我正在尝试在Hadoop2.2上使用mahout0.9库执行XML解析的mapreduce作业。但我收到以下错误:14/02/2416:03:02INFOmapreduce.Job:TaskId:attempt_1393235568433_0004_m_000000_0,Status:FAILEDError:Foundinterfaceorg.apache.hadoop.mapreduce.TaskAttemptContext,butclasswasexpected14/02/2416:03:12INFOmapreduce.Job:TaskId:attempt_139323556843