Partial jdk classes cannot be resolved. It is indirectly reference from required ...

1. Open spring-petclinic project in VS Code and observe the compilation error below.

[{
	"resource": "/C:/Work/Code/spring-petclinic/src/test/java/org/springframework/samples/petclinic/PetClinicIntegrationTests.java",
	"owner": "_generated_diagnostic_collection_name_#4",
	"code": "16777563",
	"severity": 8,
	"message": "The type java.lang.Enum cannot be resolved. It is indirectly referenced from required type org.springframework.boot.test.context.SpringBootTest.WebEnvironment",
	"source": "Java",
	"startLineNumber": 1,
	"startColumn": 1,
	"endLineNumber": 1,
	"endColumn": 2
}]

2. In the Java Projects view, Enum.class is also not resolved in the JRE tree view.

3. Click Enum.class in the JRE tree view, Java extension reports error as below.

!ENTRY org.eclipse.jdt.ls.core 4 0 2023-10-26 16:12:15.657
!MESSAGE Enum.class [in java.lang [in <module:java.base>]] does not exist
!STACK 1
Java Model Exception: Error in Java Model (code 969): Enum.class [in java.lang [in <module:java.base>]] does not exist
	at org.eclipse.jdt.internal.core.JavaElement.newNotPresentException(JavaElement.java:550)
	at org.eclipse.jdt.internal.core.ClassFile.getBinaryTypeInfo(ClassFile.java:203)
	at org.eclipse.jdt.internal.core.ClassFile.buildStructure(ClassFile.java:92)
	at org.eclipse.jdt.internal.core.Openable.generateInfos(Openable.java:266)
	at org.eclipse.jdt.internal.core.JavaElement.openWhenClosed(JavaElement.java:573)
	at org.eclipse.jdt.internal.core.JavaElement.getElementInfo(JavaElement.java:304)
	at org.eclipse.jdt.internal.core.JavaElement.getElementInfo(JavaElement.java:290)
	at org.eclipse.jdt.internal.core.Openable.getBuffer(Openable.java:296)
	at org.eclipse.jdt.internal.core.AbstractClassFile.getBuffer(AbstractClassFile.java:245)
	at org.eclipse.jdt.internal.core.AbstractClassFile.getSourceRange(AbstractClassFile.java:371)
	at org.eclipse.jdt.ls.core.internal.JDTUtils.resolveTypeRoot(JDTUtils.java:452)
	at org.eclipse.jdt.ls.core.internal.handlers.FoldingRangeHandler.foldingRange(FoldingRangeHandler.java:66)
	at org.eclipse.jdt.ls.core.internal.handlers.JDTLanguageServer.lambda$30(JDTLanguageServer.java:1027)
	at org.eclipse.jdt.ls.core.internal.handlers.JDTLanguageServer.lambda$59(JDTLanguageServer.java:1216)
	at java.base/java.util.concurrent.CompletableFuture$UniApply.tryFire(Unknown Source)
	at java.base/java.util.concurrent.CompletableFuture$Completion.exec(Unknown Source)
	at java.base/java.util.concurrent.ForkJoinTask.doExec(Unknown Source)
	at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(Unknown Source)
	at java.base/java.util.concurrent.ForkJoinPool.scan(Unknown Source)
	at java.base/java.util.concurrent.ForkJoinPool.runWorker(Unknown Source)
	at java.base/java.util.concurrent.ForkJoinWorkerThread.run(Unknown Source)
!SUBENTRY 1 org.eclipse.jdt.core 4 969 2023-10-26 16:12:15.657
!MESSAGE Enum.class [in java.lang [in <module:java.base>]] does not exist

4. I cannot reproduce this issue consistently, but I encountered it twice in my local environment recently. Reloading the window usually fixes it. I am opening this issue to see if anyone else has the same problem.

在 spring-petclinic 项目中重现该问题，并结合 Java Projects JRE 树检查 PetClinicIntegrationTests.java 的诊断信息。先从缺少 Enum.class 的报告和 org.eclipse.jdt.ls.core 的堆栈跟踪入手，然后比较重新加载 VS Code 窗口前后的行为。当不完整的 JDK 类不再产生所报告的解析错误时，即表示完成。