ClassNotFoundException: SequencedMap

[jukzi]

When having both JDK 17 and JDK 21 configured in the IDE (and jdk 21 as default JRE) and launching a test case for a BREEE 17 project (Run As..), then it it fails

WARNING: Using incubator modules: jdk.incubator.foreign, jdk.incubator.vector
java.lang.NoClassDefFoundError: java/util/SequencedMap
	at org.apache.felix.resolver.Candidates.<init>(Candidates.java:96)
	at org.apache.felix.resolver.ResolverImpl.getInitialCandidates(ResolverImpl.java:541)
	at org.apache.felix.resolver.ResolverImpl.doResolve(ResolverImpl.java:431)
	at org.apache.felix.resolver.ResolverImpl.resolve(ResolverImpl.java:420)
	at org.apache.felix.resolver.ResolverImpl.resolve(ResolverImpl.java:374)
	at org.eclipse.osgi.container.ModuleResolver$ResolveProcess.resolveRevisions(ModuleResolver.java:1084)
	at org.eclipse.osgi.container.ModuleResolver$ResolveProcess.resolveRevisionsInBatch(ModuleResolver.java:1035)
	at org.eclipse.osgi.container.ModuleResolver$ResolveProcess.resolve(ModuleResolver.java:951)
	at org.eclipse.osgi.container.ModuleResolver.resolveDelta(ModuleResolver.java:181)
	at org.eclipse.osgi.container.ModuleContainer.resolveAndApply(ModuleContainer.java:714)
	at org.eclipse.osgi.container.ModuleContainer.resolve(ModuleContainer.java:660)
	at org.eclipse.osgi.container.ModuleContainer.resolve(ModuleContainer.java:648)
	at org.eclipse.osgi.storage.Storage.checkSystemBundle(Storage.java:431)
	at org.eclipse.osgi.storage.Storage.createStorage(Storage.java:189)
	at org.eclipse.osgi.internal.framework.EquinoxContainer.<init>(EquinoxContainer.java:108)
	at org.eclipse.osgi.launch.Equinox.<init>(Equinox.java:53)
	at org.eclipse.osgi.launch.Equinox.<init>(Equinox.java:46)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.startup(EclipseStarter.java:342)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:267)
	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.eclipse.equinox.launcher.Main.invokeFramework(Main.java:651)
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:588)
	at org.eclipse.equinox.launcher.Main.run(Main.java:1459)
	at org.eclipse.equinox.launcher.Main.main(Main.java:1432)
Caused by: java.lang.ClassNotFoundException: java.util.SequencedMap
	at java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:445)
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:592)
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:525)
	... 27 more
An error has occurred. See the log file
null.

I understand it is compiled against JDK 21, but executed with JDK 17 by default

workaround: open the Launch configuration "Main" tab -> JDK 21 is automaically(!) selected:

There after "run" launches with 21 and test runs fine.

To my understanding the launchconfiguration should use JDK 21 even without using the configuration dialog

[SarikaSinha]

@jukzi
Have you tried setting this in "Execution Environments" in the Java Preferences where the compatible JREs are listed?

[jukzi]

When i set JavaSE-17 Execution Environment to JDK21, the error is gone. But that feels only like a workaround.

[SarikaSinha]

That was the only purpose of allowing to set up the preferred JRE.

[laeubi]

I understand it is compiled against JDK 21, but executed with JDK 17 by default

Given your screenshot I think this is a bug. If the JDK to compile is higher than the JDK selected by the project it must use the --target option an not use any later constructs, this Bug is probably suffering from the same behavior:

• StringConcatFactory can not be resolved eclipse.jdt.core#1842