大约每天两次，我们在构建中得到一个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
这是随机发生的，下一次构建不会失败。
我已经搜索了此失败，但一无所获。我有这种直觉，这可能是由于maven-resources-plugin中的并发问题引起的。
我们使用maven-resources-plugin 2.4.3以及现在的2.5遇到了这个错误。我们的Maven版本是3.0.3。
我们使用以下参数在TeamCity上执行构建：
Goals: install
Additional Maven command line parameters: -T 2C -e -P!releasex,integration
-Dmaven.test.failure.ignore=true -Dmaven.test.error.ignore=true
-Dmaven.test.haltafterfailure=false -Dmaven.junit.timeout=1000000
-DwarProject.packaging=jar
为解决此问题提供了各种帮助。
最佳答案
尝试使用-X运行maven并分析调试输出。这可能会有所帮助。至少对我来说，它经常出现。
编辑：这是有问题的地方：
113 public booleanfilteredFileExtension（String fileName，List userNonFilteredFileExtensions）114 {115 List nonFilteredFileExtensions = new ArrayList（getDefaultNonFilteredFileExtensions（））;
getDefault ..返回null。您是否以某种方式更改了nonFilteredExts？因为默认情况下在这里填充它们：
63 // --------------------------------------------- --- 64 //丛生命周期65 // ----------------------------------- ------------- 66 public void initialize（）67引发InitializationException 68 {69 // jpg，jpeg，gif，bmp，png 70此.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}
由于您是并行构建的，因此这可能是竞争条件。您确实应该在MRESOURCES提出问题。