注释处理异常：分析失败：java.lang.reflect.InvocationTargetException

Question

我正在编写自己的注释处理器，我希望能够注释 return 类型的函数。

注释代码如下：

@Retention(AnnotationRetention.SOURCE)
@Target(AnnotationTarget.FUNCTION)
annotation class ReturnType(val type: KClass<*>)

注释处理器的部分代码：

annotatedElement.enclosedElements
    .filter { it.kind == ElementKind.METHOD }
    .forEach { method ->
        val returnType = method.getAnnotation(ReturnType::class.java).type
    }

当我尝试编译代码时出现以下异常：

java.lang.IllegalStateException: failed to analyze: java.lang.reflect.InvocationTargetException at org.jetbrains.kotlin.analyzer.AnalysisResult.throwIfError(AnalysisResult.kt:56) at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.compileModules$cli(KotlinToJVMBytecodeCompiler.kt:182) at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.kt:165) at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.kt:55) at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.kt:84) at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.kt:42) at org.jetbrains.kotlin.cli.common.CLITool.exec(CLITool.kt:104) at org.jetbrains.kotlin.daemon.CompileServiceImpl.compile(CompileServiceImpl.kt:1558) at jdk.internal.reflect.GeneratedMethodAccessor104.invoke(Unknown Source) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:566) at java.rmi/sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:359) at java.rmi/sun.rmi.transport.Transport.run(Transport.java:200) at java.rmi/sun.rmi.transport.Transport.run(Transport.java:197) at java.base/java.security.AccessController.doPrivileged(Native Method) at java.rmi/sun.rmi.transport.Transport.serviceCall(Transport.java:196) at java.rmi/sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:562) at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:796) at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run[=13=](TCPTransport.java:677) at java.base/java.security.AccessController.doPrivileged(Native Method) at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:676) at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) at java.base/java.lang.Thread.run(Thread.java:834) Caused by: java.lang.reflect.InvocationTargetException at jdk.internal.reflect.GeneratedMethodAccessor122.invoke(Unknown Source) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:566) at org.jetbrains.kotlin.kapt3.base.AnnotationProcessingKt.doAnnotationProcessing(annotationProcessing.kt:76) at org.jetbrains.kotlin.kapt3.base.AnnotationProcessingKt.doAnnotationProcessing$default(annotationProcessing.kt:35) at org.jetbrains.kotlin.kapt3.AbstractKapt3Extension.runAnnotationProcessing(Kapt3Extension.kt:224) at org.jetbrains.kotlin.kapt3.AbstractKapt3Extension.analysisCompleted(Kapt3Extension.kt:187) at org.jetbrains.kotlin.kapt3.ClasspathBasedKapt3Extension.analysisCompleted(Kapt3Extension.kt:98) at org.jetbrains.kotlin.cli.jvm.compiler.TopDownAnalyzerFacadeForJVM$analyzeFilesWithJavaIntegration.invoke(TopDownAnalyzerFacadeForJVM.kt:97) at org.jetbrains.kotlin.cli.jvm.compiler.TopDownAnalyzerFacadeForJVM.analyzeFilesWithJavaIntegration(TopDownAnalyzerFacadeForJVM.kt:107) at org.jetbrains.kotlin.cli.jvm.compiler.TopDownAnalyzerFacadeForJVM.analyzeFilesWithJavaIntegration$default(TopDownAnalyzerFacadeForJVM.kt:82) at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler$analyze.invoke(KotlinToJVMBytecodeCompiler.kt:557) at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler$analyze.invoke(KotlinToJVMBytecodeCompiler.kt:82) at org.jetbrains.kotlin.cli.common.messages.AnalyzerWithCompilerReport.analyzeAndReport(AnalyzerWithCompilerReport.kt:107) at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.analyze(KotlinToJVMBytecodeCompiler.kt:548) at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.compileModules$cli(KotlinToJVMBytecodeCompiler.kt:177) ... 22 more Caused by: com.sun.tools.javac.processing.AnnotationProcessingError: javax.lang.model.type.MirroredTypeException: Attempt to access Class object for TypeMirror int at jdk.compiler/com.sun.tools.javac.processing.JavacProcessingEnvironment.callProcessor(JavacProcessingEnvironment.java:992) at jdk.compiler/com.sun.tools.javac.processing.JavacProcessingEnvironment.discoverAndRunProcs(JavacProcessingEnvironment.java:896) at jdk.compiler/com.sun.tools.javac.processing.JavacProcessingEnvironment$Round.run(JavacProcessingEnvironment.java:1222) at jdk.compiler/com.sun.tools.javac.processing.JavacProcessingEnvironment.doProcessing(JavacProcessingEnvironment.java:1334) at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.processAnnotations(JavaCompiler.java:1258) at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.processAnnotations(JavaCompiler.java:1157) ... 38 more Caused by: javax.lang.model.type.MirroredTypeException: Attempt to access Class object for TypeMirror int at jdk.compiler/com.sun.tools.javac.model.AnnotationProxyMaker$MirroredTypeExceptionProxy.generateException(AnnotationProxyMaker.java:309) at java.base/sun.reflect.annotation.AnnotationInvocationHandler.invoke(AnnotationInvocationHandler.java:86) at com.sun.proxy.$Proxy48.type(Unknown Source) at annotation.CreateNoOpProcessor.generateClass(CreateNoOpProcessor.kt:64) at annotation.CreateNoOpProcessor.process(CreateNoOpProcessor.kt:43) at org.jetbrains.kotlin.kapt3.base.incremental.IncrementalProcessor.process(incrementalProcessors.kt) at org.jetbrains.kotlin.kapt3.base.ProcessorWrapper.process(annotationProcessing.kt:147) at jdk.compiler/com.sun.tools.javac.processing.JavacProcessingEnvironment.callProcessor(JavacProcessingEnvironment.java:980) ... 43 more

Answer 1

解决办法可以在下面link找到： https://area-51.blog/2009/02/13/getting-class-values-from-annotations-in-an-annotationprocessor/

诀窍是捕获 MirroredTypeException 并从中提取 typeMirror。

val returnType: TypeMirror? = try {
    method.getAnnotation(ReturnType::class.java)?.type
    null
} catch (e: MirroredTypeException) {
    e.typeMirror
}