Running a Kotlin application from a build.gradle.kt script

Question

I have build.gradle.kts file, I am trying to define a task which will call a Kotlin function to load a SQL script.

tasks.register("dbTestDataLoader", JavaExec::class) {
    println("Running db test data")

    // starts postgresql service
    dependsOn("startPostgres")

    // run SQL
    main = "com.org.business.DbTestDataLoader"
}

However this gives me an error:

Task :dbTestDataLoader FAILED Error: Could not find or load main class com.org.business.DbTestDataLoader

I've tried adding:

sourceSets["main"].withConvention(org.jetbrains.kotlin.gradle.plugin.KotlinSourceSet::class) {
    kotlin.srcDir("src/main/kotlin")
}

And I've tried using src.main.kotlin.com.business as the source, but either way I get the mentioned error.

This is my file structure:

application-name
    build.gradle.kts
    - src
        - main
            - kotlin
                - com
                    - org
                        - business
                            - DbTestDataLoader.kt

Here is my DbTestDataLoader.kt file:

open class DbTestDataLoader {
    /*fun main(args : Array<String>) {
        println("hello world")
    }*/

    companion object {
        @JvmStatic
        open fun main(cmdArgs: Array<String>) {
            println("Hello World")
        }
    }
}

Edit

Following the answer posted I placed the file inside build/src, but still get the same error.

So my layout not looks like this (.gradle and build were auto generated):

application-name
    buildSrc
        .gradle
        build
        DbTestDataLoader.kt
    src
        ...

Here's the results when I add --stacktrace to the call:

> Task :dbTestDataLoader FAILED
Error: Could not find or load main class DbTestDataLoader

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':dbTestDataLoader'.
> Process 'command 'C:\Program Files\Java\jdk1.8.0_202\bin\java.exe'' finished with non-zero exit value 1

* Try:
Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Exception is:
org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':dbTestDataLoader'.
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$2.accept(ExecuteActionsTaskExecuter.java:121)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$2.accept(ExecuteActionsTaskExecuter.java:117)
        at org.gradle.internal.Try$Failure.ifSuccessfulOrElse(Try.java:184)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:110)
        at org.gradle.api.internal.tasks.execution.ResolveIncrementalChangesTaskExecuter.execute(ResolveIncrementalChangesTaskExecuter.java:84)
        at org.gradle.api.internal.tasks.execution.ResolveTaskOutputCachingStateExecuter.execute(ResolveTaskOutputCachingStateExecuter.java:91)
        at org.gradle.api.internal.tasks.execution.ResolveBeforeExecutionStateTaskExecuter.execute(ResolveBeforeExecutionStateTaskExecuter.java:74)
        at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecuter.java:58)
        at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptySourceFilesTaskExecuter.java:109)
        at org.gradle.api.internal.tasks.execution.ResolveBeforeExecutionOutputsTaskExecuter.execute(ResolveBeforeExecutionOutputsTaskExecuter.java:67)
        at org.gradle.api.internal.tasks.execution.ResolveAfterPreviousExecutionStateTaskExecuter.execute(ResolveAfterPreviousExecutionStateTaskExecuter.java:46)
        at org.gradle.api.internal.tasks.execution.CleanupStaleOutputsExecuter.execute(CleanupStaleOutputsExecuter.java:93)
        at org.gradle.api.internal.tasks.execution.FinalizePropertiesTaskExecuter.execute(FinalizePropertiesTaskExecuter.java:45)
        at org.gradle.api.internal.tasks.execution.ResolveTaskExecutionModeExecuter.execute(ResolveTaskExecutionModeExecuter.java:94)
        at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:57)
        at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:56)
        at org.gradle.api.internal.tasks.execution.CatchExceptionTaskExecuter.execute(CatchExceptionTaskExecuter.java:36)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.executeTask(EventFiringTaskExecuter.java:63)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:49)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:46)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:416)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:406)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor$1.execute(DefaultBuildOperationExecutor.java:165)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:250)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:158)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor.call(DefaultBuildOperationExecutor.java:102)
        at org.gradle.internal.operations.DelegatingBuildOperationExecutor.call(DelegatingBuildOperationExecutor.java:36)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter.execute(EventFiringTaskExecuter.java:46)
        at org.gradle.execution.plan.LocalTaskNodeExecutor.execute(LocalTaskNodeExecutor.java:43)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:355)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:343)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:336)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:322)
        at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker$1.execute(DefaultPlanExecutor.java:134)
        at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker$1.execute(DefaultPlanExecutor.java:129)
        at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.execute(DefaultPlanExecutor.java:202)
        at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.executeNextNode(DefaultPlanExecutor.java:193)
        at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.run(DefaultPlanExecutor.java:129)
        at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:63)
        at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:46)
        at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:55)
Caused by: org.gradle.process.internal.ExecException: Process 'command 'C:\Program Files\Java\jdk1.8.0_202\bin\java.exe'' finished with non-zero exit value 1
        at org.gradle.process.internal.DefaultExecHandle$ExecResultImpl.assertNormalExitValue(DefaultExecHandle.java:396)
        at org.gradle.process.internal.DefaultJavaExecAction.execute(DefaultJavaExecAction.java:37)
        at org.gradle.api.tasks.JavaExec.exec(JavaExec.java:81)
        at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:103)
        at org.gradle.api.internal.project.taskfactory.StandardTaskAction.doExecute(StandardTaskAction.java:48)
        at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:41)
        at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:28)
        at org.gradle.api.internal.AbstractTask$TaskActionWrapper.execute(AbstractTask.java:705)
        at org.gradle.api.internal.AbstractTask$TaskActionWrapper.execute(AbstractTask.java:672)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$4.run(ExecuteActionsTaskExecuter.java:338)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:402)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:394)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor$1.execute(DefaultBuildOperationExecutor.java:165)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:250)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:158)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:92)
        at org.gradle.internal.operations.DelegatingBuildOperationExecutor.run(DelegatingBuildOperationExecutor.java:31)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:327)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:312)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.access$200(ExecuteActionsTaskExecuter.java:75)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$TaskExecution.execute(ExecuteActionsTaskExecuter.java:158)
        at org.gradle.internal.execution.impl.steps.ExecuteStep.execute(ExecuteStep.java:46)
        at org.gradle.internal.execution.impl.steps.CancelExecutionStep.execute(CancelExecutionStep.java:34)
        at org.gradle.internal.execution.impl.steps.TimeoutStep.executeWithoutTimeout(TimeoutStep.java:69)
        at org.gradle.internal.execution.impl.steps.TimeoutStep.execute(TimeoutStep.java:49)
        at org.gradle.internal.execution.impl.steps.CatchExceptionStep.execute(CatchExceptionStep.java:34)
        at org.gradle.internal.execution.impl.steps.CreateOutputsStep.execute(CreateOutputsStep.java:49)
        at org.gradle.internal.execution.impl.steps.SnapshotOutputStep.execute(SnapshotOutputStep.java:42)
        at org.gradle.internal.execution.impl.steps.SnapshotOutputStep.execute(SnapshotOutputStep.java:28)
        at org.gradle.internal.execution.impl.steps.CacheStep.executeWithoutCache(CacheStep.java:133)
        at org.gradle.internal.execution.impl.steps.CacheStep.lambda$execute$5(CacheStep.java:83)
        at org.gradle.internal.execution.impl.steps.CacheStep.execute(CacheStep.java:82)
        at org.gradle.internal.execution.impl.steps.CacheStep.execute(CacheStep.java:37)
        at org.gradle.internal.execution.impl.steps.PrepareCachingStep.execute(PrepareCachingStep.java:33)
        at org.gradle.internal.execution.impl.steps.StoreSnapshotsStep.execute(StoreSnapshotsStep.java:38)
        at org.gradle.internal.execution.impl.steps.StoreSnapshotsStep.execute(StoreSnapshotsStep.java:23)
        at org.gradle.internal.execution.impl.steps.SkipUpToDateStep.executeBecause(SkipUpToDateStep.java:95)
        at org.gradle.internal.execution.impl.steps.SkipUpToDateStep.lambda$execute$0(SkipUpToDateStep.java:88)
        at org.gradle.internal.execution.impl.steps.SkipUpToDateStep.execute(SkipUpToDateStep.java:52)
        at org.gradle.internal.execution.impl.steps.SkipUpToDateStep.execute(SkipUpToDateStep.java:36)
        at org.gradle.internal.execution.impl.DefaultWorkExecutor.execute(DefaultWorkExecutor.java:34)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:109)
        ... 37 more

score 1 · Accepted Answer · answered Feb 17 '20 at 08:27

1

The folder src/main/kotlin is meant for application code, that you want to build (jar, war or whatever)

Code that supports building or testing should be separated from application code, since you don't want to deliver it together with your actual artifact.

If you want to use kotlin code during the build (not merely compile or package it), place it under buildSrc/ as explained in the docs.

answered Feb 17 '20 at 08:27

Frank Neblung

3,047
17
34

Thanks, I ended up using your resource along with: https://kotlinexpertise.com/execute-kotlin-scripts-with-gradle/ – dustytrash Feb 17 '20 at 15:20

Running a Kotlin application from a build.gradle.kt script

1 Answers1