Cause: java.lang.NullPointerException

一、报错信息

Cause: java.lang.NullPointerException
	at org.jetbrains.plugins.gradle.tooling.serialization.internal.IdeaProjectSerializationService.<init>(IdeaProjectSerializationService.java:47)
	at org.jetbrains.plugins.gradle.model.ModelsHolder.initToolingSerializer(ModelsHolder.java:50)
	at org.jetbrains.plugins.gradle.service.project.GradleProjectResolver.doResolveProjectInfo(GradleProjectResolver.java:292)
	at org.jetbrains.plugins.gradle.service.project.GradleProjectResolver.access$200(GradleProjectResolver.java:60)
	at org.jetbrains.plugins.gradle.service.project.GradleProjectResolver$ProjectConnectionDataNodeFunction.fun(GradleProjectResolver.java:725)
	at org.jetbrains.plugins.gradle.service.project.GradleProjectResolver$ProjectConnectionDataNodeFunction.fun(GradleProjectResolver.java:708)
	at org.jetbrains.plugins.gradle.service.execution.GradleExecutionHelper.execute(GradleExecutionHelper.java:276)
	at org.jetbrains.plugins.gradle.service.project.GradleProjectResolver.resolveProjectInfo(GradleProjectResolver.java:125)
	at org.jetbrains.plugins.gradle.service.project.GradleProjectResolver.resolveProjectInfo(GradleProjectResolver.java:60)
	at com.intellij.openapi.externalSystem.service.remote.RemoteExternalSystemProjectResolverImpl.lambda$resolveProjectInfo$0(RemoteExternalSystemProjectResolverImpl.java:35)
	at com.intellij.openapi.externalSystem.service.remote.AbstractRemoteExternalSystemService.execute(AbstractRemoteExternalSystemService.java:57)
	at com.intellij.openapi.externalSystem.service.remote.RemoteExternalSystemProjectResolverImpl.resolveProjectInfo(RemoteExternalSystemProjectResolverImpl.java:35)
	at com.intellij.openapi.externalSystem.service.remote.wrapper.ExternalSystemProjectResolverWrapper.resolveProjectInfo(ExternalSystemProjectResolverWrapper.java:44)
	at com.intellij.openapi.externalSystem.service.internal.ExternalSystemResolveProjectTask.doExecute(ExternalSystemResolveProjectTask.java:100)
	at com.intellij.openapi.externalSystem.service.internal.AbstractExternalSystemTask.execute(AbstractExternalSystemTask.java:146)
	at com.intellij.openapi.externalSystem.service.internal.AbstractExternalSystemTask.execute(AbstractExternalSystemTask.java:132)
	at com.intellij.openapi.externalSystem.util.ExternalSystemUtil$3.executeImpl(ExternalSystemUtil.java:544)
	at com.intellij.openapi.externalSystem.util.ExternalSystemUtil$3.lambda$execute$1(ExternalSystemUtil.java:392)
	at com.intellij.openapi.project.DumbServiceImpl.suspendIndexingAndRun(DumbServiceImpl.java:150)
	at com.intellij.openapi.externalSystem.util.ExternalSystemUtil$3.execute(ExternalSystemUtil.java:392)
	at com.intellij.openapi.externalSystem.util.ExternalSystemUtil$5.run(ExternalSystemUtil.java:660)
	at com.intellij.openapi.progress.impl.CoreProgressManager$TaskRunnable.run(CoreProgressManager.java:888)
	at com.intellij.openapi.progress.impl.CoreProgressManager.lambda$runProcess$2(CoreProgressManager.java:163)
	at com.intellij.openapi.progress.impl.CoreProgressManager.registerIndicatorAndRun(CoreProgressManager.java:585)
	at com.intellij.openapi.progress.impl.CoreProgressManager.executeProcessUnderProgress(CoreProgressManager.java:531)
	at com.intellij.openapi.progress.impl.ProgressManagerImpl.executeProcessUnderProgress(ProgressManagerImpl.java:59)
	at com.intellij.openapi.progress.impl.CoreProgressManager.runProcess(CoreProgressManager.java:150)
	at com.intellij.openapi.progress.impl.CoreProgressManager$4.lambda$run$0(CoreProgressManager.java:402)
	at com.intellij.util.ConcurrencyUtil.runUnderThreadName(ConcurrencyUtil.java:221)
	at com.intellij.openapi.progress.impl.CoreProgressManager$4.run(CoreProgressManager.java:402)
	at com.intellij.openapi.application.impl.ApplicationImpl$1.run(ApplicationImpl.java:238)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)

二、报错原因

Android项目版本是3.5.0，支持的Java版本为JDK1.8，而Android Studio版本是4.0.1，默认使用Java11，导致冲突。正确的解决方法就是单独设置Android项目的JDK路径。

三、解决方法

1、安装和配置好JDK1.8

2、File——>Project Structure，可以看到当前项目的插件版本和Gradle版本信息。

3、在SDK Location的JDK Location中，选择你刚刚配置好的JAVA_HOME，然后Apply——>OK。

4、重新Sync，发现Build Successful，成功解决问题。

古人认为人世祸福的发生与人们的善恶行为有着必然的的因果联系，祸福不是毫无缘由地降临在世人身上，人的善恶行为才是自身得祸得福的直接诱因。即使不现报在自己身上，也会报应在自己的后代身上。善有善报恶有恶报，所以人们不可不谨慎行事。