线程"main"中的异常java.lang.NoClassDefFoundError:org/apache/hadoop/util/Tool

Question

I get below error when i package (jar) and run my defaulthadoopjob. 

Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/hadoop/util/Tool
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:615)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
    at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
    at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
Caused by: java.lang.ClassNotFoundException: org.apache.hadoop.util.Tool
    at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
    ... 12 more
Could not find the main class: DefaultHadoopJobDriver. Program will exit.


Commands used to build Jar. 

# jar -cvf dhj.jar 
# hadoop -jar dhj.jar DefaultHadoopJobDriver

The above command gave me error "Failed to load Main-Class manifest attribute from dhj.jar"

rebuilt jar with manifest using below command

jar -cvfe dhj.jar DefaultHadoopJobDriver.
hadoop -jar dhj.jar DefaultHadoopJobDriver - 这返回了我上面报告的原始错误消息.

我的Hadoop作业有单个类"DefaultHoopJobDrive",它扩展了Configures并实现了Tool,并且运行方法只作为Job创建和输入路径,outpurpath集的代码.Aslo Im使用新的API.

I'm running hadoop 1.2.1 and the Job works fine from eclipse.

This might be something to do with the classpath. Please help.

Answer 1

为了执行那个罐子,你不必给予hadoop -jar.命令是这样的:

 hadoop jar <jar> [mainClass] args...

如果这个jar再次获得java.lang.ClassNotFoundException异常,那么你可以使用:

hadoop classpath

命令查看hadoop-core-1.2.1.jarhadoop安装类路径中是否存在？

仅供参考,如果此列表中没有,您必须将此jar添加到hadoop lib目录中.