ROS2 Java 示例：com.intellij.openapi.externalSystem.model.ExternalSystemException：无法在空对象上调用方法 split()
ROS2 Java Examples : com.intellij.openapi.externalSystem.model.ExternalSystemException: Cannot invoke method split() on null object
我克隆了 ROS2 Java examples 并尝试使用 Intelij、Gradle 6.3 和 Java 14 用 Gradle 构建它们。但是在项目导入期间抛出以下异常.
我已经完成了 ROS2 安装，我可以在 cpp 和 python 中成功 运行 个例子。
我复制了完整的堆栈跟踪。
我电脑里的ROS2版本是ros2-dashing-20200319-windows-amd64.
- Exception is: com.intellij.openapi.externalSystem.model.ExternalSystemException:
Cannot invoke method split() on null object at
org.jetbrains.plugins.gradle.model.ProjectImportAction.addBuildModels(ProjectImportAction.java:272)
at
org.jetbrains.plugins.gradle.model.ProjectImportAction.execute(ProjectImportAction.java:130)
at
org.jetbrains.plugins.gradle.model.ProjectImportAction.execute(ProjectImportAction.java:56)
at
org.gradle.tooling.internal.consumer.connection.InternalBuildActionAdapter.execute(InternalBuildActionAdapter.java:79)
at
org.gradle.tooling.internal.provider.runner.ClientProvidedPhasedActionRunner$ActionRunningListener.runAction(ClientProvidedPhasedActionRunner.java:120)
at
org.gradle.tooling.internal.provider.runner.ClientProvidedPhasedActionRunner$ActionRunningListener.run(ClientProvidedPhasedActionRunner.java:110)
at
org.gradle.tooling.internal.provider.runner.ClientProvidedPhasedActionRunner$ActionRunningListener.buildFinished(ClientProvidedPhasedActionRunner.java:104)
at jdk.internal.reflect.GeneratedMethodAccessor39.invoke(Unknown
Source) at
java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at
org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
at
org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
at
org.gradle.internal.event.DefaultListenerManager$ListenerDetails.dispatch(DefaultListenerManager.java:382)
at
org.gradle.internal.event.DefaultListenerManager$ListenerDetails.dispatch(DefaultListenerManager.java:364)
at
org.gradle.internal.event.AbstractBroadcastDispatch.dispatch(AbstractBroadcastDispatch.java:58)
at
org.gradle.internal.event.DefaultListenerManager$EventBroadcast$ListenerDispatch.dispatch(DefaultListenerManager.java:352)
at
org.gradle.internal.event.DefaultListenerManager$EventBroadcast$ListenerDispatch.dispatch(DefaultListenerManager.java:339)
at
org.gradle.internal.event.AbstractBroadcastDispatch.dispatch(AbstractBroadcastDispatch.java:42)
at
org.gradle.internal.event.BroadcastDispatch$SingletonDispatch.dispatch(BroadcastDispatch.java:231)
at
org.gradle.internal.event.BroadcastDispatch$SingletonDispatch.dispatch(BroadcastDispatch.java:150)
at
org.gradle.internal.event.AbstractBroadcastDispatch.dispatch(AbstractBroadcastDispatch.java:58)
at
org.gradle.internal.event.BroadcastDispatch$CompositeDispatch.dispatch(BroadcastDispatch.java:325)
at
org.gradle.internal.event.BroadcastDispatch$CompositeDispatch.dispatch(BroadcastDispatch.java:235)
at
org.gradle.internal.event.ListenerBroadcast.dispatch(ListenerBroadcast.java:141)
at
org.gradle.internal.event.ListenerBroadcast.dispatch(ListenerBroadcast.java:37)
at
org.gradle.internal.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:94)
at com.sun.proxy.$Proxy18.buildFinished(Unknown Source) at
org.gradle.initialization.DefaultGradleLauncher.finishBuild(DefaultGradleLauncher.java:184)
at
org.gradle.initialization.DefaultGradleLauncher.finishBuild(DefaultGradleLauncher.java:127)
at
org.gradle.internal.invocation.GradleBuildController.create(GradleBuildController.java:75)
at
org.gradle.internal.invocation.GradleBuildController.create(GradleBuildController.java:67)
at
org.gradle.internal.work.DefaultWorkerLeaseService.withLocks(DefaultWorkerLeaseService.java:189)
at
org.gradle.internal.work.StopShieldingWorkerLeaseService.withLocks(StopShieldingWorkerLeaseService.java:40)
at
org.gradle.internal.invocation.GradleBuildController.doBuild(GradleBuildController.java:67)
at
org.gradle.internal.invocation.GradleBuildController.run(GradleBuildController.java:56)
at
org.gradle.tooling.internal.provider.runner.ClientProvidedPhasedActionRunner.run(ClientProvidedPhasedActionRunner.java:60)
at
org.gradle.launcher.exec.ChainingBuildActionRunner.run(ChainingBuildActionRunner.java:35)
at
org.gradle.launcher.exec.ChainingBuildActionRunner.run(ChainingBuildActionRunner.java:35)
at
org.gradle.launcher.exec.BuildOutcomeReportingBuildActionRunner.run(BuildOutcomeReportingBuildActionRunner.java:63)
at
org.gradle.tooling.internal.provider.ValidatingBuildActionRunner.run(ValidatingBuildActionRunner.java:32)
at
org.gradle.launcher.exec.BuildCompletionNotifyingBuildActionRunner.run(BuildCompletionNotifyingBuildActionRunner.java:39)
at
org.gradle.launcher.exec.RunAsBuildOperationBuildActionRunner.call(RunAsBuildOperationBuildActionRunner.java:51)
at
org.gradle.launcher.exec.RunAsBuildOperationBuildActionRunner.call(RunAsBuildOperationBuildActionRunner.java:45)
at
org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:416)
at
org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:406)
at
org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:165)
at
org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:250)
at
org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:158)
at
org.gradle.internal.operations.DefaultBuildOperationExecutor.call(DefaultBuildOperationExecutor.java:102)
at
org.gradle.internal.operations.DelegatingBuildOperationExecutor.call(DelegatingBuildOperationExecutor.java:36)
at
org.gradle.launcher.exec.RunAsBuildOperationBuildActionRunner.run(RunAsBuildOperationBuildActionRunner.java:45)
at
org.gradle.launcher.exec.InProcessBuildActionExecuter.transform(InProcessBuildActionExecuter.java:50)
at
org.gradle.launcher.exec.InProcessBuildActionExecuter.transform(InProcessBuildActionExecuter.java:47)
at
org.gradle.composite.internal.DefaultRootBuildState.run(DefaultRootBuildState.java:80)
at
org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:47)
at
org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:31)
at
org.gradle.launcher.exec.BuildTreeScopeBuildActionExecuter.execute(BuildTreeScopeBuildActionExecuter.java:42)
at
org.gradle.launcher.exec.BuildTreeScopeBuildActionExecuter.execute(BuildTreeScopeBuildActionExecuter.java:28)
at
org.gradle.tooling.internal.provider.ContinuousBuildActionExecuter.execute(ContinuousBuildActionExecuter.java:78)
at
org.gradle.tooling.internal.provider.ContinuousBuildActionExecuter.execute(ContinuousBuildActionExecuter.java:52)
at
org.gradle.tooling.internal.provider.SubscribableBuildActionExecuter.execute(SubscribableBuildActionExecuter.java:60)
at
org.gradle.tooling.internal.provider.SubscribableBuildActionExecuter.execute(SubscribableBuildActionExecuter.java:38)
at
org.gradle.tooling.internal.provider.SessionScopeBuildActionExecuter.execute(SessionScopeBuildActionExecuter.java:68)
at
org.gradle.tooling.internal.provider.SessionScopeBuildActionExecuter.execute(SessionScopeBuildActionExecuter.java:38)
at
org.gradle.tooling.internal.provider.GradleThreadBuildActionExecuter.execute(GradleThreadBuildActionExecuter.java:37)
at
org.gradle.tooling.internal.provider.GradleThreadBuildActionExecuter.execute(GradleThreadBuildActionExecuter.java:26)
at
org.gradle.tooling.internal.provider.ParallelismConfigurationBuildActionExecuter.execute(ParallelismConfigurationBuildActionExecuter.java:43)
at
org.gradle.tooling.internal.provider.ParallelismConfigurationBuildActionExecuter.execute(ParallelismConfigurationBuildActionExecuter.java:29)
at
org.gradle.tooling.internal.provider.StartParamsValidatingActionExecuter.execute(StartParamsValidatingActionExecuter.java:60)
at
org.gradle.tooling.internal.provider.StartParamsValidatingActionExecuter.execute(StartParamsValidatingActionExecuter.java:32)
at
org.gradle.tooling.internal.provider.SessionFailureReportingActionExecuter.execute(SessionFailureReportingActionExecuter.java:55)
at
org.gradle.tooling.internal.provider.SessionFailureReportingActionExecuter.execute(SessionFailureReportingActionExecuter.java:41)
at
org.gradle.tooling.internal.provider.SetupLoggingActionExecuter.execute(SetupLoggingActionExecuter.java:48)
at
org.gradle.tooling.internal.provider.SetupLoggingActionExecuter.execute(SetupLoggingActionExecuter.java:32)
at
org.gradle.launcher.daemon.server.exec.ExecuteBuild.doBuild(ExecuteBuild.java:68)
at
org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:37)
at
org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:104)
at
org.gradle.launcher.daemon.server.exec.WatchForDisconnection.execute(WatchForDisconnection.java:39)
at
org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:104)
at
org.gradle.launcher.daemon.server.exec.ResetDeprecationLogger.execute(ResetDeprecationLogger.java:29)
at
org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:104)
at
org.gradle.launcher.daemon.server.exec.RequestStopIfSingleUsedDaemon.execute(RequestStopIfSingleUsedDaemon.java:35)
at
org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:104)
at
org.gradle.launcher.daemon.server.exec.ForwardClientInput.create(ForwardClientInput.java:78)
at
org.gradle.launcher.daemon.server.exec.ForwardClientInput.create(ForwardClientInput.java:75)
at org.gradle.util.Swapper.swap(Swapper.java:38) at
org.gradle.launcher.daemon.server.exec.ForwardClientInput.execute(ForwardClientInput.java:75)
at
org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:104)
at
org.gradle.launcher.daemon.server.exec.LogAndCheckHealth.execute(LogAndCheckHealth.java:55)
at
org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:104)
at
org.gradle.launcher.daemon.server.exec.LogToClient.doBuild(LogToClient.java:63)
at
org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:37)
at
org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:104)
at
org.gradle.launcher.daemon.server.exec.EstablishBuildEnvironment.doBuild(EstablishBuildEnvironment.java:82)
at
org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:37)
at
org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:104)
at
org.gradle.launcher.daemon.server.exec.StartBuildOrRespondWithBusy.run(StartBuildOrRespondWithBusy.java:52)
at
org.gradle.launcher.daemon.server.DaemonStateCoordinator.run(DaemonStateCoordinator.java:297)
at
org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:64)
at
org.gradle.internal.concurrent.ManagedExecutorImpl.run(ManagedExecutorImpl.java:48)
at
org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:56)
java.lang.NullPointerException: Cannot invoke method split() on null
object at
org.codehaus.groovy.runtime.NullObject.invokeMethod(NullObject.java:91)
at
org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.call(PogoMetaClassSite.java:43)
at
org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:47)
at
org.codehaus.groovy.runtime.callsite.NullCallSite.call(NullCallSite.java:34)
at
org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:47)
at
org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.call(PogoMetaClassSite.java:52)
at
org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:127)
at
org.ros2.tools.gradle.JavaAmentPluginExtension.updateJavaDependencies(JavaAmentPluginExtension.groovy:58)
at jdk.internal.reflect.GeneratedMethodAccessor81.invoke(Unknown
Source) at
java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564) at
org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:101)
at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:323) at
groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1217) at
org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodOnCurrentN(ScriptBytecodeAdapter.java:94)
at
org.ros2.tools.gradle.JavaAmentPluginExtension.this$dist$invoke(JavaAmentPluginExtension.groovy)
at
org.ros2.tools.gradle.JavaAmentPluginExtension.methodMissing(JavaAmentPluginExtension.groovy)
at jdk.internal.reflect.GeneratedMethodAccessor80.invoke(Unknown
Source) at
java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564) at
org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:101)
at
groovy.lang.MetaClassImpl.invokeMissingMethod(MetaClassImpl.java:958)
at
groovy.lang.MetaClassImpl.invokePropertyOrMissing(MetaClassImpl.java:1286)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1219)
at
org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.callCurrent(PogoMetaClassSite.java:64)
at
org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:160)
at
org.ros2.tools.gradle.JavaAmentPluginExtension.beforeResolve(JavaAmentPluginExtension.groovy:69)
at jdk.internal.reflect.GeneratedMethodAccessor79.invoke(Unknown
Source) at
java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564) at
org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
at
org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
at
org.gradle.internal.event.DefaultListenerManager$ListenerDetails.dispatch(DefaultListenerManager.java:382)
at
org.gradle.internal.event.DefaultListenerManager$ListenerDetails.dispatch(DefaultListenerManager.java:364)
at
org.gradle.internal.event.AbstractBroadcastDispatch.dispatch(AbstractBroadcastDispatch.java:58)
at
org.gradle.internal.event.DefaultListenerManager$EventBroadcast$ListenerDispatch.dispatch(DefaultListenerManager.java:352)
at
org.gradle.internal.event.DefaultListenerManager$EventBroadcast$ListenerDispatch.dispatch(DefaultListenerManager.java:339)
at
org.gradle.internal.event.AbstractBroadcastDispatch.dispatch(AbstractBroadcastDispatch.java:42)
at
org.gradle.internal.event.BroadcastDispatch$SingletonDispatch.dispatch(BroadcastDispatch.java:231)
at
org.gradle.internal.event.BroadcastDispatch$SingletonDispatch.dispatch(BroadcastDispatch.java:150)
at
org.gradle.internal.event.ListenerBroadcast.dispatch(ListenerBroadcast.java:141)
at
org.gradle.internal.event.ListenerBroadcast.dispatch(ListenerBroadcast.java:37)
at
org.gradle.internal.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:94)
at com.sun.proxy.$Proxy29.beforeResolve(Unknown Source) at
org.gradle.api.internal.artifacts.configurations.DefaultConfiguration.performPreResolveActions(DefaultConfiguration.java:674)
at
org.gradle.api.internal.artifacts.configurations.DefaultConfiguration.access0(DefaultConfiguration.java:141)
at
org.gradle.api.internal.artifacts.configurations.DefaultConfiguration.run(DefaultConfiguration.java:618)
at
org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:402)
at
org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:394)
at
org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:165)
at
org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:250)
at
org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:158)
at
org.gradle.internal.operations.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:92)
at
org.gradle.internal.operations.DelegatingBuildOperationExecutor.run(DelegatingBuildOperationExecutor.java:31)
at
org.gradle.api.internal.artifacts.configurations.DefaultConfiguration.resolveGraphIfRequired(DefaultConfiguration.java:611)
at
org.gradle.api.internal.artifacts.configurations.DefaultConfiguration.lambda$resolveExclusively(DefaultConfiguration.java:592)
at
org.gradle.api.internal.project.DefaultProjectStateRegistry$SafeExclusiveLockImpl.withLock(DefaultProjectStateRegistry.java:289)
at
org.gradle.api.internal.artifacts.configurations.DefaultConfiguration.resolveExclusively(DefaultConfiguration.java:590)
at
org.gradle.api.internal.artifacts.configurations.DefaultConfiguration.resolveToStateOrLater(DefaultConfiguration.java:576)
at
org.gradle.api.internal.artifacts.configurations.DefaultConfiguration.getResolvedConfiguration(DefaultConfiguration.java:554)
at
org.gradle.api.internal.artifacts.configurations.DefaultConfiguration_Decorated.getResolvedConfiguration(Unknown
Source) at
org.jetbrains.plugins.gradle.tooling.util.resolve.DependencyResolverImpl.resolveDependencies(DependencyResolverImpl.java:153)
at
org.jetbrains.plugins.gradle.tooling.util.resolve.DependencyResolverImpl.getDependencies(DependencyResolverImpl.java:537)
at
org.jetbrains.plugins.gradle.tooling.util.resolve.DependencyResolverImpl.resolveDependencies(DependencyResolverImpl.java:131)
at
org.jetbrains.plugins.gradle.tooling.util.DependencyResolver$resolveDependencies.call(Unknown
Source) at
org.jetbrains.plugins.gradle.tooling.builder.ExternalProjectBuilderImpl$_getSourceSets_closure1.doCall(ExternalProjectBuilderImpl.groovy:440)
at
java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native
Method) at
java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at
java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564) at
org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:101)
at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:323) at
org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:263)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1041)
at groovy.lang.Closure.call(Closure.java:405) at
groovy.lang.Closure.call(Closure.java:421) at
org.gradle.util.ClosureBackedAction.execute(ClosureBackedAction.java:71)
at
org.gradle.util.ConfigureUtil.configureTarget(ConfigureUtil.java:154)
at org.gradle.util.ConfigureUtil.configure(ConfigureUtil.java:105)
at
org.gradle.util.ConfigureUtil$WrappedConfigureAction.execute(ConfigureUtil.java:166)
at
org.gradle.api.internal.DefaultDomainObjectCollection.all(DefaultDomainObjectCollection.java:163)
at
org.gradle.api.internal.DefaultDomainObjectCollection.all(DefaultDomainObjectCollection.java:198)
at org.gradle.api.DomainObjectCollection$all.call(Unknown Source)
at
org.jetbrains.plugins.gradle.tooling.builder.ExternalProjectBuilderImpl.getSourceSets(ExternalProjectBuilderImpl.groovy:240)
at
org.jetbrains.plugins.gradle.tooling.builder.ExternalProjectBuilderImpl.doBuild(ExternalProjectBuilderImpl.groovy:101)
at
org.jetbrains.plugins.gradle.tooling.builder.ExternalProjectBuilderImpl.buildAll(ExternalProjectBuilderImpl.groovy:70)
at
org.jetbrains.plugins.gradle.tooling.internal.ExtraModelBuilder.buildAll(ExtraModelBuilder.java:101)
at
org.gradle.tooling.provider.model.internal.DefaultToolingModelBuilderRegistry$BuildOperationWrappingToolingModelBuilder.create(DefaultToolingModelBuilderRegistry.java:104)
at
org.gradle.api.internal.project.DefaultProjectStateRegistry.withLenientState(DefaultProjectStateRegistry.java:134)
at
org.gradle.tooling.provider.model.internal.DefaultToolingModelBuilderRegistry$BuildOperationWrappingToolingModelBuilder.call(DefaultToolingModelBuilderRegistry.java:100)
at
org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:416)
at
org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:406)
at
..............................................................................................
org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:56)
at java.base/java.lang.Thread.run(Thread.java:832)
从命令行构建 ros2_java_examples 也失败了，但出现了不同的错误。
ros2_java_examples\rcljava_examples> gradle build
> Task :checkAmentProperties FAILED
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':checkAmentProperties'.
> Missing Ament Gradle property: ament.build_space
虽然这个问题没有解决，但可以通过直接使用命令行来解决它，正如评论中提到的那样。
在构建 ROS2 Java 示例之前，需要遵循所有前面的步骤。
我克隆了 ROS2 Java examples 并尝试使用 Intelij、Gradle 6.3 和 Java 14 用 Gradle 构建它们。但是在项目导入期间抛出以下异常. 我已经完成了 ROS2 安装，我可以在 cpp 和 python 中成功 运行 个例子。 我复制了完整的堆栈跟踪。 我电脑里的ROS2版本是ros2-dashing-20200319-windows-amd64.
- Exception is: com.intellij.openapi.externalSystem.model.ExternalSystemException: Cannot invoke method split() on null object at org.jetbrains.plugins.gradle.model.ProjectImportAction.addBuildModels(ProjectImportAction.java:272) at org.jetbrains.plugins.gradle.model.ProjectImportAction.execute(ProjectImportAction.java:130) at org.jetbrains.plugins.gradle.model.ProjectImportAction.execute(ProjectImportAction.java:56) at org.gradle.tooling.internal.consumer.connection.InternalBuildActionAdapter.execute(InternalBuildActionAdapter.java:79) at org.gradle.tooling.internal.provider.runner.ClientProvidedPhasedActionRunner$ActionRunningListener.runAction(ClientProvidedPhasedActionRunner.java:120) at org.gradle.tooling.internal.provider.runner.ClientProvidedPhasedActionRunner$ActionRunningListener.run(ClientProvidedPhasedActionRunner.java:110) at org.gradle.tooling.internal.provider.runner.ClientProvidedPhasedActionRunner$ActionRunningListener.buildFinished(ClientProvidedPhasedActionRunner.java:104) at jdk.internal.reflect.GeneratedMethodAccessor39.invoke(Unknown Source) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36) at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24) at org.gradle.internal.event.DefaultListenerManager$ListenerDetails.dispatch(DefaultListenerManager.java:382) at org.gradle.internal.event.DefaultListenerManager$ListenerDetails.dispatch(DefaultListenerManager.java:364) at org.gradle.internal.event.AbstractBroadcastDispatch.dispatch(AbstractBroadcastDispatch.java:58) at org.gradle.internal.event.DefaultListenerManager$EventBroadcast$ListenerDispatch.dispatch(DefaultListenerManager.java:352) at org.gradle.internal.event.DefaultListenerManager$EventBroadcast$ListenerDispatch.dispatch(DefaultListenerManager.java:339) at org.gradle.internal.event.AbstractBroadcastDispatch.dispatch(AbstractBroadcastDispatch.java:42) at org.gradle.internal.event.BroadcastDispatch$SingletonDispatch.dispatch(BroadcastDispatch.java:231) at org.gradle.internal.event.BroadcastDispatch$SingletonDispatch.dispatch(BroadcastDispatch.java:150) at org.gradle.internal.event.AbstractBroadcastDispatch.dispatch(AbstractBroadcastDispatch.java:58) at org.gradle.internal.event.BroadcastDispatch$CompositeDispatch.dispatch(BroadcastDispatch.java:325) at org.gradle.internal.event.BroadcastDispatch$CompositeDispatch.dispatch(BroadcastDispatch.java:235) at org.gradle.internal.event.ListenerBroadcast.dispatch(ListenerBroadcast.java:141) at org.gradle.internal.event.ListenerBroadcast.dispatch(ListenerBroadcast.java:37) at org.gradle.internal.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:94) at com.sun.proxy.$Proxy18.buildFinished(Unknown Source) at org.gradle.initialization.DefaultGradleLauncher.finishBuild(DefaultGradleLauncher.java:184) at org.gradle.initialization.DefaultGradleLauncher.finishBuild(DefaultGradleLauncher.java:127) at org.gradle.internal.invocation.GradleBuildController.create(GradleBuildController.java:75) at org.gradle.internal.invocation.GradleBuildController.create(GradleBuildController.java:67) at org.gradle.internal.work.DefaultWorkerLeaseService.withLocks(DefaultWorkerLeaseService.java:189) at org.gradle.internal.work.StopShieldingWorkerLeaseService.withLocks(StopShieldingWorkerLeaseService.java:40) at org.gradle.internal.invocation.GradleBuildController.doBuild(GradleBuildController.java:67) at org.gradle.internal.invocation.GradleBuildController.run(GradleBuildController.java:56) at org.gradle.tooling.internal.provider.runner.ClientProvidedPhasedActionRunner.run(ClientProvidedPhasedActionRunner.java:60) at org.gradle.launcher.exec.ChainingBuildActionRunner.run(ChainingBuildActionRunner.java:35) at org.gradle.launcher.exec.ChainingBuildActionRunner.run(ChainingBuildActionRunner.java:35) at org.gradle.launcher.exec.BuildOutcomeReportingBuildActionRunner.run(BuildOutcomeReportingBuildActionRunner.java:63) at org.gradle.tooling.internal.provider.ValidatingBuildActionRunner.run(ValidatingBuildActionRunner.java:32) at org.gradle.launcher.exec.BuildCompletionNotifyingBuildActionRunner.run(BuildCompletionNotifyingBuildActionRunner.java:39) at org.gradle.launcher.exec.RunAsBuildOperationBuildActionRunner.call(RunAsBuildOperationBuildActionRunner.java:51) at org.gradle.launcher.exec.RunAsBuildOperationBuildActionRunner.call(RunAsBuildOperationBuildActionRunner.java:45) at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:416) at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:406) at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:165) at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:250) at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:158) at org.gradle.internal.operations.DefaultBuildOperationExecutor.call(DefaultBuildOperationExecutor.java:102) at org.gradle.internal.operations.DelegatingBuildOperationExecutor.call(DelegatingBuildOperationExecutor.java:36) at org.gradle.launcher.exec.RunAsBuildOperationBuildActionRunner.run(RunAsBuildOperationBuildActionRunner.java:45) at org.gradle.launcher.exec.InProcessBuildActionExecuter.transform(InProcessBuildActionExecuter.java:50) at org.gradle.launcher.exec.InProcessBuildActionExecuter.transform(InProcessBuildActionExecuter.java:47) at org.gradle.composite.internal.DefaultRootBuildState.run(DefaultRootBuildState.java:80) at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:47) at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:31) at org.gradle.launcher.exec.BuildTreeScopeBuildActionExecuter.execute(BuildTreeScopeBuildActionExecuter.java:42) at org.gradle.launcher.exec.BuildTreeScopeBuildActionExecuter.execute(BuildTreeScopeBuildActionExecuter.java:28) at org.gradle.tooling.internal.provider.ContinuousBuildActionExecuter.execute(ContinuousBuildActionExecuter.java:78) at org.gradle.tooling.internal.provider.ContinuousBuildActionExecuter.execute(ContinuousBuildActionExecuter.java:52) at org.gradle.tooling.internal.provider.SubscribableBuildActionExecuter.execute(SubscribableBuildActionExecuter.java:60) at org.gradle.tooling.internal.provider.SubscribableBuildActionExecuter.execute(SubscribableBuildActionExecuter.java:38) at org.gradle.tooling.internal.provider.SessionScopeBuildActionExecuter.execute(SessionScopeBuildActionExecuter.java:68) at org.gradle.tooling.internal.provider.SessionScopeBuildActionExecuter.execute(SessionScopeBuildActionExecuter.java:38) at org.gradle.tooling.internal.provider.GradleThreadBuildActionExecuter.execute(GradleThreadBuildActionExecuter.java:37) at org.gradle.tooling.internal.provider.GradleThreadBuildActionExecuter.execute(GradleThreadBuildActionExecuter.java:26) at org.gradle.tooling.internal.provider.ParallelismConfigurationBuildActionExecuter.execute(ParallelismConfigurationBuildActionExecuter.java:43) at org.gradle.tooling.internal.provider.ParallelismConfigurationBuildActionExecuter.execute(ParallelismConfigurationBuildActionExecuter.java:29) at org.gradle.tooling.internal.provider.StartParamsValidatingActionExecuter.execute(StartParamsValidatingActionExecuter.java:60) at org.gradle.tooling.internal.provider.StartParamsValidatingActionExecuter.execute(StartParamsValidatingActionExecuter.java:32) at org.gradle.tooling.internal.provider.SessionFailureReportingActionExecuter.execute(SessionFailureReportingActionExecuter.java:55) at org.gradle.tooling.internal.provider.SessionFailureReportingActionExecuter.execute(SessionFailureReportingActionExecuter.java:41) at org.gradle.tooling.internal.provider.SetupLoggingActionExecuter.execute(SetupLoggingActionExecuter.java:48) at org.gradle.tooling.internal.provider.SetupLoggingActionExecuter.execute(SetupLoggingActionExecuter.java:32) at org.gradle.launcher.daemon.server.exec.ExecuteBuild.doBuild(ExecuteBuild.java:68) at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:37) at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:104) at org.gradle.launcher.daemon.server.exec.WatchForDisconnection.execute(WatchForDisconnection.java:39) at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:104) at org.gradle.launcher.daemon.server.exec.ResetDeprecationLogger.execute(ResetDeprecationLogger.java:29) at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:104) at org.gradle.launcher.daemon.server.exec.RequestStopIfSingleUsedDaemon.execute(RequestStopIfSingleUsedDaemon.java:35) at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:104) at org.gradle.launcher.daemon.server.exec.ForwardClientInput.create(ForwardClientInput.java:78) at org.gradle.launcher.daemon.server.exec.ForwardClientInput.create(ForwardClientInput.java:75) at org.gradle.util.Swapper.swap(Swapper.java:38) at org.gradle.launcher.daemon.server.exec.ForwardClientInput.execute(ForwardClientInput.java:75) at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:104) at org.gradle.launcher.daemon.server.exec.LogAndCheckHealth.execute(LogAndCheckHealth.java:55) at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:104) at org.gradle.launcher.daemon.server.exec.LogToClient.doBuild(LogToClient.java:63) at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:37) at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:104) at org.gradle.launcher.daemon.server.exec.EstablishBuildEnvironment.doBuild(EstablishBuildEnvironment.java:82) at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:37) at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:104) at org.gradle.launcher.daemon.server.exec.StartBuildOrRespondWithBusy.run(StartBuildOrRespondWithBusy.java:52) at org.gradle.launcher.daemon.server.DaemonStateCoordinator.run(DaemonStateCoordinator.java:297) at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:64) at org.gradle.internal.concurrent.ManagedExecutorImpl.run(ManagedExecutorImpl.java:48) at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:56) java.lang.NullPointerException: Cannot invoke method split() on null object at org.codehaus.groovy.runtime.NullObject.invokeMethod(NullObject.java:91) at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.call(PogoMetaClassSite.java:43) at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:47) at org.codehaus.groovy.runtime.callsite.NullCallSite.call(NullCallSite.java:34) at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:47) at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.call(PogoMetaClassSite.java:52) at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:127) at org.ros2.tools.gradle.JavaAmentPluginExtension.updateJavaDependencies(JavaAmentPluginExtension.groovy:58) at jdk.internal.reflect.GeneratedMethodAccessor81.invoke(Unknown Source) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:564) at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:101) at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:323) at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1217) at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodOnCurrentN(ScriptBytecodeAdapter.java:94) at org.ros2.tools.gradle.JavaAmentPluginExtension.this$dist$invoke(JavaAmentPluginExtension.groovy) at org.ros2.tools.gradle.JavaAmentPluginExtension.methodMissing(JavaAmentPluginExtension.groovy) at jdk.internal.reflect.GeneratedMethodAccessor80.invoke(Unknown Source) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:564) at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:101) at groovy.lang.MetaClassImpl.invokeMissingMethod(MetaClassImpl.java:958) at groovy.lang.MetaClassImpl.invokePropertyOrMissing(MetaClassImpl.java:1286) at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1219) at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.callCurrent(PogoMetaClassSite.java:64) at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:160) at org.ros2.tools.gradle.JavaAmentPluginExtension.beforeResolve(JavaAmentPluginExtension.groovy:69) at jdk.internal.reflect.GeneratedMethodAccessor79.invoke(Unknown Source) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:564) at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36) at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24) at org.gradle.internal.event.DefaultListenerManager$ListenerDetails.dispatch(DefaultListenerManager.java:382) at org.gradle.internal.event.DefaultListenerManager$ListenerDetails.dispatch(DefaultListenerManager.java:364) at org.gradle.internal.event.AbstractBroadcastDispatch.dispatch(AbstractBroadcastDispatch.java:58) at org.gradle.internal.event.DefaultListenerManager$EventBroadcast$ListenerDispatch.dispatch(DefaultListenerManager.java:352) at org.gradle.internal.event.DefaultListenerManager$EventBroadcast$ListenerDispatch.dispatch(DefaultListenerManager.java:339) at org.gradle.internal.event.AbstractBroadcastDispatch.dispatch(AbstractBroadcastDispatch.java:42) at org.gradle.internal.event.BroadcastDispatch$SingletonDispatch.dispatch(BroadcastDispatch.java:231) at org.gradle.internal.event.BroadcastDispatch$SingletonDispatch.dispatch(BroadcastDispatch.java:150) at org.gradle.internal.event.ListenerBroadcast.dispatch(ListenerBroadcast.java:141) at org.gradle.internal.event.ListenerBroadcast.dispatch(ListenerBroadcast.java:37) at org.gradle.internal.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:94) at com.sun.proxy.$Proxy29.beforeResolve(Unknown Source) at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration.performPreResolveActions(DefaultConfiguration.java:674) at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration.access0(DefaultConfiguration.java:141) at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration.run(DefaultConfiguration.java:618) at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:402) at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:394) at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:165) at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:250) at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:158) at org.gradle.internal.operations.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:92) at org.gradle.internal.operations.DelegatingBuildOperationExecutor.run(DelegatingBuildOperationExecutor.java:31) at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration.resolveGraphIfRequired(DefaultConfiguration.java:611) at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration.lambda$resolveExclusively(DefaultConfiguration.java:592) at org.gradle.api.internal.project.DefaultProjectStateRegistry$SafeExclusiveLockImpl.withLock(DefaultProjectStateRegistry.java:289) at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration.resolveExclusively(DefaultConfiguration.java:590) at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration.resolveToStateOrLater(DefaultConfiguration.java:576) at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration.getResolvedConfiguration(DefaultConfiguration.java:554) at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration_Decorated.getResolvedConfiguration(Unknown Source) at org.jetbrains.plugins.gradle.tooling.util.resolve.DependencyResolverImpl.resolveDependencies(DependencyResolverImpl.java:153) at org.jetbrains.plugins.gradle.tooling.util.resolve.DependencyResolverImpl.getDependencies(DependencyResolverImpl.java:537) at org.jetbrains.plugins.gradle.tooling.util.resolve.DependencyResolverImpl.resolveDependencies(DependencyResolverImpl.java:131) at org.jetbrains.plugins.gradle.tooling.util.DependencyResolver$resolveDependencies.call(Unknown Source) at org.jetbrains.plugins.gradle.tooling.builder.ExternalProjectBuilderImpl$_getSourceSets_closure1.doCall(ExternalProjectBuilderImpl.groovy:440) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:564) at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:101) at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:323) at org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:263) at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1041) at groovy.lang.Closure.call(Closure.java:405) at groovy.lang.Closure.call(Closure.java:421) at org.gradle.util.ClosureBackedAction.execute(ClosureBackedAction.java:71) at org.gradle.util.ConfigureUtil.configureTarget(ConfigureUtil.java:154) at org.gradle.util.ConfigureUtil.configure(ConfigureUtil.java:105) at org.gradle.util.ConfigureUtil$WrappedConfigureAction.execute(ConfigureUtil.java:166) at org.gradle.api.internal.DefaultDomainObjectCollection.all(DefaultDomainObjectCollection.java:163) at org.gradle.api.internal.DefaultDomainObjectCollection.all(DefaultDomainObjectCollection.java:198) at org.gradle.api.DomainObjectCollection$all.call(Unknown Source) at org.jetbrains.plugins.gradle.tooling.builder.ExternalProjectBuilderImpl.getSourceSets(ExternalProjectBuilderImpl.groovy:240) at org.jetbrains.plugins.gradle.tooling.builder.ExternalProjectBuilderImpl.doBuild(ExternalProjectBuilderImpl.groovy:101) at org.jetbrains.plugins.gradle.tooling.builder.ExternalProjectBuilderImpl.buildAll(ExternalProjectBuilderImpl.groovy:70) at org.jetbrains.plugins.gradle.tooling.internal.ExtraModelBuilder.buildAll(ExtraModelBuilder.java:101) at org.gradle.tooling.provider.model.internal.DefaultToolingModelBuilderRegistry$BuildOperationWrappingToolingModelBuilder.create(DefaultToolingModelBuilderRegistry.java:104) at org.gradle.api.internal.project.DefaultProjectStateRegistry.withLenientState(DefaultProjectStateRegistry.java:134) at org.gradle.tooling.provider.model.internal.DefaultToolingModelBuilderRegistry$BuildOperationWrappingToolingModelBuilder.call(DefaultToolingModelBuilderRegistry.java:100) at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:416) at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:406) at .............................................................................................. org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:56) at java.base/java.lang.Thread.run(Thread.java:832)
从命令行构建 ros2_java_examples 也失败了，但出现了不同的错误。
ros2_java_examples\rcljava_examples> gradle build
> Task :checkAmentProperties FAILED
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':checkAmentProperties'.
> Missing Ament Gradle property: ament.build_space
虽然这个问题没有解决，但可以通过直接使用命令行来解决它，正如评论中提到的那样。
在构建 ROS2 Java 示例之前，需要遵循所有前面的步骤。