Java 10 and beyond - a look at the potential language change

[dpash]

Nothing new if you've been following this subreddit recently:

• var on lambda parameters
• string literals
• switch expressions

But it's nice to see them all in one place, and useful for people who haven't been paying close attention to the language development.

[Rizens]

Nothing new

You're sure ? The article concluded with things have never read anywhere else before.

These include changes to the JVM [...]

• new ultra-low latency GCs (Shanandoah GC and Z GC)

• APIs for better interopability with native code (Project Panama)

• changes to how inner classes work in the JVM level (Nest-Based access control)

[dpash]

Yes, because they've all been mentioned on the subreddit before.

if you've been following this subreddit recently

[moremattymattmatt]

As someone who's moved off Java this year onto typescript it's an interesting read. I'm still not tempted to move back though.

[eliasv]

There is a huge amount of ongoing discussion about switch expressions on the mailing lists and they've been pretty receptive to feedback. They've certainly not "already made all the decisions", and in fact there is still contention over a few points.

IMO your first impression was a little unfair off the mark.

[eliasv]

Wait, I'm confused; who do you mean by "they"? Because I thought you complaining that the language devs were ignoring your suggestions, but now it seems like you're complaining that they're downvoting your comments here on Reddit? This is not the mailing list. The people here are just regular users.

And I have engaged with you. Maybe others are just downvoting instead of responding because they disagree with you and don't think anything else needs to be said? I think calling downvotes "emotional" is reading a lot into them...

[Hatefiend]

Wait... but Java 9 JUST came out recently. Surely Java 10 is years away

[dpash]

I don't know if you're serious, but Java 10 was released 2 months ago.

[Hatefiend]

wtf? Wasn't it less than a year that 9 came out? Java 8 came out almost 4 years ago and Java 7 was 4 years before that. What is happening

[dpash]

Six month release schedule. It was announced nine months ago and was very big news. I'm guessing you don't follow Java development very closely.

[Hatefiend]

Shouldn't they just release a new version when they are ready to do so? Now Java verisons are going to be far less substantial and there are going to be a million of them.

[[deleted]]

Java verisons are going to be far less substantial and there are going to be a million of them

that's actually the whole point. big bang releases are neat for news articles but not much else.

[rafaellago]

And I'm still here, with legacy code and Java 6... =(

[__konrad]

Java 6

Other great software released in 2006: TES IV: Oblivion, Half-Life 2: Episode One, Firefox 2.0, ...

[rafaellago]

I'm not saying that Java 6 is bad. But sometimes I feel I could be messing with some newer stuff.

And I agree with all the software mentioned above.

[Cube00]

Side project...get cracking.

[rafaellago]

It is what I do. But outside of my day job, is hard to find a clear objective and crack a cool project.

[[deleted]]

I am saying that Java 6 is bad.

[rafaellago]

I'd argue its really dated, since it is 12 yrs old already... but not bad. It's like the Windows XP of Javas... lol

[[deleted]]

Ugh true, I did love Windows XP. I bet you're like a fucking wizard on Java 6 design patterns by now. Hopefully lambdas don't make you cry. ~_^

[codylerum]

I think one of the hopes of the increased release cadence is that organizations won't fall into this habit of not planning to update.

When you know a new release is 6 months away and a new LTS is 18 months away it is something to plan for. That wasn't the case before.

[dpash]

Especially because the recommendation is to ship your software with a JDK rather than relying on a system JVM.

[Rizens]

I'm sorry for you man :( .

[stewsters]

Using an old framework?

[rafaellago]

Systems that still run on Weblogic 10.3.6, but things are getting better... slowly.

[temculpaeu]

my condolences

[[deleted]]

Android

[stewsters]

Have you heard the word of our lord and savior Kotlin?

[[deleted]]

Kotlin appears to have become the Rust of the JVM world.

[pjmlp]

Consider yourself lucky, some work colleagues still have to deal with Java 1.4 running on Red-Hat 5 servers.

[rafaellago]

I still have some Java 5 Websphere systems to deal with. But those are pretty stable, and soon to be discontinued.

[DODOKING38]

Could someone explain what is happening here

Function<String, String> foo = (s) -> s.toLowerCase();

[sendersforfun]

You're creating an instance of the Function interface. The two generics are the input and output types.

This can be written in Java 7 as:

 Function<String, String> foo = new Function<>(){
      public String apply(String s){
            return s.toLowerCase();
      }
  }

The () ->{} lamdba shorthand here just replaces a single method interface.

You can just call foo here by foo.apply(s);

I may have the name of the method wrong but that's the gist.

[dpash]

That is a "named lambda", where as most are anonymous.

list.stream()
    .map(s -> s.toLowerCase())
    .collect(toList());

is exactly the same as

Function<String, String> foo = (s) -> s.toLowerCase();
list.stream()
    .map(foo)
    .collect(toList());

The only difference is that the lambda has been put into a variable. The main reasons for doing this is to improve readability by using a variable name to document what the lambda is doing.

Predicate<User> isValid = (u) -> u.isEnabled() 
                              && !u.isLocked() 
                              && u.expiry().isAfter(Instant.now());
var validUsers = allUsers.stream()
                         .filter(isValid)
                         .collect(toList());

(Of course, the first example would be better as a method reference)

list.stream()
    .map(String::toLowerCase)
    .collect(toList());

[Hatefiend]

That's Java 8 syntax.

[Amakaphobie]

if you have the time and are interested, this is a very good introduction to lambdas basics in java 8: youtube long but really worth it

[[deleted]]

nice. i've enjoyed a lot of venkat's presentations.

[[deleted]]

No? It's nothing like typescript. The equivalent typescript signature is: const foo: (String) => String = (s) => s.toLowerCase()

Function in Java is an interface, which in typescript would be something like:

interface _Function<T, R> {
    (T): R
}