maven资源插件中奇怪的NullPointerException

一天大约两次，我们的构建中会出现NullPointerException：

[06:44:23]: [ERROR] Failed to execute goal org.apache.maven.plugins:maven-resources-plugin:2.5:resources (default-resources) on project spring-lib: Execution default-resources of goal org.apache.maven.plugins:maven-resources-plugin:2.5:resources failed. NullPointerException -> [Help 1]
[06:44:23]: org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.apache.maven.plugins:maven-resources-plugin:2.5:resources (default-resources) on project spring-lib: Execution default-resources of goal org.apache.maven.plugins:maven-resources-plugin:2.5:resources failed.
[06:44:23]: at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:225)
[06:44:23]: at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
[06:44:23]: at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
[06:44:23]: at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84)
[06:44:23]: at org.apache.maven.lifecycle.internal.LifecycleThreadedBuilder$1.call(LifecycleThreadedBuilder.java:167)
[06:44:23]: at org.apache.maven.lifecycle.internal.LifecycleThreadedBuilder$1.call(LifecycleThreadedBuilder.java:164)
[06:44:23]: at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
[06:44:23]: at java.util.concurrent.FutureTask.run(FutureTask.java:138)
[06:44:23]: at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
[06:44:23]: at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
[06:44:23]: at java.util.concurrent.FutureTask.run(FutureTask.java:138)
[06:44:23]: at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
[06:44:23]: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
[06:44:23]: at java.lang.Thread.run(Thread.java:619)
[06:44:23]: Caused by: org.apache.maven.plugin.PluginExecutionException: Execution default-resources of goal org.apache.maven.plugins:maven-resources-plugin:2.5:resources failed.
[06:44:23]: at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:110)
[06:44:23]: at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:209)
[06:44:23]: ... 13 more
[06:44:23]: Caused by: java.lang.NullPointerException
[06:44:23]: at java.util.ArrayList.<init>(ArrayList.java:131)
[06:44:23]: at org.apache.maven.shared.filtering.DefaultMavenResourcesFiltering.filteredFileExtension(DefaultMavenResourcesFiltering.java:115)
[06:44:23]: at org.apache.maven.shared.filtering.DefaultMavenResourcesFiltering.filterResources(DefaultMavenResourcesFiltering.java:264)
[06:44:23]: at org.apache.maven.plugin.resources.ResourcesMojo.execute(ResourcesMojo.java:310)
[06:44:23]: at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:101)
[06:44:23]: ... 14 more

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非常感谢为解决此问题提供的任何帮助。

尝试使用

-X

运行maven并分析调试输出。这可能会有帮助。至少对我来说，这经常发生

编辑：这是有问题的地方：

113 public boolean filteredFileExtension( String fileName, List userNonFilteredFileExtensions )
114 {
115 List nonFilteredFileExtensions = new ArrayList( getDefaultNonFilteredFileExtensions() );

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因为您是并行构建的，所以这可能是一种竞争条件。您真的应该在上提出一个问题。

问题是，当构建大约每10分钟运行一次时，这种情况很少发生。使用-X运行将降低构建速度。我对无用的日志也不感兴趣，直到这个问题再次出现。我没有更改maven插件代码。maven资源插件被标记为线程安全的，尽管可能存在错误。。。我也会在那里发布一个jira问题。我不是指代码，而是指你的有效POM。打开jira有助于跟踪这些讨厌的bug。我没有在pom.xmlopened中更改非过滤索引-希望在那里得到更多帮助。 113 public boolean filteredFileExtension( String fileName, List userNonFilteredFileExtensions )
114 {
115 List nonFilteredFileExtensions = new ArrayList( getDefaultNonFilteredFileExtensions() );
63 // ------------------------------------------------
64 // Plexus lifecycle
65 // ------------------------------------------------
66 public void initialize()
67 throws InitializationException
68 {
69 // jpg,jpeg,gif,bmp,png
70 this.defaultNonFilteredFileExtensions = new ArrayList( 5 );
71 this.defaultNonFilteredFileExtensions.add( "jpg" );
72 this.defaultNonFilteredFileExtensions.add( "jpeg" );
73 this.defaultNonFilteredFileExtensions.add( "gif" );
74 this.defaultNonFilteredFileExtensions.add( "bmp" );
75 this.defaultNonFilteredFileExtensions.add( "png" );
76 }