hadoop wrong key class: class org.apache.hadoop.io.Tex

java.io.IOException: wrong key class: class org.apache.hadoop.io.Text is not class com.sogou.web.selector.updana.wapPc.test.TextPair
	at org.apache.hadoop.mapred.IFile$Writer.append(IFile.java:172)
	at org.apache.hadoop.mapred.Task$CombineOutputCollector.collect(Task.java:1119)
	at org.apache.hadoop.mapred.Task$NewCombinerRunner$OutputConverter.write(Task.java:1440)
	at org.apache.hadoop.mapreduce.TaskInputOutputContext.write(TaskInputOutputContext.java:80)
	at com.sogou.web.selector.updana.wapPc.WapPcReducer.reduce(WapPcReducer.java:28)
	at com.sogou.web.selector.updana.wapPc.WapPcReducer.reduce(WapPcReducer.java:1)
	at org.apache.hadoop.mapreduce.Reducer.run(Reducer.java:195)
	at org.apache.hadoop.mapred.Task$NewCombinerRunner.combine(Task.java:1461)
	at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.sortAndSpill(MapTask.java:1334)
	at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.flush(MapTask.java:1198)
	at org.apache.hadoop.mapred.MapTask$NewOutputCollector.close(MapTask.java:608)
	at org.apache.had
java.io.IOException: wrong key class: class org.apache.hadoop.io.Text is not class com.sogou.web.selector.updana.wapPc.test.TextPair
	at org.apache.hadoop.mapred.IFile$Writer.append(IFile.java:172)
	at org.apache.hadoop.mapred.Task$CombineOutputCollector.collect(Task.java:1119)
	at org.apache.hadoop.mapred.Task$NewCombinerRunner$OutputConverter.write(Task.java:1440)
	at org.apache.hadoop.mapreduce.TaskInputOutputContext.write(TaskInputOutputContext.java:80)
	at com.sogou.web.selector.updana.wapPc.WapPcReducer.reduce(WapPcReducer.java:28)
	at com.sogou.web.selector.updana.wapPc.WapPcReducer.reduce(WapPcReducer.java:1)
	at org.apache.hadoop.mapreduce.Reducer.run(Reducer.java:195)
	at org.apache.hadoop.mapred.Task$NewCombinerRunner.combine(Task.java:1461)
	at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.sortAndSpill(MapTask.java:1334)
	at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.flush(MapTask.java:1198)
	at org.apache.hadoop.mapred.MapTask$NewOutputCollector.close(MapTask.java:608)
	at org.apache.had
java.io.IOException: wrong key class: class org.apache.hadoop.io.Text is not class com.sogou.web.selector.updana.wapPc.test.TextPair
	at org.apache.hadoop.mapred.IFile$Writer.append(IFile.java:172)
	at org.apache.hadoop.mapred.Task$CombineOutputCollector.collect(Task.java:1119)
	at org.apache.hadoop.mapred.Task$NewCombinerRunner$OutputConverter.write(Task.java:1440)
	at org.apache.hadoop.mapreduce.TaskInputOutputContext.write(TaskInputOutputContext.java:80)
	at com.sogou.web.selector.updana.wapPc.WapPcReducer.reduce(WapPcReducer.java:28)
	at com.sogou.web.selector.updana.wapPc.WapPcReducer.reduce(WapPcReducer.java:1)
	at org.apache.hadoop.mapreduce.Reducer.run(Reducer.java:195)
	at org.apache.hadoop.mapred.Task$NewCombinerRunner.combine(Task.java:1461)
	at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.sortAndSpill(MapTask.java:1334)
	at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.flush(MapTask.java:1198)
	at org.apache.hadoop.mapred.MapTask$NewOutputCollector.close(MapTask.java:608)
	at org.apache.had
java.io.IOException: wrong key class: class org.apache.hadoop.io.Text is not class com.sogou.web.selector.updana.wapPc.test.TextPair
	at org.apache.hadoop.mapred.IFile$Writer.append(IFile.java:172)
	at org.apache.hadoop.mapred.Task$CombineOutputCollector.collect(Task.java:1119)
	at org.apache.hadoop.mapred.Task$NewCombinerRunner$OutputConverter.write(Task.java:1440)
	at org.apache.hadoop.mapreduce.TaskInputOutputContext.write(TaskInputOutputContext.java:80)
	at com.sogou.web.selector.updana.wapPc.WapPcReducer.reduce(WapPcReducer.java:28)
	at com.sogou.web.selector.updana.wapPc.WapPcReducer.reduce(WapPcReducer.java:1)
	at org.apache.hadoop.mapreduce.Reducer.run(Reducer.java:195)
	at org.apache.hadoop.mapred.Task$NewCombinerRunner.combine(Task.java:1461)
	at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.sortAndSpill(MapTask.java:1334)
	at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.flush(MapTask.java:1198)
	at org.apache.hadoop.mapred.MapTask$NewOutputCollector.close(MapTask.java:608)
	at org.apache.had
修改方法：去掉combiner

//设置combiner
//job.setCombinerClass(Reducer.class);

去掉上述代码就行了，原因应该是设置的Reducer cannot be same due to inconsistency in the output key and value types.