Good day, I try to build .jar file for my server c...

# server

[stask]

Good day, I try to build .jar file for my server code to launch it on the virtual machine.

Jar, built as artifact is launched with error

java -jar server.jar 
Exception in thread "main" java.lang.NoClassDefFoundError: kotlin/jvm/internal/Intrinsics
...

I googled, that the problem is in kotlin library, which should be packed into the jar in a specific way. Documentation here https://www.jetbrains.com/help/idea/create-your-first-kotlin-app.html?section=Gradle%20Groovy tells me, that I should add special code in build.gradle. There is my code on the picture. As you can see, "from" is grey...

And I get next error for Gradle

* Exception is:
org.gradle.api.GradleScriptException: A problem occurred evaluating root project 'server'.
<131 internal calls>
Caused by: org.gradle.internal.metaobject.AbstractDynamicObject$CustomMessageMissingMethodException: Could not find method jar() for arguments [build_c5anurhkrrlxlaf3i7moe4k0u$_run_closure5@7f80db22] on task set of type org.gradle.api.internal.tasks.DefaultTaskContainer.
	at org.gradle.internal.metaobject.AbstractDynamicObject.methodMissingException(AbstractDynamicObject.java:182)
	at org.gradle.internal.metaobject.AbstractDynamicObject.invokeMethod(AbstractDynamicObject.java:166)
	at org.gradle.api.internal.tasks.DefaultTaskContainer_Decorated.invokeMethod(Unknown Source)
	at build_c5anurhkrrlxlaf3i7moe4k0u.run(/Users/stask/projects/motionLearning/chat/kotlinServer/server/build.gradle:100)
	at org.gradle.groovy.scripts.internal.DefaultScriptRunnerFactory$ScriptRunnerImpl.run(DefaultScriptRunnerFactory.java:91)
	... 130 more

Could you help me, how to fix the build?

[Vampire]

I strongly recommend not building a fat jar due to many reasons, some of them being that they are a bad practice abuse of Java functionality that can easily be done wrongly and in some cases even cannot work properly.

Instead you should use the Gradle application plugin to build a proper distribution archive with everything you need (your code, your libs, generated start scripts for Windows and *nix, ...) by just applying one plugin and setting one propertyk https://docs.gradle.org/current/userguide/application_plugin.html

[stask]

Thank you, it is a usefull link. I started to understand building process.

[stask]

@Vampire I read the article, and as I understand, I should add into build.gradle lines

application {
    mainClass = 'broccole.Server'
    executableDir = 'out/bin'
}

and run from cmd
gradle distZip
Am I right?

[Vampire]

If you want the start scripts in out/bin in the final archive, then yes

[stask]

In fact nothing was produced.

I has default kotlin multiplatform build.gradle script, The folder remains empty

[stask]

Little strange, that the default task runs server localy successfully. And that task depends on jvmJar task

jvmJar {
    dependsOn(jsBrowserProductionWebpack)
    from(new File(jsBrowserProductionWebpack.entry.name, jsBrowserProductionWebpack.outputPath))
}

task run(type: JavaExec, dependsOn: [jvmJar]) {
    group = "application"
    main = "broccole.Server"
    classpath(configurations.jvmRuntimeClasspath, jvmJar)
    args = []
}

[stask]

@Vampire So, runnable jar is building on my laptop.
I just want to upload the jar on virtual machine and launch it there.

The simplest way for me - is to find the jar and command to launch, which gradle use on my laptop.
But gradle is not transparent, and I don't see its command line log.

Could you advice, how to see gradle log?

[stask]

Eventually found the solution here: https://stackoverflow.com/questions/57168853/create-fat-jar-from-kotlin-multiplatform-project

Answer from Julian Schubert works for me. The problem is in kotlin multiplatform, application plugin does not work out of the box

@Vampire thank you for your answers!

[stask]

Working solution is next

kotlin {
jvm() {
    withJava()
    jvmJar {
        manifest {
            attributes 'Main-Class': 'broccole.Server'
        }
        from { configurations.runtimeClasspath.collect { it.isDirectory() ? it : zipTree(it) } }
    }
}
...

[Vampire]

Ah, sorry, didn't think the multiplatform plugin is made so incompatible with the application plugin.
To build a proper distribution with the application plugin you indeed need a little bit more boilerplate.
But I would still prefer that anytime over building a fat jar.

I just tried and this should work fine:

application {
    mainClass = 'broccole.Server'
}

def runtimeClasspath = files()
runtimeClasspath.from(configurations.jvmRuntimeClasspath)
runtimeClasspath.from(jvmJar)

run {
    classpath = runtimeClasspath
}

startScripts {
    classpath = runtimeClasspath
}

distributions {
    main {
        contents {
            into('lib') {
                from(runtimeClasspath)
            }
        }
    }
}

It fixes up the run task, the startScripts generation task and the distribution copy spec and thus the installDist, distZip and distTar tasks.

[stask]

@Vampire thank you, I will try your solution and write feedback here.

[stask]

@Vampire I placed you code fragment after jvmJar task, and everything works.

Command "gradle assemble" built server.tar file for me. I unpacked it and ran server/bin/server successfully. Thank you!