Thanks for this!
For the use case you mention it makes perfect sense to do it that way.
Since I don't want to include groovy jars in every jar bundle, I ended
up with this instead:
https://github.com/Alipsa/groovyjar/blob/main/groovyjar
I still think something similar would be nice and useful as part of the
groovy distribution (e.g. when installed by sdkman)
Best regards,
Per
On 2/23/25 01:53, steve.etchel...@gmail.com wrote:
Hi Per,
I have had (very) good luck with a slightly different approach.
Rather than ‘groovy -jar myapp.jar’ I went with ‘java -jar myapp.jar’.
And this had another, somewhat unexpected, benefit. Building my app
with shadowJar <https://gradleup.com/shadow/> (thanks to the help I
received here) it bundled all of groovy, all my library dependencies
(database drivers, etc), and my app into my jar file. As a result, I
don’t even need to install groovy on a target machine – just copy the
one jar file (myapp.jar) to the target machine and run it via ‘java
-jar myapp.jar’ and everything completely works. Of course this
assumes that Java has been installed but that’s pretty ubiquitous
these days and a requirement anyway. And I don’t have to worry about
the version of groovy that happens to be installed on that machine as
the execution will use the version of groovy that is inside my jar file.
You can review a working example of this at
https://github.com/mre-code/groovysql.
Now unfortunately, due to Java’s newer encapsulation direction
<https://dev.java/learn/modules/strong-encapsulation/> (which does
make a lot of sense) I ended up needing to provide a shell wrapper to
provide all of the –add-opens settings required for (older) Java
database drivers (which I use for this app). Now if it weren’t for
those older Java database drivers which are using reflection I would
not need the little shell wrapper and could just use ‘java -jar
groovysql.jar’ (or even the binfmt approach discussed in the groovysql
repository where you can just make the jar file executable and run it
as ‘groovysql’ after removing the .jar extension from the file).
For background, the little shell wrapper is located in
src/main/bin/groovysql in that repository.
So in order to run my app, all that anyone needs to do is to copy my
jar file and the little shell wrapper from the Releases and place them
somewhere in their PATH and it’s ready to run. No groovy install, no
database driver installs, no configuration, just go.
Hope this helps,
Steve
*From:*Per Nyfelt <p...@alipsa.se>
*Sent:* Saturday, February 22, 2025 2:34 PM
*To:* users@groovy.apache.org
*Subject:* Groovy -jar
Hi,
I find myself missing a way to execute groovy jars e.g: `groovy -jar
someapp.jar`. As a workaround i can do something like the following
in bash (error handling etc. omitted)
*#!/usr/bin/env bash*
*# takes a single parameter (the path to the jar file to execute - it
assumes the Main-Class attribute has been set)*
jarName="$1"
mainClass=$(unzip -p "$jarName" "META-INF/MANIFEST.MF" | grep
'Main-Class:' | awk '{ print $2 }' | tr -d '\r')
java -cp $jarName:$GROOVY_HOME/lib/* $mainClass
But it would be nice to support this "natively" in groovy with `groovy
-jar`
Has support for this been discussed before?
Best regards,
Per
