#1138 Anonymous inner class in enum causes NPE

[Nathan Toone]

When analyzing an enum that contains an anonymous inner class, a NullPointerException is thrown:

Error while processing file
java.lang.NullPointerException
    at net.sourceforge.pmd.lang.java.typeresolution.ClassTypeResolver.visit(ClassTypeResolver.java:191)
    at net.sourceforge.pmd.lang.java.ast.ASTClassOrInterfaceType.jjtAccept(ASTClassOrInterfaceType.java:19)
    at net.sourceforge.pmd.lang.java.ast.AbstractJavaNode.childrenAccept(AbstractJavaNode.java:52)
    at net.sourceforge.pmd.lang.java.ast.JavaParserVisitorAdapter.visit(JavaParserVisitorAdapter.java:6)
    at net.sourceforge.pmd.lang.java.ast.JavaParserVisitorAdapter.visit(JavaParserVisitorAdapter.java:338)
    at net.sourceforge.pmd.lang.java.typeresolution.ClassTypeResolver.visit(ClassTypeResolver.java:513)
    at net.sourceforge.pmd.lang.java.ast.ASTAllocationExpression.jjtAccept(ASTAllocationExpression.java:19)
    at net.sourceforge.pmd.lang.java.ast.AbstractJavaNode.childrenAccept(AbstractJavaNode.java:52)
    at net.sourceforge.pmd.lang.java.ast.JavaParserVisitorAdapter.visit(JavaParserVisitorAdapter.java:6)
    at net.sourceforge.pmd.lang.java.ast.JavaParserVisitorAdapter.visit(JavaParserVisitorAdapter.java:310)
    at net.sourceforge.pmd.lang.java.typeresolution.ClassTypeResolver.visit(ClassTypeResolver.java:440)
    at net.sourceforge.pmd.lang.java.ast.ASTPrimaryPrefix.jjtAccept(ASTPrimaryPrefix.java:37)
    at net.sourceforge.pmd.lang.java.ast.AbstractJavaNode.childrenAccept(AbstractJavaNode.java:52)
    at net.sourceforge.pmd.lang.java.ast.JavaParserVisitorAdapter.visit(JavaParserVisitorAdapter.java:6)
    at net.sourceforge.pmd.lang.java.ast.JavaParserVisitorAdapter.visit(JavaParserVisitorAdapter.java:306)
    at net.sourceforge.pmd.lang.java.typeresolution.ClassTypeResolver.visit(ClassTypeResolver.java:429)
    at net.sourceforge.pmd.lang.java.ast.ASTPrimaryExpression.jjtAccept(ASTPrimaryExpression.java:19)
    at net.sourceforge.pmd.lang.java.ast.AbstractJavaNode.childrenAccept(AbstractJavaNode.java:52)
    at net.sourceforge.pmd.lang.java.ast.JavaParserVisitorAdapter.visit(JavaParserVisitorAdapter.java:6)
    at net.sourceforge.pmd.lang.java.ast.JavaParserVisitorAdapter.visit(JavaParserVisitorAdapter.java:226)
    at net.sourceforge.pmd.lang.java.typeresolution.ClassTypeResolver.visit(ClassTypeResolver.java:292)
    at net.sourceforge.pmd.lang.java.ast.ASTExpression.jjtAccept(ASTExpression.java:19)
    at net.sourceforge.pmd.lang.java.ast.AbstractJavaNode.childrenAccept(AbstractJavaNode.java:52)
    at net.sourceforge.pmd.lang.java.ast.JavaParserVisitorAdapter.visit(JavaParserVisitorAdapter.java:6)
    at net.sourceforge.pmd.lang.java.ast.JavaParserVisitorAdapter.visit(JavaParserVisitorAdapter.java:170)
    at net.sourceforge.pmd.lang.java.ast.ASTVariableInitializer.jjtAccept(ASTVariableInitializer.java:19)
    at net.sourceforge.pmd.lang.java.ast.AbstractJavaNode.childrenAccept(AbstractJavaNode.java:52)
    at net.sourceforge.pmd.lang.java.ast.JavaParserVisitorAdapter.visit(JavaParserVisitorAdapter.java:6)
    at net.sourceforge.pmd.lang.java.ast.JavaParserVisitorAdapter.visit(JavaParserVisitorAdapter.java:162)
    at net.sourceforge.pmd.lang.java.typeresolution.ClassTypeResolver.visit(ClassTypeResolver.java:252)
    at net.sourceforge.pmd.lang.java.ast.ASTVariableDeclarator.jjtAccept(ASTVariableDeclarator.java:19)
    at net.sourceforge.pmd.lang.java.ast.AbstractJavaNode.childrenAccept(AbstractJavaNode.java:52)
    at net.sourceforge.pmd.lang.java.ast.JavaParserVisitorAdapter.visit(JavaParserVisitorAdapter.java:6)
    at net.sourceforge.pmd.lang.java.ast.JavaParserVisitorAdapter.visit(JavaParserVisitorAdapter.java:158)
    at net.sourceforge.pmd.lang.java.typeresolution.ClassTypeResolver.visit(ClassTypeResolver.java:245)
    at net.sourceforge.pmd.lang.java.ast.ASTFieldDeclaration.jjtAccept(ASTFieldDeclaration.java:20)
    at net.sourceforge.pmd.lang.java.ast.AbstractJavaNode.childrenAccept(AbstractJavaNode.java:52)
    at net.sourceforge.pmd.lang.java.ast.JavaParserVisitorAdapter.visit(JavaParserVisitorAdapter.java:6)
    at net.sourceforge.pmd.lang.java.ast.JavaParserVisitorAdapter.visit(JavaParserVisitorAdapter.java:43)
    at net.sourceforge.pmd.lang.java.ast.ASTClassOrInterfaceBodyDeclaration.jjtAccept(ASTClassOrInterfaceBodyDeclaration.java:38)
    at net.sourceforge.pmd.lang.java.ast.AbstractJavaNode.childrenAccept(AbstractJavaNode.java:52)
    at net.sourceforge.pmd.lang.java.ast.JavaParserVisitorAdapter.visit(JavaParserVisitorAdapter.java:6)
    at net.sourceforge.pmd.lang.java.ast.JavaParserVisitorAdapter.visit(JavaParserVisitorAdapter.java:47)
    at net.sourceforge.pmd.lang.java.ast.ASTEnumBody.jjtAccept(ASTEnumBody.java:19)
    at net.sourceforge.pmd.lang.java.ast.AbstractJavaNode.childrenAccept(AbstractJavaNode.java:52)
    at net.sourceforge.pmd.lang.java.ast.JavaParserVisitorAdapter.visit(JavaParserVisitorAdapter.java:6)
    at net.sourceforge.pmd.lang.java.ast.JavaParserVisitorAdapter.visit(JavaParserVisitorAdapter.java:138)
    at net.sourceforge.pmd.lang.java.typeresolution.ClassTypeResolver.visit(ClassTypeResolver.java:206)
    at net.sourceforge.pmd.lang.java.ast.ASTEnumDeclaration.jjtAccept(ASTEnumDeclaration.java:15)
    at net.sourceforge.pmd.lang.java.ast.AbstractJavaNode.childrenAccept(AbstractJavaNode.java:52)
    at net.sourceforge.pmd.lang.java.ast.JavaParserVisitorAdapter.visit(JavaParserVisitorAdapter.java:6)
    at net.sourceforge.pmd.lang.java.ast.JavaParserVisitorAdapter.visit(JavaParserVisitorAdapter.java:154)
    at net.sourceforge.pmd.lang.java.typeresolution.ClassTypeResolver.visit(ClassTypeResolver.java:181)
    at net.sourceforge.pmd.lang.java.ast.ASTTypeDeclaration.jjtAccept(ASTTypeDeclaration.java:33)
    at net.sourceforge.pmd.lang.java.ast.AbstractJavaNode.childrenAccept(AbstractJavaNode.java:52)
    at net.sourceforge.pmd.lang.java.ast.JavaParserVisitorAdapter.visit(JavaParserVisitorAdapter.java:6)
    at net.sourceforge.pmd.lang.java.ast.JavaParserVisitorAdapter.visit(JavaParserVisitorAdapter.java:134)
    at net.sourceforge.pmd.lang.java.typeresolution.ClassTypeResolver.visit(ClassTypeResolver.java:161)
    at net.sourceforge.pmd.lang.java.ast.ASTCompilationUnit.jjtAccept(ASTCompilationUnit.java:39)
    at net.sourceforge.pmd.lang.java.typeresolution.TypeResolutionFacade.initializeWith(TypeResolutionFacade.java:17)
    at net.sourceforge.pmd.lang.java.AbstractJavaHandler$4.start(AbstractJavaHandler.java:78)
    at net.sourceforge.pmd.SourceCodeProcessor.usesTypeResolution(SourceCodeProcessor.java:125)
    at net.sourceforge.pmd.SourceCodeProcessor.processSource(SourceCodeProcessor.java:140)
    at net.sourceforge.pmd.SourceCodeProcessor.processSourceCode(SourceCodeProcessor.java:75)
    at net.sourceforge.pmd.SourceCodeProcessor.processSourceCode(SourceCodeProcessor.java:42)
    at net.sourceforge.pmd.processor.PmdRunnable.call(PmdRunnable.java:75)
    at net.sourceforge.pmd.processor.PmdRunnable.call(PmdRunnable.java:22)
    at java.util.concurrent.FutureTask.run(FutureTask.java:262)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:724)

The same anonymous inner class defined within a class does not fail. See attached test cases PMDFail.java (which is an enum), and PMDWork.java (which is a class). I was getting the NPE just running with the basic rulesets (I actually get the NPE with any ruleset specified)

This also affects version 5.0.4 - not sure how far back it goes.

[Andreas Dangel]

Thanks for this bug report. It is actually a duplicate of https://sourceforge.net/p/pmd/bugs/1106/ - hence I'm closing this one.