Java Language Futures - Spring 2024 Edition

The *Java* *Programming* *Language* is evolving fast! Watch this video for a whirlwind tour of recent changes as well as a peek into the future. Discover the features you’ll be using when coding Java code next year and beyond!

Video recorded during _*Java*_ _*Day™*_ _*London*_

*Tags* #Java #JDK #OpenJDK #InsideJava #programming

[keineangabe]

The pattern showed for AsyncResult<V> looks exactly like a Rust enum, a shortcut to get that kind of thing would be great.

[peacemakerle]

Still crying for the Elvis operator. For business and database logic, this is the most missing Java feature. We don't want to wrap everything in Optional and lambdas.

[greatso]

It took me an embarrassingly long amount of time to userstand that this was not about new features applied to the spring

I really like the new data oriented philosophy. The way to represent future's state with sealed class makes me think of rust's enums !
I wonder if the rest of the APIs will shift this way. I'm thinking about optionnals, and maybe even an error type ?? (Since we still can't handle exceptions in a functionnal way without creating some custom "Try" type. It really is a pain point I experienced

[rtorello]

The "with" thing seems like a great addition to records. I live in Java 11 World right now, but will be moving up to JDK-21, hopefully, soon. I simply do not understand the massive amount of fan-fare about records, although the most interesting concept about that is that all records are "Read-Only" which seems like a reasonable addition. I know that while something (anything, really) is under development it will seem a lot more important to the programmers until they are finally finished with it.

[cobrab]

Why records not return implicity in the accesors a defensive copy of a mutable fields?

[valcron-]

37:50. I fundamentally disagree. You could have made the exceptions on the original signature checked and get the same benefits of the compiler telling you if you miss any case plus:
- Avoids the additional boxing due to the `AsyncResult` type, plus better performance in the happy path
- You get stack traces in the cases of failure (`Failure`, `Timeout` and `Interrupted`)
- You can quickly propagate to the caller unlike `AsyncResult` (no `?` operator or similar)
- Compositions comes for free. If a function `f` throws `X` and function `g` throws `Y`, then a function that calls both functions can throw `X & Y` due to the fact that `throws` supports a union of exceptions. With a sealed interface you don't get that, meaning that the dev now needs to create a wrapper for the result types (see `anyhow` in Rust for example)

I don't think we're gaining anything valuable with this. I would much rather have proper support for Nullable types or a better `catch` clause for multiple exceptions types (syntax sugar on top of multiple `catch` clauses)

[konrad]

AsyncReturn looks great! good to know about that

[delanym]

Whats the benefit of records and sealed interface vs an enum?

[udayaprakashk]

Record pattern matching looks very verbose, why can’t we just shape instanceof Circle c and just use it?

[peacemakerle]

Using records widely here in business logic. But I really dislike that the canonical constructor of public records can not be private. Now, people are exposing constructors which should be private because there are static create-functions or builders which should be used instead.

[millodev]

Why Java is becoming more and more like Scala Language ?

[avalagum]

2:04 "we've been delivering quite a lot". No, that's not a lot. Scala delivered all of those features in one shot.
4:08 Productivity-oriented language features: Scala can pattern-match on lists. I think that's very productive. Java doesn't need to copy Scala if it has better features.
22:11 looking at the 2 aligned arrows on the `case` lines, I wonder if there's any tool that can align those arrows for me (something like scalafmt).
44:21 suppose that record A contains record B which contains record C ... which contains record Z. Now I want to create a new instance of A from another instance of A where a field in the record Z changes its value, how do I write that?
Does "record with" create more garbage for the GC to collect that a mutable class?

[simonmassey]

I thought string templating just got dropped? (which is actually a success story in a way)

[JoeBrigAI]

“Only use immutable data”, my database would like a word.

[ricardojlrufino]

AsyncResult is useless ... Try .. catch will be more clean .

I will forced to implementar all egde cases ? ( Timeout and interrupted )

[guttormvik]

Record still pisses me of. Start with a record. Then you need mutable state, so you have to change it to a class, and then you have to add in all the junk code that records got for free.

[bluemeriadoc]

33:12 lol, guy has never heard of multicatch from Java 7

[BloodnutXcom]

Java is ancient in terms of features. All of this presentation is just copying the low hanging fruit of Scala which is a JVM language - 10 years later!

Talk about "last mover advantage"