【开发心得】从 IntelliJ 2020.3EAP #2215运行 MapStruct 时的 NPE

问题:

ava: Internal error in the mapping processor: java.lang.NullPointerException  
	at org.mapstruct.ap.internal.processor.DefaultVersionInformation.createManifestUrl(DefaultVersionInformation.java:182)  
	at org.mapstruct.ap.internal.processor.DefaultVersionInformation.openManifest(DefaultVersionInformation.java:153)  
	at org.mapstruct.ap.internal.processor.DefaultVersionInformation.getLibraryName(DefaultVersionInformation.java:129)  
	at org.mapstruct.ap.internal.processor.DefaultVersionInformation.getCompiler(DefaultVersionInformation.java:122)  
	at org.mapstruct.ap.internal.processor.DefaultVersionInformation.fromProcessingEnvironment(DefaultVersionInformation.java:95)  
	at org.mapstruct.ap.internal.processor.DefaultModelElementProcessorContext.<init>(DefaultModelElementProcessorContext.java:54)  
	at org.mapstruct.ap.MappingProcessor.processMapperElements(MappingProcessor.java:264)  
	at org.mapstruct.ap.MappingProcessor.process(MappingProcessor.java:166)  
	at org.jetbrains.jps.javac.APIWrappers$ProcessorWrapper.process(APIWrappers.java:59)  
	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:566)  
	at org.jetbrains.jps.javac.APIWrappers$1.invoke(APIWrappers.java:162)  
	at com.sun.proxy.$Proxy18.process(Unknown Source)  
	at jdk.compiler/com.sun.tools.javac.processing.JavacProcessingEnvironment.callProcessor(JavacProcessingEnvironment.java:980)  
	at jdk.compiler/com.sun.tools.javac.processing.JavacProcessingEnvironment.discoverAndRunProcs(JavacProcessingEnvironment.java:896)  
	at jdk.compiler/com.sun.tools.javac.processing.JavacProcessingEnvironment$Round.run(JavacProcessingEnvironment.java:1222)  
	at jdk.compiler/com.sun.tools.javac.processing.JavacProcessingEnvironment.doProcessing(JavacProcessingEnvironment.java:1334)  
	at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.processAnnotations(JavaCompiler.java:1258)  
	at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:936)  
	at jdk.compiler/com.sun.tools.javac.api.JavacTaskImpl.lambda$doCall$0(JavacTaskImpl.java:104)  
	at jdk.compiler/com.sun.tools.javac.api.JavacTaskImpl.handleExceptions(JavacTaskImpl.java:147)  
	at jdk.compiler/com.sun.tools.javac.api.JavacTaskImpl.doCall(JavacTaskImpl.java:100)  
	at jdk.compiler/com.sun.tools.javac.api.Ja

原因: mapStruct版本低了，估计遇到这个问题的朋友，都是引入了mybatisPlus，用的mapperStruct版本为1.2,如果无法升级版本，可以考虑按照如下解决方案处理。

解决方案:

编辑：要修复 IDEA 2020.3+ 中的错误，请升级到 1.4.1.Final 或更高版本。
如果您坚持使用旧版本，作为一种解决方法，您可以-Djps.track.ap.dependencies=false添加File | Settings | Build, Execution, Deployment | Compiler | User-local build process VM options (overrides Shared options)