I figured it out:
The GroovyShell belongs to the parent classloader and thus ginq cannot find it
when the classloader lacks a parent. One solution is to use the parentless
classloader to create the GroovyShell e.g:
var c = cl.loadClass("groovy.lang.GroovyShell");
var shell = c.getDeclaredConstructor().newInstance();
c.getMethod("evaluate", String.class).invoke(shell, script);
Another way is to use a ProcessBuilder but that is much more involved for my
current use case.
Regards,
Per
From: Per Nyfelt <[email protected]>
Organisation: Alipsa HB
Reply to: "[email protected]" <[email protected]>
Date: Monday, 28 April 2025 at 20:23
To: "[email protected]" <[email protected]>
Subject: Running ginq from a "clean" classloader
Hi,
I am experimenting with running groovy scripts in a "clean" environment i.e. in
a GroovyClassloader that does not have a parent.
Background: One of my OSS projects is an analytics IDE where i want to enable
users to run scripts that only has the dependencies of a gradle build script
and hence i need to separate the IDE classloader from the one running the
script.
However, i have run into an issue with ginq expressions that baffles me.
A complete but minimal example is here:
https://github.com/perNyfelt/groovy-issues/tree/main/NoParentCL but the issue
is basically:
The groovy script is
def numbers = [0, 1, 2]
println "Numbers are $numbers"
var result = GQ {
from n in numbers
where n > 0
select n
}
println "Ginq result is $result"
After creating the GroovyClassloader i add the following files to the
classpath: groovy-4.0.26.jar, groovy-ginq-4.0.26.jar, groovy-macro-4.0.26.jar
When is do
new GroovyShell(new GroovyClassloader()).evaluate(script)
everything works fine but if i do
new GroovyShell(new GroovyClassloader((Classloader)null).evaluate(script)
I get
Exception in thread "main" groovy.lang.MissingMethodException: No signature of
method: Script1.GQ() is applicable for argument types: (Script1$_run_closure1)
values: [Script1$_run_closure1@5cb5bb88]
Possible solutions: is(java.lang.Object), run(), run(), any(), grep(),
any(groovy.lang.Closure)
at
org.codehaus.groovy.runtime.ScriptBytecodeAdapter.unwrap(ScriptBytecodeAdapter.java:72)
at
org.codehaus.groovy.vmplugin.v8.IndyGuardsFiltersAndSignatures.unwrap(IndyGuardsFiltersAndSignatures.java:163)
at
org.codehaus.groovy.vmplugin.v8.IndyInterface.fromCache(IndyInterface.java:321)
at Script1.run(Script1.groovy:3)
at
java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
at java.base/java.lang.reflect.Method.invoke(Method.java:580)
at
org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:343)
at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:328)
at groovy.lang.MetaClassImpl.doInvokeMethod(MetaClassImpl.java:1333)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1088)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1007)
at
org.codehaus.groovy.runtime.InvokerHelper.invokePojoMethod(InvokerHelper.java:633)
at
org.codehaus.groovy.runtime.InvokerHelper.invokeMethod(InvokerHelper.java:624)
at
org.codehaus.groovy.runtime.InvokerHelper$1.run(InvokerHelper.java:461)
at groovy.lang.GroovyShell.evaluate(GroovyShell.java:460)
at groovy.lang.GroovyShell.evaluate(GroovyShell.java:495)
at groovy.lang.GroovyShell.evaluate(GroovyShell.java:469)
at RunScript.runScript(RunScript.java:37)
at RunScript.main(RunScript.java:18)
Does anyone know why that would be the case and/or a possible workaround?
Regards,
Per
