java - Maven 程序集插件因 NullPointerException 失败？

Question

我收到 NullPointerException，但我不喜欢它。它是一个较大的构建，包含多个子模块(它们的 Maven 配置仅略有不同)，对于大多数模块来说它确实有效，但对于某些模块则不然。知道问题可能是什么吗？

[INFO] [assembly:assembly]
[INFO] Reading assembly descriptor: src/assemble/all.xml
[INFO] ------------------------------------------------------------------------
[ERROR] FATAL ERROR
[INFO] ------------------------------------------------------------------------
[INFO] null
[INFO] ------------------------------------------------------------------------
[INFO] Trace
java.lang.NullPointerException
at org.apache.maven.artifact.DefaultArtifact.equals(DefaultArtifact.java:358)
at java.util.HashMap.put(HashMap.java:376)
at java.util.HashSet.add(HashSet.java:200)
at java.util.AbstractCollection.addAll(AbstractCollection.java:305)
at org.apache.maven.plugin.assembly.artifact.DefaultDependencyResolver.buildManagedVersionMap(DefaultDependencyResolver.java:160)
at org.apache.maven.plugin.assembly.archive.DefaultAssemblyArchiver.createArchive(DefaultAssemblyArchiver.java:179)
at org.apache.maven.plugin.assembly.mojos.AbstractAssemblyMojo.execute(AbstractAssemblyMojo.java:370)
at org.apache.maven.plugin.DefaultPluginManager.executeMojo(DefaultPluginManager.java:483)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(DefaultLifecycleExecutor.java:678)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeStandaloneGoal(DefaultLifecycleExecutor.java:553)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoal(DefaultLifecycleExecutor.java:523)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalAndHandleFailures(DefaultLifecycleExecutor.java:371)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeTaskSegments(DefaultLifecycleExecutor.java:268)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.execute(DefaultLifecycleExecutor.java:181)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:356)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:137)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:356)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.codehaus.classworlds.Launcher.launchEnhanced(Launcher.java:315)
at org.codehaus.classworlds.Launcher.launch(Launcher.java:255)
at org.codehaus.classworlds.Launcher.mainWithExitCode(Launcher.java:430)
at org.codehaus.classworlds.Launcher.main(Launcher.java:375)
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 41 seconds
[INFO] Finished at: Fri Jun 19 10:44:03 CEST 2009
[INFO] Final Memory: 32M/99M
[INFO] ------------------------------------------------------------------------

Answer 1

查看头部修订版的第 358 行，我的猜测是某些地方没有定义版本。

我并不真正“了解”Maven，但我建议仔细检查您的版本。当然，我可能没有查看与您正在使用的相同的源代码 - 查看您实际版本的源代码，看看 DefaultArtifact.java 第 358 行的内容。