Play VS Graal

My major complain here is that, as far as being a web framework there is precious little information here about the framework. How does this framework scale with multiple requests? What concurrency strategy is it using (threads, processes, actors, etc?). Is this opinionated (it doesn't seem so but it also doesn't say it isn't either). How does this work with popular libraries x,y,z. The full docs have a little bit more information, but not a ton. But mostly there are some cute toy examples and "built in python" and thats about it.

Lets compare this with for example play https://www.playframework.com/ I know from this that it built on Akka, its stateless, aims for predictable resource consumption, has non-blocking io, etc. There is a ton of really important information on what does this web framework actually do that is really important when you are making a choice of a framework.

I have no idea how good this framework is, but besides a few toy examples, I can't see anything that makes me thing "wow this is great I need to use this".

A web application framework for Java/Scala: https://www.playframework.com/

Scala 3 migration isn't as simple as migrating other apps, you can track the work at https://github.com/playframework/playframework/issues/11260

And there are frameworks you can use to make development easier, like Play. And Java has plenty of choices for dependency injection frameworks.

However do note, Play should be perfectly usable as well, and it's still maintained by the community: https://github.com/playframework/playframework/issues/11649

In university I learned a bit of Java, so maybe I could use it professionally I guess?. There were many options to choose from. DropWizard, Spark, Play Framework. But the more documented one in the internet I found was Springboot, besides there were some courses in spanish and some friends that knew something about Springboot, so I give it a chance.

For a backend web server I use Play - https://www.playframework.com/ which I find to be the easiest one as a backend web server. For learning/using spark I found this course from coursera to be very useful. https://www.coursera.org/learn/scala-spark-big-data

Contrary to what vocal Kotlin advocates might believe, Kotlin only matters on Android, and that is thanks to Google pushing it no matter what.

https://spectrum.ieee.org/the-top-programming-languages-2023

https://snyk.io/reports/jvm-ecosystem-report-2021/

And even so, they had to conceed Android and Kotlin on their own, without the Java ecosystem aren't really much useful, thus ART is now updatable via Play Store, and currently supports OpenJDK 17 LTS on Android 12 and later devices.

As for your question regarding numbers, mostly Java 74.6%, C++ 13.7%, on the OpenJDK, other JVM implementations differ, e.g. GraalVM is mostly Java 91.8%, C 3.6%.

https://github.com/openjdk/jdk

https://github.com/oracle/graal

Two examples from many others, https://en.wikipedia.org/wiki/List_of_Java_virtual_machines

Pkl was built using the GraalVM Truffle framework. So it supports runtime compilation using Futurama Projections. We have been working with Apple on this for a while, and I am quite happy that we can finally read the sources!

https://github.com/oracle/graal/tree/master/truffle

Disclaimer: graalvm dev here.

That's pretty interesting. It's not as aggressive as Bee sounds, but the Espresso JVM is somewhat similar in concept. It's a full blown JVM written in Java with all the mod cons, which can either be compiled ahead of time down to memory-efficient native code giving something similar to a JVM written in C++, or run itself as a Java application on top of another JVM. In the latter mode it obviously doesn't achieve top-tier performance, but the advantage is you can easily hack on it using all the regular Java tools, including hotswapping using the debugger.

When run like this, the bytecode interpreter, runtime system and JIT compiler are all regular Java that can be debugged, edited, explored in the IDE, recompiled quickly and so on. Only the GC is provided by the host system. If you compile it to native code, the GC is also written in Java (with some special conventions to allow for convenient direct memory access).

What's most interesting is that Espresso isn't a direct translation of what a classical C++ VM would look like. It's built on the Truffle framework, so the code is extremely high level compared to traditional VM code. Details like how exactly transitions between the interpreter/compiled code happen, how you communicate pointer maps to the GC and so on are all abstracted away. You don't even have to invoke the JIT compiler manually, that's done for you too. The only code Espresso really needs is that which defines the semantics of the Java bytecode language and associated tools like the JDWP debugger protocol.

https://github.com/oracle/graal/tree/master/espresso

This design makes it easy to experiment with new VM features that would be too difficult or expensive to implement otherwise. For example it implements full hotswap capability that lets you arbitrarily redefine code and data on the fly. Espresso can also fully self-host recursively without limit, meaning you can achieve something like what's described in the paper by running Espresso on top of Espresso.

I'm also using GraalVM if that's of any help.

Quarkus is one of Java frameworks for microservices development and cloud-native deployment. It is developed as container-first stack and working with GraalVM and HotSpot virtual machines (VM).

Apologies, I didn't mean to imply DCEVM went poof, just that I was sad it didn't make it into OpenJDK so one need not do JDK silliness between the production one and the "debugging one" since my experience is that's an absolutely stellar way to produce Heisenbugs

And I'll be straight: Graal scares me 'cause Oracle but I just checked and it looks to the casual observer that it's straight-up GPLv2 now so maybe my fears need revisiting: https://github.com/oracle/graal/blob/vm-23.1.0/LICENSE

> to be compiled to a single executable is a strength that Java does not have

I think this is very outdated claim: https://www.graalvm.org/

https://github.com/oracle/graal/issues/7182