (Second Incubator) 
- JEP 420: Pattern Matching for switch (Second Preview) 

# Changes in recent builds that maybe of interest:

## Build 23:

- JDK-8275509: ModuleDescriptor.hashCode isn't reproducible across builds
- JDK-8276220: Reduce excessive allocations in DateTimeFormatter
- JDK-8276298: G1: Remove unused G1SegmentedArrayBufferList::add
- JDK-8273922: (fs) UserDefinedFileAttributeView doesn't handle file 
names that are just under the MAX_PATH limit (win)

## Build 22:

- JDK-8271820: Implementation of JEP 416: Reimplement Core Reflection 
with Method Handle
- JDK-8260428: Drop support for pre JDK 1.4 DatagramSocketImpl 
- JDK-8251468: X509Certificate.get{Subject,Issuer}AlternativeNames and 
getExtendedKeyUsage do not throw CertificateParsingException if 
extension is unparseable

## Build 21:

- JDK-8270380: Change the default value of the java.security.manager 
system property to disallow
- JDK-8275319: java.net.NetworkInterface throws java.lang.Error instead 
of SocketException
- JDK-8270490: Charset.forName() taking fallback default value
- JDK-8269336: Malformed jdk.serialFilter incorrectly handled

# Project Loom update

New Project Loom 18-loom+4-273 (2021/11/10) Early-Access builds are 
available [7] with related Javadocs [8].

[7] https://jdk.java.net/loom/
[8] https://download.java.net/java/early_access/loom/docs/api/

These EA builds are provided under the GNU General Public License, 
version 2, with the Classpath Exception and are produced for the purpose 
of gathering feedback. Use for any other purpose is at your own risk. 
Feedback should be send to the `loom-dev` mailing list 

# Topics of Interest:

* New Candidate JEP: 421: Deprecate Finalization for Removal, 
* What Happens to Finalization in JDK 18 and JEP 416 - Inside Java 
Newscast, https://youtu.be/eDgBnjOid-g

Thank you for being a welcomed part of the Quality Outreach program!

David Delabassée / @delabassee

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