I received the nullability warning,
/Users/ben/projects/caffeine/caffeine/src/test/java/com/github/benmanes/caffeine/cache/testing/CacheSpec.java:431: warning: [NullAway] returning @Nullable expression from method with @NonNull return type
return null;
^
(see http://t.uber.com/nullaway )
Did you mean '@SuppressWarnings("NullAway") @Override public Int load(Int key) {'?and I tried to fix it by adding the @Nullable to the generic type and method to match the interface.
/** The {@link CacheLoader} for constructing the {@link LoadingCache}. */
enum Loader implements CacheLoader<Int, @Nullable Int> {
/** A flag indicating that a loader should not be configured. */
DISABLED {
@Override public Int load(Int key) {
throw new AssertionError();
}
},
/** A loader that always returns null (no mapping). */
NULL {
@Override public @Nullable Int load(Int key) {
return null;
}
},
...When adding it to the interface type, the compilation failed due targetTypeMatches throwing an assertion.
Details
> Task :caffeine:compileTestJava FAILED
/Users/ben/projects/caffeine/caffeine/src/test/java/com/github/benmanes/caffeine/cache/testing/CacheSpec.java:421: error: An unhandled exception was thrown by the Error Prone static analysis plugin.
enum Loader implements CacheLoader<Int, @Nullable Int> {
^
Please report this at https://github.com/google/error-prone/issues/new and include the following:
error-prone version: 2.36.0
BugPattern: NullAway
Stack Trace:
java.lang.AssertionError: unsupported element kind ENUM symbol com.github.benmanes.caffeine.cache.testing.CacheSpec.Loader
at com.uber.nullaway.NullabilityUtil.targetTypeMatches(NullabilityUtil.java:379)
at com.uber.nullaway.NullabilityUtil.lambda$getTypeUseAnnotations$3(NullabilityUtil.java:337)
at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:178)
at java.base/java.util.Spliterators$IteratorSpliterator.tryAdvance(Spliterators.java:1950)
at java.base/java.util.stream.StreamSpliterators$WrappingSpliterator.lambda$initPartialTraversalState$0(StreamSpliterators.java:292)
at java.base/java.util.stream.StreamSpliterators$AbstractWrappingSpliterator.fillBuffer(StreamSpliterators.java:206)
at java.base/java.util.stream.StreamSpliterators$AbstractWrappingSpliterator.doAdvance(StreamSpliterators.java:161)
at java.base/java.util.stream.StreamSpliterators$WrappingSpliterator.tryAdvance(StreamSpliterators.java:298)
at java.base/java.util.stream.Streams$ConcatSpliterator.tryAdvance(Streams.java:723)
at java.base/java.util.stream.ReferencePipeline.forEachWithCancel(ReferencePipeline.java:129)
at java.base/java.util.stream.AbstractPipeline.copyIntoWithCancel(AbstractPipeline.java:527)
at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:513)
at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499)
at java.base/java.util.stream.MatchOps$MatchOp.evaluateSequential(MatchOps.java:230)
at java.base/java.util.stream.MatchOps$MatchOp.evaluateSequential(MatchOps.java:196)
at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.base/java.util.stream.ReferencePipeline.anyMatch(ReferencePipeline.java:632)
at com.uber.nullaway.NullAway.symbolHasExternalInitAnnotation(NullAway.java:2172)
at com.uber.nullaway.NullAway.checkConstructorInitialization(NullAway.java:2146)
at com.uber.nullaway.NullAway.checkFieldInitialization(NullAway.java:2014)
at com.uber.nullaway.NullAway.matchClass(NullAway.java:1659)
at com.google.errorprone.scanner.ErrorProneScanner.processMatchers(ErrorProneScanner.java:509)
at com.google.errorprone.scanner.ErrorProneScanner.visitClass(ErrorProneScanner.java:618)
at com.google.errorprone.scanner.ErrorProneScanner.visitClass(ErrorProneScanner.java:170)
at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCClassDecl.accept(JCTree.java:855)
at jdk.compiler/com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:92)
at com.google.errorprone.scanner.Scanner.scan(Scanner.java:74)
at com.google.errorprone.scanner.Scanner.scan(Scanner.java:48)
at jdk.compiler/com.sun.source.util.TreeScanner.scanAndReduce(TreeScanner.java:96)
at jdk.compiler/com.sun.source.util.TreeScanner.scan(TreeScanner.java:111)
at jdk.compiler/com.sun.source.util.TreeScanner.scanAndReduce(TreeScanner.java:119)
at jdk.compiler/com.sun.source.util.TreeScanner.visitClass(TreeScanner.java:203)
at com.google.errorprone.scanner.ErrorProneScanner.visitClass(ErrorProneScanner.java:619)
at com.google.errorprone.scanner.ErrorProneScanner.visitClass(ErrorProneScanner.java:170)
at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCClassDecl.accept(JCTree.java:855)
at jdk.compiler/com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:92)
at com.google.errorprone.scanner.Scanner.scan(Scanner.java:74)
at com.google.errorprone.scanner.Scanner.scan(Scanner.java:48)
at jdk.compiler/com.sun.source.util.TreeScanner.scan(TreeScanner.java:111)
at jdk.compiler/com.sun.source.util.TreeScanner.scanAndReduce(TreeScanner.java:119)
at jdk.compiler/com.sun.source.util.TreeScanner.visitCompilationUnit(TreeScanner.java:152)
at com.google.errorprone.scanner.ErrorProneScanner.visitCompilationUnit(ErrorProneScanner.java:631)
at com.google.errorprone.scanner.ErrorProneScanner.visitCompilationUnit(ErrorProneScanner.java:170)
at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCCompilationUnit.accept(JCTree.java:623)
at jdk.compiler/com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:66)
at com.google.errorprone.scanner.Scanner.scan(Scanner.java:58)
at com.google.errorprone.scanner.ErrorProneScannerTransformer.apply(ErrorProneScannerTransformer.java:43)
at com.google.errorprone.ErrorProneAnalyzer.finished(ErrorProneAnalyzer.java:227)
at jdk.compiler/com.sun.tools.javac.api.MultiTaskListener.finished(MultiTaskListener.java:133)
at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.flow(JavaCompiler.java:1435)
at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.flow(JavaCompiler.java:1382)
at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:965)
at jdk.compiler/com.sun.tools.javac.api.JavacTaskImpl.lambda$doCall$0(JavacTaskImpl.java:104)
at jdk.compiler/com.sun.tools.javac.api.JavacTaskImpl.invocationHelper(JavacTaskImpl.java:152)
at jdk.compiler/com.sun.tools.javac.api.JavacTaskImpl.doCall(JavacTaskImpl.java:100)
at jdk.compiler/com.sun.tools.javac.api.JavacTaskImpl.call(JavacTaskImpl.java:94)
at org.gradle.internal.compiler.java.IncrementalCompileTask.call(IncrementalCompileTask.java:92)
at org.gradle.api.internal.tasks.compile.AnnotationProcessingCompileTask.call(AnnotationProcessingCompileTask.java:94)
at org.gradle.api.internal.tasks.compile.ResourceCleaningCompilationTask.call(ResourceCleaningCompilationTask.java:57)
at org.gradle.api.internal.tasks.compile.JdkJavaCompiler.execute(JdkJavaCompiler.java:78)
at org.gradle.api.internal.tasks.compile.JdkJavaCompiler.execute(JdkJavaCompiler.java:46)
at org.gradle.api.internal.tasks.compile.daemon.AbstractIsolatedCompilerWorkerExecutor$CompilerWorkAction.execute(AbstractIsolatedCompilerWorkerExecutor.java:78)
at org.gradle.workers.internal.DefaultWorkerServer.execute(DefaultWorkerServer.java:63)
at org.gradle.workers.internal.AbstractClassLoaderWorker$1.create(AbstractClassLoaderWorker.java:54)
at org.gradle.workers.internal.AbstractClassLoaderWorker$1.create(AbstractClassLoaderWorker.java:48)
at org.gradle.internal.classloader.ClassLoaderUtils.executeInClassloader(ClassLoaderUtils.java:100)
at org.gradle.workers.internal.AbstractClassLoaderWorker.executeInClassLoader(AbstractClassLoaderWorker.java:48)
at org.gradle.workers.internal.FlatClassLoaderWorker.run(FlatClassLoaderWorker.java:32)
at org.gradle.workers.internal.FlatClassLoaderWorker.run(FlatClassLoaderWorker.java:22)
at org.gradle.workers.internal.WorkerDaemonServer.run(WorkerDaemonServer.java:109)
at org.gradle.workers.internal.WorkerDaemonServer.run(WorkerDaemonServer.java:78)
at org.gradle.process.internal.worker.request.WorkerAction$1.call(WorkerAction.java:159)
at org.gradle.process.internal.worker.child.WorkerLogEventListener.withWorkerLoggingProtocol(WorkerLogEventListener.java:41)
at org.gradle.process.internal.worker.request.WorkerAction.lambda$run$1(WorkerAction.java:156)
at org.gradle.internal.operations.CurrentBuildOperationRef.with(CurrentBuildOperationRef.java:85)
at org.gradle.process.internal.worker.request.WorkerAction.run(WorkerAction.java:148)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
at java.base/java.lang.reflect.Method.invoke(Method.java:580)
at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
at org.gradle.internal.remote.internal.hub.MessageHubBackedObjectConnection$DispatchWrapper.dispatch(MessageHubBackedObjectConnection.java:182)
at org.gradle.internal.remote.internal.hub.MessageHubBackedObjectConnection$DispatchWrapper.dispatch(MessageHubBackedObjectConnection.java:164)
at org.gradle.internal.remote.internal.hub.MessageHub$Handler.run(MessageHub.java:414)
at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:64)
at org.gradle.internal.concurrent.AbstractManagedExecutor$1.run(AbstractManagedExecutor.java:48)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642)
at java.base/java.lang.Thread.run(Thread.java:1583)
1 error
I received the nullability warning,
and I tried to fix it by adding the
@Nullableto the generic type and method to match the interface.When adding it to the interface type, the compilation failed due
targetTypeMatchesthrowing an assertion.Details