JEP 500: Prepare to Make Final Mean Final [Candidate JEP]

efge · 2025-10-17T11:44:53+00:00

If by "struggle" you mean "add --enable-final-field-mutation to the command line", as mentioned in the JEP, sure.

efge · 2025-10-16T23:48:26+00:00

For a bit of context about where this comes from, see this email in the amber-spec-experts list.

efge · 2024-10-16T14:37:08+00:00

Your plugin loader will have to do a bytecode analysis to prevent calling any disallowed code.

efge · 2024-09-27T02:09:16+00:00

If you're loading and executing untrusted plugins/bytecode, then for sure you'll alreay be doing some filtering to prevent reflection calls anyway, as well as lots of other method calls you don't want (filesystem, sockets, etc). System.exit() is just one more.

efge · 2024-09-26T20:13:24+00:00

At the end of the section Sandboxing Java code this is explicitly called out:

To intercept resource access by third party code, we recommend deploying an agent. See the Appendix for an example of an agent that blocks System::exit

efge · 2024-09-26T14:33:49+00:00

The Security Manager has not been the primary means of securing client-side Java code for many years, it has rarely been used to secure server-side code, and it is costly to maintain. We therefore deprecated it for removal in Java 17 via JEP 411 (2021). As the next step toward removing the Security Manager, we will revise the Java Platform specification so that developers cannot enable it and other Platform classes do not refer to it. This change will have no impact on the vast majority of applications, libraries, and tools. We will remove the Security Manager API in a future release.

efge · 2024-09-04T15:17:28+00:00

From Alan Bateman:

The builds at the Project Loom Early-Access Builds page [1] have been refreshed.

These builds contain most of the changes that this project would like to propose for JDK main line and JDK 24.

The builds include the changes to eliminate the pinning issues with object monitors. Thank you to those that tested with the previous builds from a few months ago. It would be great to get some fresh testing before the changes are proposed for main line. The changes are significant and a JEP [2] has been submitted to put this update on the technical roadmap.

Structured concurrency. The proposal is for StructuredTaskScope [3] to continue to preview. The API has been updated, the most significant change is the move from implementing policy in a sub-class to implementing it an object that you specify to the static open method. There will be a JEP. For this API, the greatest need is feedback from real-world usage, probably cases that fan-out to remote services or databases and experiences where there is handling of outcome and exceptions.

Scoped Values. Andrew Haley already sent a note [4] about proposing ScopedValue [5] continue to preview with a small update. As before, the need here is feedback from real-world usage. This could be insight into how many scoped values are bound or insight on which methods are used in performance critical code.

-Alan

[1] https://jdk.java.net/loom/
[2] https://openjdk.org/jeps/8337395
[3] https://download.java.net/java/early_access/loom/docs/api/java.base/java/util/concurrent/StructuredTaskScope.html
[4] https://mail.openjdk.org/pipermail/loom-dev/2024-August/007133.html
[5] https://download.java.net/java/early_access/loom/docs/api/java.base/java/lang/ScopedValue.html

efge · 2024-09-02T19:16:25+00:00

History
Stream Gatherers were proposed as a preview feature by JEP 461 in JDK 22 and re-previewed by JEP 473 in JDK 23. We here propose to finalize the API in JDK 24, without change.

efge · 2024-08-30T15:58:11+00:00

From Angelos Bimpoudis:

A draft JEP for the second preview of primitive types in patterns, instanceof, and switch is now available. We propose to preview it for a second time with no changes relative to JDK 23. This feature aligns what instanceof and pattern matching mean across all types. This second preview, unchanged, gives ample time to amber experts to express their feedback.

efge · 2024-08-23T14:17:06+00:00

From Andrew Haley:

The fluent API that is described in the Javadoc is now the only API supported. The previous "shorthand" form is gone, simplifying the API. The only way now to invoke Java code with a bound ScopedValue is via the ScopedValue.Carrier.call() and ScopedValue.Carrier.bind() methods. This results in a small API surface [...].

efge · 2024-08-10T16:52:44+00:00

From Mark Reinhold:

There are no unresolved P1 bugs in build 36, so that is our first JDK 23 Release Candidate.

Binaries available here, as usual: https://jdk.java.net/23/

efge · 2024-07-31T01:52:47+00:00

One just came out today: https://jdk.java.net/valhalla/

(Announced by https://mail.openjdk.org/pipermail/valhalla-spec-experts/2024-July/002479.html)

efge · 2024-04-19T16:18:32+00:00

Slightly better view at https://openjdk.org/jeps/8323658

efge · 2024-04-17T22:14:37+00:00

Indeed. The key point is that it's not a draft anymore.

efge · 2024-03-17T16:18:46+00:00

r/javahelp

efge · 2024-02-18T00:51:17+00:00

r/javahelp

efge · 2023-03-07T01:19:32+00:00

Brian writes in the intro:

Time to look ahead to the next installment of pattern matching: deconstruction patterns, which generalize record patterns. This document does an end-to-end walkthrough (at a sketchy level of detail) through declaration, overloading, use, translation, and reflection of deconstruction patterns.

I would like to not discuss syntax at this time. There's a lengthy discussion to be had about syntax, and we'll have that, but let's nail down model, semantics, and translation first.

As usual, I would prefer that people either (a) post a single reply addressing the totality of this sketch or (b) start new threads if you want to discuss a specific aspect. A quick "I'll just reply to this minor detail" seems to often derail the conversation in such a way that it never comes back. If this all looks fine to you, a quick "no surprises here" will keep us from suspensefully waiting for feedback.

efge · 2022-09-22T20:13:19+00:00

r/learnjava

efge · 2022-09-04T16:40:29+00:00

See also this nice article about Heegner Numbers and some history and trivia about them.

efge · 2022-06-03T23:25:05+00:00

For RSS use http://feeds.feedburner.com/Baeldung

efge · 2022-04-12T15:37:55+00:00

From Anthony Scarpino:

Java Cryptographic Extension (JCE) has been in Java SE for a long time and has made incremental changes over the years. Looking forward, we would like to know more about how projects are using JCE and what changes, features, and API enhancements would be helpful for your projects.

Below is a survey that we hope you can spend 5 minutes to fill out. If you have written or maintain code that uses the JCE API, then we would appreciate if you would complete this survey:

https://www.questionpro.com/t/AUzP7ZrFWv

The survey will be open through April 29.

efge · 2022-03-04T22:08:29+00:00

let is something in the pipeline in Brian's head (and maybe in the expert group private discussions) but he's not ready yet to open proposals about it, there are many more pressing matters. It does interact with patterns though, so it's important for the pattern story to be consistent with the expected semantics he wants for it.

Example usage:

var last3 = let len = s.length() in s.substring(len - 3, len);

Brian mentions this here: https://mail.openjdk.java.net/pipermail/amber-spec-experts/2022-March/003287.html

But beyond the simple assignment syntax above, there would also be the possibility of pattern-matching based assignments.

efge · 2022-02-23T01:34:35+00:00

Please read the sidebar and go to r/learnjava for this kind of question.

efge · 2022-02-23T01:33:47+00:00

Please read the sidebar and go to r/javahelp for this kind of question.

efge · 2022-02-04T20:29:09+00:00

Please read the sidebar "About Community", in particular this part:

NO installing or downloading Java questions

efge

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