IAE: object is not an instance of declaring class when loading some Gradle projects

[lkishalmi]

Apache NetBeans version

Apache NetBeans 15 release candidate

What happened

Just opened and closed some project groups when I got the following exception:

java.lang.IllegalArgumentException: object is not an instance of declaring class
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:568)
	at org.netbeans.modules.gradle.loaders.LegacyProjectLoader.getLocation(LegacyProjectLoader.java:332)
	at org.netbeans.modules.gradle.loaders.LegacyProjectLoader.createReport(LegacyProjectLoader.java:375)
	at org.netbeans.modules.gradle.loaders.LegacyProjectLoader.exceptionsToProblems(LegacyProjectLoader.java:314)
	at org.netbeans.modules.gradle.loaders.LegacyProjectLoader.loadGradleProject(LegacyProjectLoader.java:243)
	at org.netbeans.modules.gradle.loaders.LegacyProjectLoader.access$200(LegacyProjectLoader.java:89)
[catch] at org.netbeans.modules.gradle.loaders.LegacyProjectLoader$ProjectLoaderTask.call(LegacyProjectLoader.java:574)
	at org.netbeans.modules.gradle.loaders.LegacyProjectLoader$ProjectLoaderTask.call(LegacyProjectLoader.java:543)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1418)
	at org.netbeans.modules.openide.util.GlobalLookup.execute(GlobalLookup.java:45)
	at org.openide.util.lookup.Lookups.executeWith(Lookups.java:278)
	at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2033)

Souldn't we do some instance checks before calling methods getLocation and getLineNumber? If that's not possible, probably we could just swallow this exception.

How to reproduce

Well, I wish I could safely reproduce this one.

Did this work correctly in an earlier version?

No / Don't know

Operating System

Ubuntu 22.04

JDK

JDK17

Apache NetBeans packaging

Apache NetBeans Snap Package

Anything else

Well, this one is not a blocker for NetBeans 15.

Are you willing to submit a pull request?

Yes

Code of Conduct

Yes