[root@h1 ~]# hadoop jar W1.jar hdfs://h1:9000/hello hdfs://h1:9000/cmd
Exception in thread "main" java.lang.ClassNotFoundException: hdfs://h1:9000/hello
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:247)
at org.apache.hadoop.util.RunJar.main(RunJar.java:149)
找不到main方法,由于导出jar包时没有指定出口类。