map减少字数例子

Question

我想用map reduce运行一个简单的字数统计示例.但我有这个问题,不知道如何解决它.

Exception in thread "main" java.lang.VerifyError: Bad type on operand stack
Exception Details:
  Location:
    org/apache/hadoop/mapred/JobTrackerInstrumentation.create(Lorg/apache/hadoop/mapred/JobTracker;Lorg/apache/hadoop/mapred/JobConf;)Lorg/apache/hadoop/mapred/JobTrackerInstrumentation; @5: invokestatic
  Reason:
    Type 'org/apache/hadoop/metrics2/lib/DefaultMetricsSystem' (current frame, stack[2]) is not assignable to 'org/apache/hadoop/metrics2/MetricsSystem'
  Current Frame:
    bci: @5
    flags: { }
    locals: { 'org/apache/hadoop/mapred/JobTracker', 'org/apache/hadoop/mapred/JobConf' }
    stack: { 'org/apache/hadoop/mapred/JobTracker', 'org/apache/hadoop/mapred/JobConf', 'org/apache/hadoop/metrics2/lib/DefaultMetricsSystem' }
  Bytecode:
    0000000: 2a2b b200 03b8 0004 b0 

Answer 1

我有同样的问题,它通过删除Maven中的一些不需要的引用(hadoop-common和hadoop-hdfs)得到解决.我正在使用Windows的hadoop 2.2.0,连接到Linux hadoop单节点集群.