Maven:将本地 log4j jar 设置为依赖项时出错

Question

出于某些技术原因，我必须在pom文件中将log4j作为本地jar包含在pom文件中。我试过：

<dependency>
  <groupId>log4j</groupId>
  <artifactId>apache-log4j-extras</artifactId>
  <scope>system</scope>
  <systemPath>path_to_jar/apache-log4j-extras-1.1.jar</systemPath>
</dependency>

带

和不带：

  <version>1.1</version>

无论哪种方式，我都会Failed to validate POM for project得到神秘的消息，而不参考具体的失败原因。当从 maven 存储库获取 log4j 时，这运行良好。

[INFO] Trace
org.apache.maven.reactor.MavenExecutionException: Failed to validate POM for project ... at ...hudson_checkout/vespa_qa/pom_local.xml
    at org.apache.maven.DefaultMaven.getProjects(DefaultMaven.java:404)
    at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:272)
    at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:138)
    at org.apache.maven.cli.MavenCli.main(MavenCli.java:362)
    at org.apache.maven.cli.compat.CompatibleMain.main(CompatibleMain.java:60)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    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)
Caused by: org.apache.maven.project.InvalidProjectModelException: Failed to validate POM for project ... at /....xml
    at org.apache.maven.project.DefaultMavenProjectBuilder.processProjectLogic(DefaultMavenProjectBuilder.java:1077)
    at org.apache.maven.project.DefaultMavenProjectBuilder.buildInternal(DefaultMavenProjectBuilder.java:880)
    at org.apache.maven.project.DefaultMavenProjectBuilder.buildFromSourceFileInternal(DefaultMavenProjectBuilder.java:508)
    at org.apache.maven.project.DefaultMavenProjectBuilder.build(DefaultMavenProjectBuilder.java:200)
    at org.apache.maven.DefaultMaven.getProject(DefaultMaven.java:604)
    at org.apache.maven.DefaultMaven.collectProjects(DefaultMaven.java:487)
    at org.apache.maven.DefaultMaven.getProjects(DefaultMaven.java:391)
    ... 12 more
[INFO] ------------------------------------------------------------------------
[INFO] Total time: < 1 second

jar 位于指定的文件夹中，并具有读取权限。知道这个依赖关系有什么问题吗？

Answer 1

我用"-X"执行了maven，并得到了一条更有用的消息：

[0]  'dependencies.dependency.version' is missing for log4j:apache-log4j-extras:jar

所以我再次添加了版本。项目仍然失败，并显示奇怪的错误消息。我进一步搜索，发现从系统路径获取 og4j 的常用方法需要 tis 组 id：

<groupId>org.apache.log4j</groupId>

而不是：

<groupId>log4j</groupId>