Java9环境IntelliJ中Groovy+openCSV缺失ResultSet依赖求助

我在Java 9环境中使用Groovy 2.4搭配OpenCSV 4.0开发程序，通过Gradle的runApp任务运行时一切正常，但在IntelliJ IDEA中运行/编译时，编译器抛出错误，提示因缺失java/sql/ResultSet依赖，无法加载com.opencsv.CSVWriter类。

相关配置 #

Gradle依赖与任务配置

// https://mvnrepository.com/artifact/com.opencsv/opencsv
compile group: 'com.opencsv', name: 'opencsv', version: '4.0'
task runApp(type: JavaExec) {
    classpath = sourceSets.main.runtimeClasspath
    main = 'mongo.UserReport'
}

堆栈跟踪

Error:Groovyc: While compiling Tools_main: java.lang.RuntimeException: java.lang.NoClassDefFoundError: Unable to load class com.opencsv.CSVWriter due to missing dependency java/sql/ResultSet
at org.codehaus.groovy.control.CompilationUnit.convertUncaughtExceptionToCompilationError(CompilationUnit.java:1101)
at org.codehaus.groovy.control.CompilationUnit.applyToPrimaryClassNodes(CompilationUnit.java:1079)
at org.codehaus.groovy.control.CompilationUnit.doPhaseOperation(CompilationUnit.java:603)
at org.codehaus.groovy.control.CompilationUnit.processPhaseOperations(CompilationUnit.java:581)
at org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:558)
at org.jetbrains.groovy.compiler.rt.GroovyCompilerWrapper.compile(GroovyCompilerWrapper.java:62)
at org.jetbrains.groovy.compiler.rt.DependentGroovycRunner.runGroovyc(DependentGroovycRunner.java:115)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564)
at org.jetbrains.groovy.compiler.rt.GroovycRunner.intMain2(GroovycRunner.java:136)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564)
at org.jetbrains.jps.incremental.groovy.InProcessGroovyc.runGroovycInThisProcess(InProcessGroovyc.java:158)
at org.jetbrains.jps.incremental.groovy.InProcessGroovyc.lambda$runGroovyc$0(InProcessGroovyc.java:88)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
at java.base/java.lang.Thread.run(Thread.java:844)
Caused by: java.lang.NoClassDefFoundError: Unable to load class com.opencsv.CSVWriter due to missing dependency java/sql/ResultSet
at org.codehaus.groovy.vmplugin.v5.Java5.configureClassNode(Java5.java:397)
at org.codehaus.groovy.ast.ClassNode.lazyClassInit(ClassNode.java:280)
at org.codehaus.groovy.ast.ClassNode.getUnresolvedSuperClass(ClassNode.java:1009)
at org.codehaus.groovy.ast.ClassNode.getUnresolvedSuperClass(ClassNode.java:1004)
at org.codehaus.groovy.ast.ClassNode.getSuperClass(ClassNode.java:998)
at org.codehaus.groovy.ast.ClassNode.isDerivedFrom(ClassNode.java:941)
at org.codehaus.groovy.classgen.asm.InvocationWriter.castToNonPrimitiveIfNecessary(InvocationWriter.java:863)
at org.codehaus.groovy.classgen.asm.OperandStack.doConvertAndCast(OperandStack.java:345)
at org.codehaus.groovy.classgen.asm.OperandStack.doGroovyCast(OperandStack.java:282)
at org.codehaus.groovy.classgen.asm.BinaryExpressionHelper.evaluateEqual(BinaryExpressionHelper.java:344)
at org.codehaus.groovy.classgen.AsmClassGenerator.visitDeclarationExpression(AsmClassGenerator.java:664)
at org.codehaus.groovy.ast.expr.DeclarationExpression.visit(DeclarationExpression.java:89)
at org.codehaus.groovy.classgen.asm.StatementWriter.writeExpressionStatement(StatementWriter.java:613)
at org.codehaus.groovy.classgen.asm.OptimizingStatementWriter.writeExpressionStatement(OptimizingStatementWriter.java:366)
at org.codehaus.groovy.classgen.AsmClassGenerator.visitExpressionStatement(AsmClassGenerator.java:651)
at org.codehaus.groovy.ast.stmt.ExpressionStatement.visit(ExpressionStatement.java:42)
at org.codehaus.groovy.classgen.asm.StatementWriter.writeBlockStatement(StatementWriter.java:85)
at org.codehaus.groovy.classgen.asm.OptimizingStatementWriter.writeBlockStatement(OptimizingStatementWriter.java:159)
at org.codehaus.groovy.classgen.AsmClassGenerator.visitBlockStatement(AsmClassGenerator.java:597)
at org.codehaus.groovy.ast.stmt.BlockStatement.visit(BlockStatement.java:71)
at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitClassCodeContainer(ClassCodeVisitorSupport.java:104)
at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitConstructorOrMethod(ClassCodeVisitorSupport.java:115)
at org.codehaus.groovy.classgen.AsmClassGenerator.visitStdMethod(AsmClassGenerator.java:461)
at org.codehaus.groovy.classgen.AsmClassGenerator.visitConstructorOrMethod(AsmClassGenerator.java:414)
at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitMethod(ClassCodeVisitorSupport.java:126)
at org.codehaus.groovy.classgen.AsmClassGenerator.visitMethod(AsmClassGenerator.java:538)
at org.codehaus.groovy.ast.ClassNode.visitContents(ClassNode.java:1081)
at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitClass(ClassCodeVisitorSupport.java:53)
at org.codehaus.groovy.classgen.AsmClassGenerator.visitClass(AsmClassGenerator.java:260)
at org.codehaus.groovy.control.CompilationUnit$17.call(CompilationUnit.java:825)
at org.codehaus.groovy.control.CompilationUnit.applyToPrimaryClassNodes(CompilationUnit.java:1065)

这个问题我之前碰到过，本质是Java 9的**模块化系统（JPMS）**和Groovy 2.4编译器在IntelliJ环境下的兼容性问题：Java 9开始，java.sql模块不再默认被自动引入，而Groovy 2.4的编译器在IntelliJ里没有自动处理这个依赖，导致编译时找不到java.sql.ResultSet——而OpenCSV 4.0的CSVWriter刚好依赖这个类。至于Gradle任务能正常运行，是因为JavaExec用的是传统类路径模式，不会受模块化的严格限制，和IDE的编译逻辑不一样。

下面给你两种靠谱的解决方法：

方法一：通过Gradle全局配置解决 #

修改你的Gradle构建脚本，给Groovy编译任务添加--add-modules java.sql参数，强制编译器引入该模块：

compileGroovy {
    options.compilerArgs += ['--add-modules', 'java.sql']
}

// 如果有测试代码，也要同步配置
compileTestGroovy {
    options.compilerArgs += ['--add-modules', 'java.sql']
}

配置完成后，执行gradle clean build，然后回到IntelliJ点击Gradle工具栏的刷新按钮同步项目，重新编译就没问题了。

方法二：直接在IntelliJ中配置编译器参数 #

如果你不想修改Gradle脚本，也可以直接在IDE里设置：

1. 打开File > Settings > Build, Execution, Deployment > Compiler > Groovy Compiler（Mac用户是IntelliJ IDEA > Settings）
2. 在Additional command line parameters输入框中填入：--add-modules java.sql
3. 点击Apply和OK，然后重启编译即可

内容的提问来源于stack exchange，提问作者sfgroups