hadoop example---异常记录（待解决）

用的是hadoop.0.20.2,在命令行执行如下命令：

 bin/hadoop jar hadoop-*-examples.jar aggregatewordcount wordcount aggregatewordcount_output 1 textinputformat

在执行任务的时候抛出java.lang.RuntimeException:

11/09/29 15:56:21 INFO mapred.FileInputFormat: Total input paths to process : 2
11/09/29 15:56:21 INFO mapred.JobClient: Running job: job_201109291335_0013
11/09/29 15:56:22 INFO mapred.JobClient:  map 0% reduce 0%
11/09/29 15:56:33 INFO mapred.JobClient: Task Id : attempt_201109291335_0013_m_000000_0, Status : FAILED
java.lang.RuntimeException: Error in configuring object
at org.apache.hadoop.util.ReflectionUtils.setJobConf(ReflectionUtils.java:93)
at org.apache.hadoop.util.ReflectionUtils.setConf(ReflectionUtils.java:64)
at org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:117)
at org.apache.hadoop.mapred.MapTask.runOldMapper(MapTask.java:354)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:307)
at org.apache.hadoop.mapred.Child.main(Child.java:170)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at org.apache.hadoop.util.ReflectionUtils.setJobConf(ReflectionUtils.java:88)
... 5 more
Caused by: java.lang.RuntimeException: Error in configuring object
at org.apache.hadoop.util.ReflectionUtils.setJobConf(ReflectionUtils.java:93)
at org.apache.hadoop.util.ReflectionUtils.setConf(ReflectionUtils.java:64)
at org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:117)
at org.apache.hadoop.mapred.MapRunner.configure(MapRunner.java:34)
... 10 more
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at org.apache.hadoop.util.ReflectionUtils.setJobConf(ReflectionUtils.java:88)
... 13 more
Caused by: java.lang.RuntimeException: java.lang.ClassNotFoundException: org.apache.hadoop.examples.AggregateWordCount$WordCountPlugInClass
at org.apache.hadoop.mapred.lib.aggregate.UserDefinedValueAggregatorDescriptor.createInstance(UserDefinedValueAggregatorDescriptor.java:57)
at org.apache.hadoop.mapred.lib.aggregate.UserDefinedValueAggregatorDescriptor.createAggregator(UserDefinedValueAggregatorDescriptor.java:64)
at org.apache.hadoop.mapred.lib.aggregate.UserDefinedValueAggregatorDescriptor.<init>(UserDefinedValueAggregatorDescriptor.java:76)
at org.apache.hadoop.mapred.lib.aggregate.ValueAggregatorJobBase.getValueAggregatorDescriptor(ValueAggregatorJobBase.java:54)
at org.apache.hadoop.mapred.lib.aggregate.ValueAggregatorJobBase.getAggregatorDescriptors(ValueAggregatorJobBase.java:65)
at org.apache.hadoop.mapred.lib.aggregate.ValueAggregatorJobBase.initializeMySpec(ValueAggregatorJobBase.java:74)
at org.apache.hadoop.mapred.lib.aggregate.ValueAggregatorJobBase.configure(ValueAggregatorJobBase.java:42)
... 18 more
Caused by: java.lang.ClassNotFoundException: org.apache.hadoop.examples.AggregateWordCount$WordCountPlugInClass
at java.net.URLClassLoader$1.run(URLClassLoader.java:217)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
at java.lang.ClassLoader.loadClass(ClassLoader.java:321)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)
at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:264)
at org.apache.hadoop.mapred.lib.aggregate.UserDefinedValueAggregatorDescriptor.createInstance(UserDefinedValueAggregatorDescriptor.java:52)
... 24 more

可以看出是因为找不到内部类class造成的，不过应该出现这个异常的。