关于MapReduce

坑:

Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/hadoop/util/StopWatch
    at org.apache.hadoop.mapred.FileInputFormat.getSplits(FileInputFormat.java:314)

啊,还是最爱StackOverFlow啊!!!
一直报上面错误,找了半天原因,在sof上看到是版本原因,果然,更换pom.xml版本后,解决了问题!
I solved the problem , actually there was version incompetency so i change hadoop-client 2.6.0 to 2.7.0

<dependency>
    <groupId>org.apache.hadoop</groupId>
    <artifactId>hadoop-common</artifactId>
    <version>2.7.2</version>
</dependency>