正在创建用于在Hadoop1.2.1上运行MapReduce的jar

Question

我是Hadoop的新手，刚刚在我的Mac笔记本电脑（Mavericks）上安装了Hadoop1.2.1。然后，我在IntelliJ IDEA中创建了一个简单的WordCount项目，并能够在伪文本文件上运行代码。我在成功创建一个jar文件时遇到了问题，该文件将通过IDE复制我的执行。我得到以下错误：

java -jar ./out/artifacts/WordCount_jar/WordCount.jar test.txt out [19:35:21]
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/commons/logging/LogFactory
    at org.apache.hadoop.conf.Configuration.<clinit>(Configuration.java:146)
    at neu.cs.parallelprogramming.WordCount.main(WordCount.java:48)
Caused by: java.lang.ClassNotFoundException: org.apache.commons.logging.LogFactory
    at java.net.URLClassLoader$1.run(URLClassLoader.java:372)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 2 more
FAIL: 1

有人能告诉我我缺了什么吗？

Answer 1

我想您必须指定您的类（实现Map/Reduce函数）。例如，$ java -jar ./WordCount.jar classWordCount input.txt output或$ hadoop jar yourprogram.jar **yourclass** inputpath outputpath