Hacker News Reader

Comment by derefr | Hacker News Reader

> I wrote a simple tool that allows you to filter out what you don't need

It'd be a short hop from here to a tool that basically does for JDK-platform apps what Erlang's releases do for the ERTS platform: builds a new JRE (as a portable executable, not an installer) that actually contains the app and its deps in the JRE's stdlib, such that you just end up with a dir containing "a JRE", plus a runtime "boot config" file that tells the JRE what class it should run when you run the JRE executable.

With such a setup, your Java program could actually ship as an executable binary, rather than a jar and an instruction to install Java. Nobody would have to know Java's involved! :)

View on HN

Funny you mention that, that's exactly why we wrote this tool. We were having a ton of support issues with our Windows users having to install Java, incompatible Java versions, needing admin privileges to install the JRE, etc...

We fixed this whole class of issues by doing exactly what you suggest: bundling the JRE and writing our own launcher binary.

Does java license interfere with this kind of setup?

not when you bundle the openjdk

https://docs.oracle.com/javase/8/docs/technotes/guides/deplo...

Not only is it a short hop, it already exists :P

Nice. Here's the manual page, the relevant flag is "-native":

http://docs.oracle.com/javase/8/docs/technotes/tools/unix/ja...

The problem with visiting that site is that Oracle have started litigating against users of their JVMs.

In that way the JVM can be "heavy".

With users that use commercial features without paying for them.

It is quite easy to know which features those are when they require a flag named -XX:+UnlockCommercialFeatures, you just don't use them by mistake.

Oracle gives free license to use commercial features in development[1] in section B. It is very easy to some script for JVM startup parameters and get that script deployed in production by mistake.

1. http://www.oracle.com/technetwork/java/javase/terms/license/...

Quite right, but unless I am too cynical I doubt those deployments were actually done by mistake, when I relate how many companies try to "alleviate" their costs.

Avian [0] is an embeddable VM in the way you suggest, I haven't used it though.

In the future, we'll hopefully have the Substrate VM [1] for Java and other Truffle-supported languages. It's embeddable and also does reachability analysis to exclude unused library code. For now, it seems to be closed source.

[0] http://readytalk.github.io/avian/

[1] http://lafo.ssw.uni-linz.ac.at/papers/2015_CGO_Graal.pdf

> what Erlang's releases do for the ERTS platform

That's the difference between an industrial-strength platform like Erlang, and a dev-centric deployment nightmare like Python. Java is normally on the enterprise side of the spectrum, but unfortunately it didn't get deployment right for quite a long time, even though it appears it's getting there lately.

It started on Java 8 with adoption of having a packing story as part of the JDK tooling, but I don't know how good it is.

Careful there---it's a slippery slope all the way to unikernels.

https://mirage.io/

Isn't that _exactly_ what GoLang does for its binaries, insofar as shipping them statically linked?

dotnetcore has it as an option, as well.

It's called "treeshaking", and is a classic option in Lisp delivery tools.

Or virtual image pruning in Smalltalk tools.

.NET Core does have this and allows distributing the runtime, your classes as a standalone executable. It is obviously larger than just the class files and dlls but works great for portability.

Reply on news.ycombinator.com