Upgrade to Java8 failing for jasper grails plugin

Question

I want to upgrade my grails server to use Java 8 instead of 7. When I upgrade, I encounter the exception shown below. Other people who have reported similar errors have said that the problem can be fixed by changing the Java version of the IDE, but that doesn't seem to apply here because I get the exception if I run grails from the command line or from Intellij. Other people have reported upgrading tomcat would help, so I'm on the latest from version 7.

My java home is set to Java 8, I've changed the source/target of the compiler to 1.8 to make sure nothing is creeping in. I've cleared all the .class files, refreshed-dependencies, clean-all, rm .slcache, etc and nothing seems to affect this.

BuildConfig.groovy:        compile ":jasper:1.11.0"
BuildConfig.groovy:        build ":tomcat:7.0.70"
BuildConfig.groovy:grails.project.target.level = 1.8
BuildConfig.groovy:grails.project.source.level = 1.8

Note, this plugin is using Jasperreports 5.6.1. I've been unable to determine from TIBCO's website whether their .jars should or should not be able to support Java 8. Also, I'm using grails 2.5.5 and I'm on OSX.

2016-12-05 12:51:56,060 [http-bio-8091-exec-5] ERROR design.JRJdtCompiler  - Compilation error
org.eclipse.jdt.internal.compiler.classfmt.ClassFormatException
    at org.eclipse.jdt.internal.compiler.classfmt.ClassFileReader.<init>(ClassFileReader.java:372)
    at net.sf.jasperreports.engine.design.JRJdtCompiler$1.findType(JRJdtCompiler.java:255)
    at net.sf.jasperreports.engine.design.JRJdtCompiler$1.findType(JRJdtCompiler.java:192)
    at org.eclipse.jdt.internal.compiler.lookup.LookupEnvironment.askForType(LookupEnvironment.java:113)
    at org.eclipse.jdt.internal.compiler.lookup.UnresolvedReferenceBinding.resolve(UnresolvedReferenceBinding.java:49)
    at org.eclipse.jdt.internal.compiler.lookup.BinaryTypeBinding.resolveType(BinaryTypeBinding.java:122)
    at org.eclipse.jdt.internal.compiler.lookup.LookupEnvironment.getTypeFromTypeSignature(LookupEnvironment.java:1335)
    at org.eclipse.jdt.internal.compiler.lookup.LookupEnvironment.getTypeFromVariantTypeSignature(LookupEnvironment.java:1391)
    at org.eclipse.jdt.internal.compiler.lookup.LookupEnvironment.getTypeArgumentsFromSignature(LookupEnvironment.java:1172)
    at org.eclipse.jdt.internal.compiler.lookup.LookupEnvironment.getTypeFromTypeSignature(LookupEnvironment.java:1340)
    at org.eclipse.jdt.internal.compiler.lookup.BinaryTypeBinding.createMethod(BinaryTypeBinding.java:550)
    at org.eclipse.jdt.internal.compiler.lookup.BinaryTypeBinding.createMethods(BinaryTypeBinding.java:630)
    at org.eclipse.jdt.internal.compiler.lookup.BinaryTypeBinding.cachePartsFrom(BinaryTypeBinding.java:365)
    at org.eclipse.jdt.internal.compiler.lookup.LookupEnvironment.createBinaryTypeFrom(LookupEnvironment.java:688)
    at org.eclipse.jdt.internal.compiler.lookup.LookupEnvironment.createBinaryTypeFrom(LookupEnvironment.java:667)
    at org.eclipse.jdt.internal.compiler.Compiler.accept(Compiler.java:296)
    at org.eclipse.jdt.internal.compiler.lookup.LookupEnvironment.askForType(LookupEnvironment.java:118)
    at org.eclipse.jdt.internal.compiler.lookup.UnresolvedReferenceBinding.resolve(UnresolvedReferenceBinding.java:49)
    at org.eclipse.jdt.internal.compiler.lookup.BinaryTypeBinding.resolveType(BinaryTypeBinding.java:122)
    at org.eclipse.jdt.internal.compiler.lookup.PackageBinding.getType(PackageBinding.java:137)
    at org.eclipse.jdt.internal.compiler.lookup.Scope.findType(Scope.java:1611)
    at org.eclipse.jdt.internal.compiler.lookup.Scope.getTypeOrPackage(Scope.java:2708)
    at org.eclipse.jdt.internal.compiler.lookup.Scope.getType(Scope.java:2405)
    at org.eclipse.jdt.internal.compiler.ast.SingleTypeReference.getTypeBinding(SingleTypeReference.java:44)
    at org.eclipse.jdt.internal.compiler.ast.TypeReference.internalResolveType(TypeReference.java:132)
    at org.eclipse.jdt.internal.compiler.ast.TypeReference.resolveType(TypeReference.java:204)
    at org.eclipse.jdt.internal.compiler.lookup.SourceTypeBinding.resolveTypesFor(SourceTypeBinding.java:1477)
    at org.eclipse.jdt.internal.compiler.lookup.SourceTypeBinding.methods(SourceTypeBinding.java:1175)
    at org.eclipse.jdt.internal.compiler.lookup.SourceTypeBinding.faultInTypesForFieldsAndMethods(SourceTypeBinding.java:678)
    at org.eclipse.jdt.internal.compiler.lookup.CompilationUnitScope.faultInTypes(CompilationUnitScope.java:469)
    at org.eclipse.jdt.internal.compiler.Compiler.process(Compiler.java:756)
    at org.eclipse.jdt.internal.compiler.Compiler.compile(Compiler.java:468)
    at net.sf.jasperreports.engine.design.JRJdtCompiler.compileUnits(JRJdtCompiler.java:167)
    at net.sf.jasperreports.engine.design.JRAbstractCompiler.compileReport(JRAbstractCompiler.java:201)
    at net.sf.jasperreports.engine.JasperCompileManager.compile(JasperCompileManager.java:354)
    at net.sf.jasperreports.engine.JasperCompileManager.compileReport(JasperCompileManager.java:614)
    at gdbxt.JasperReportJavaService.$tt__compileReport(JasperReportJavaService.groovy:31)
    at gdbxt.ProteinPurificationBatchController$$EQ4X8VQ0.createReport(ProteinPurificationBatchController.groovy:102)
    at grails.plugin.cache.web.filter.PageFragmentCachingFilter.doFilter(PageFragmentCachingFilter.java:198)
    at grails.plugin.cache.web.filter.AbstractFilter.doFilter(AbstractFilter.java:63)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
Error 
|
net.sf.jasperreports.engine.JRException: Errors were encountered when compiling report expressions class file:
1. The type java.util.Map$Entry cannot be resolved. It is indirectly referenced from required .class files
/*
^
1 errors

Error |
    at net.sf.jasperreports.engine.design.JRAbstractCompiler.compileReport(JRAbstractCompiler.java:204)
Error |
    at net.sf.jasperreports.engine.JasperCompileManager.compile(JasperCompileManager.java:354)
Error |
    at net.sf.jasperreports.engine.JasperCompileManager.compileReport(JasperCompileManager.java:614)
Error |
    at net.sf.jasperreports.engine.JasperCompileManager$compileReport.call(Unknown Source)
Error |
    at gdbxt.JasperReportJavaService.$tt__compileReport(JasperReportJavaService.groovy:31)

Answer 1

Even though I'd seen other people post that a more recent version of Tomcat 7 would work, it looks like updating to Tomcat 8 did the trick for me.

BuildConfig.groovy:        build ":tomcat:8.0.33"

Before trying tomcat 7.0.70 I had been trying tomcat 7.0.55. If tomcat 7.0.70 should have worked and 7.0.55 doesn't, then perhaps the problem was some old 7.0.55 jar was being picked up by 7.0.70.