我遇到这个问题好几天了。当我使用hadoop1.2时，它工作正常。当我转向 hadoop2.x（hadoop2.4 或 hadoop2.5.2）时，我遇到了这个问题：
java.lang.Exception: java.lang.IncompatibleClassChangeError: Found interface org.apache.hadoop.mapreduce.TaskAttemptContext, but class was expected
at org.apache.hadoop.mapred.LocalJobRunner$Job.runTasks(LocalJobRunner.java:462)
at org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:522)
Caused by: java.lang.IncompatibleClassChangeError: Found interface org.apache.hadoop.mapreduce.TaskAttemptContext, but class was expected
at org.apache.gora.mapreduce.GoraOutputFormat.getRecordWriter(GoraOutputFormat.java:83)
at org.apache.hadoop.mapred.MapTask$NewDirectOutputCollector.<init>(MapTask.java:624)
at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:744)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:340)
at org.apache.hadoop.mapred.LocalJobRunner$Job$MapTaskRunnable.run(LocalJobRunner.java:243)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
at java.util.concurrent.FutureTask.run(FutureTask.java:262)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:744)
我发现我在使用hadoop2.x的时候ivy.xml，会hadoop-core-1.0.1.jar自动产生一个，好像是受gora的依赖影响。排除hadoop-core-*后，就会出现这个问题！我还手动更新了 jar 文件avro-mapre-1.7.6.jar，avro-mapred-1.7.6-hadoop2.jar不幸的是没有任何变化！任何想法将不胜感激，谢谢！