IDEA里运行代码时出现Caused by: java.lang.ClassNotFoundException: org.apache.log4j.Logger的解决办法（图文详解）

　　不多说，直接上干货！

问题详情

　　运行出现log4j的问题

"C:\Program Files\Java\jdk1.8.0_66\bin\java" -Didea.launcher.port= "-Didea.launcher.bin.path=D:\SoftWare\IntelliJ IDEA\IntelliJ IDEA Community Edition 2016.1.4\bin" -Dfile.encoding=UTF- -classpath "C:\Program Files\Java\jdk1.8.0_66\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_66\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.8.0_66\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.8.0_66\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\jdk1.8.0_66\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.8.0_66\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.8.0_66\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\jdk1.8.0_66\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.8.0_66\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_66\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.8.0_66\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.8.0_66\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.8.0_66\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\jdk1.8.0_66\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.8.0_66\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.8.0_66\jre\lib\jce.jar;C:\Program Files\Java\jdk1.8.0_66\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.8.0_66\jre\lib\jfxswt.jar;C:\Program Files\Java\jdk1.8.0_66\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.8.0_66\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.8.0_66\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.8.0_66\jre\lib\resources.jar;C:\Program Files\Java\jdk1.8.0_66\jre\lib\rt.jar;D:\Code\IntelliJIDEACode\HadoopSparkMllibAction\target\classes;D:\SoftWare\maven\repository\org\scala-lang\scala-library\2.10.4\scala-library-2.10.4.jar;C:\Program Files\Java\jdk1.8.0_66\jre\..\lib\tools.jar;D:\SoftWare\IntelliJ IDEA\IntelliJ IDEA Community Edition 2016.1.4\lib\idea_rt.jar" com.intellij.rt.execution.application.AppMain zhouls.bigdata.chapter10.RunWordCount
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/log4j/Logger
    at zhouls.bigdata.chapter10.RunWordCount$.main(RunWordCount.scala:)
    at zhouls.bigdata.chapter10.RunWordCount.main(RunWordCount.scala)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:)
    at java.lang.reflect.Method.invoke(Method.java:)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:)
Caused by: java.lang.ClassNotFoundException: org.apache.log4j.Logger
    at java.net.URLClassLoader.findClass(URLClassLoader.java:)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:)
    ...  more

Process finished with exit code 

解决办法

　　在项目的pom.xml里添加如下的配置信息

<dependency>
      <groupId>log4j</groupId>
      <artifactId>log4j</artifactId>
      <version>1.2.</version>
      <scope>compile</scope>
 </dependency>

　　当然，这版本，大家也可以选择个最新的稳定版本，我这里仅仅是个参考。