如何为 mvn 修复“java.lang.ClassNotFoundException: org.apache.maven.model.io.xpp3.MavenXpp3WriterEx”帮助评估

Question

我正在尝试使用以下命令在我的 pom.xml 中获取模块。这一直工作到昨天。 Maven artfiact 存储在 artifactory 中，并且正在使用 .m2/settings.xml 连接到中心并下载工件。我确信jenkins和artifactory没有交互但突然盯着看失败

我尝试将 M2_HOME/MAVEN_HOME 更改为 M3_home。 尝试删除 .m2/repository 并运行 mvn 命令重新下载

Apache Maven 3.5.3 (3383c37e1f9e9b3bc3df5050c29c8aff9f295297; 2018-02-24T14:49:05-05:00) Maven 主页：/Users/jenkins/Downloads/apache-maven-3.5.3 Java 版本：1.8.0_172，供应商：甲骨文公司 Java 主页：/Library/Java/JavaVirtualMachines/jdk1.8.0_172.jdk/Contents/Home/jre 默认语言环境：en_US，平台编码：UTF-8 操作系统名称：“mac os x”，版本：“10.14.2”，arch：“x86_64”，系列：“mac”

mvn help:evaluate -Dexpression=project.modules -B

Expected

[Info] Downloading ....
[Info] Downloaded ....
[Info]....
[Info]....
[Info]....
[Info]....
<modules>
  <module>example-mod1</module>
  <module>example-mod2</module>
  <module>example-mod3</module>
</modules>
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 31.185 s
[INFO] Finished at: 2019-04-17T16:52:52-04:00
[INFO] ------------------------------------------------------------------------

Actual

[Info] Downloading ....
[Info] Downloaded ....
[Info]....
[Info]....
[Info]....
[Info]....
[ERROR]
java.lang.ClassNotFoundException: org.apache.maven.model.io.xpp3.MavenXpp3WriterEx
    at org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass (SelfFirstStrategy.java:50)
    at org.codehaus.plexus.classworlds.realm.ClassRealm.unsynchronizedLoadClass (ClassRealm.java:271)
    at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass (ClassRealm.java:247)
    at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass (ClassRealm.java:239)
    at java.lang.Class.forName0 (Native Method)
    at java.lang.Class.forName (Class.java:348)
    at org.apache.commons.lang3.ClassUtils.getClass (ClassUtils.java:993)
    at org.apache.commons.lang3.ClassUtils.getClass (ClassUtils.java:1059)
    at org.apache.commons.lang3.ClassUtils.getClass (ClassUtils.java:1042)
    at org.apache.maven.plugins.help.EvaluateMojo.addAlias (EvaluateMojo.java:542)
    at org.apache.maven.plugins.help.EvaluateMojo.addAlias (EvaluateMojo.java:491)
    at org.apache.maven.plugins.help.EvaluateMojo.getXStream (EvaluateMojo.java:455)
    at org.apache.maven.plugins.help.EvaluateMojo.toXML (EvaluateMojo.java:420)
    at org.apache.maven.plugins.help.EvaluateMojo.handleResponse (EvaluateMojo.java:381)
    at org.apache.maven.plugins.help.EvaluateMojo.execute (EvaluateMojo.java:214)
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:137)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:208)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:154)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:146)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:117)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:81)
    at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build (SingleThreadedBuilder.java:56)
    at org.apache.maven.lifecycle.internal.LifecycleStarter.execute (LifecycleStarter.java:128)
    at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:305)
    at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:192)
    at org.apache.maven.DefaultMaven.execute (DefaultMaven.java:105)
    at org.apache.maven.cli.MavenCli.execute (MavenCli.java:956)
    at org.apache.maven.cli.MavenCli.doMain (MavenCli.java:290)
    at org.apache.maven.cli.MavenCli.main (MavenCli.java:194)
    at sun.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke (NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke (Method.java:498)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced (Launcher.java:289)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch (Launcher.java:229)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode (Launcher.java:415)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main (Launcher.java:356)
[INFO]
<strings>
  <string>example-mod1</string>
  <string>example-mod2</string>
  <string>example-mod3</string>
</strings>
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 31.185 s
[INFO] Finished at: 2019-04-17T16:52:52-04:00
[INFO] ------------------------------------------------------------------------

Answer 1

MavenXPP3writerEx 类似乎仅在 Maven 3.6.1 API 中可用。

如果您使用的是 Maven 3.3.9 或 3.6.1 之前的任何版本，那么您将收到以下消息：您尝试使用最新版本的 maven-help-plugin（旨在与 Maven 3.6 兼容.1)，但与早期版本不兼容。

然后，要使用兼容版本，您必须限制 maven-help-plugin 的版本，以便正确使用它。为此，请在您的 POM 中定义一个 pluginManagement 部分，并使用版本 3.1.0（适用于 Maven 3.3.9）声明 maven-help-plugin。 我没有尝试使用其他 Maven 配置。