我是hadoop新手，遇到过这个问题。我正在尝试将默认文本、整型值的大小写改为文本、文本。我想Map文本，intwritable，然后在reducer中我想有2个计数器，这取决于值是什么，然后将这2个计数器写入收集器的文本中。

public class WordCountMapper extends MapReduceBase
    implements Mapper<LongWritable, Text, Text, IntWritable> {

  private final IntWritable one = new IntWritable(1);
  private Text word = new Text();

  public void map(LongWritable key, Text value, OutputCollector<Text, IntWritable>
        output, Reporter reporter) throws IOException {

    String line = value.toString();
    String[] words = line.split(",");
    String[] date = words[2].split(" ");
      word.set(date[0]+" "+date[1]+" "+date[2]);
      if(words[0].contains("0"))
          one.set(0);
      else
          one.set(4);
      output.collect(word, one);

  }
}

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public class WordCountReducer extends MapReduceBase
    implements Reducer<Text, IntWritable, Text, Text> {

  public void reduce(Text key,Iterator<IntWritable> values,
                  OutputCollector<Text, Text> output,
                  Reporter reporter) throws IOException {

    int sad = 0;
    int happy = 0;
    while (values.hasNext()) {
      IntWritable value = (IntWritable) values.next();
      if(value.get() == 0)
          sad++; // process value
      else
          happy++;
    }

    output.collect(key, new Text("sad:"+sad+", happy:"+happy));
  }
}
---------------------------------------------------------------------------------

public class WordCount {

  public static void main(String[] args) {
    JobClient client = new JobClient();
    JobConf conf = new JobConf(WordCount.class);

    // specify output types
    conf.setOutputKeyClass(Text.class);
    conf.setOutputValueClass(IntWritable.class);

    // specify input and output dirs
    FileInputFormat.addInputPath(conf, new Path("input"));
    FileOutputFormat.setOutputPath(conf, new Path("output"));

    // specify a mapper
    conf.setMapperClass(WordCountMapper.class);

    // specify a reducer
    conf.setReducerClass(WordCountReducer.class);
    conf.setCombinerClass(WordCountReducer.class);

    client.setConf(conf);
    try {
      JobClient.runJob(conf);
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
}

我得到这个错误：
14/12/10 18:11:01 info mapred.jobclient:任务id:尝试\u 201412100143 \u 0008 \u m \u0000000，状态：failed java.io.ioexception:溢出失败，位于org.apache.hadoop.mapred.maptask$mapoutputbuffer.collect（maptask）。java:425)在wordcountmapper.map（wordcountmapper。java:31)在wordcountmapper.map（wordcountmapper。java:1)在org.apache.hadoop.mapred.maprunner.run（maprunner。java:47)在org.apache.hadoop.mapred.maptask.run（maptask。java:227)在org.apache.hadoop.mapred.tasktracker$child.main（tasktracker。java:2209)原因：java.io.ioexception:错误的值class:class org.apache.hadoop.io.text不是class org.apache.hadoop.io.intwriteable at org.apache.hadoop.mapred.ifile$writer.append（ifile）。java:143)在org.apache.hadoop.mapred.task$combineoutputcollector.collect（task。java:626)在wordcountreducer.reduce（wordcountreducer。java:29)在wordcountreducer.reduce（wordcountreducer。java:1)在org.apache.hadoop.mapred.maptask$mapoutputbuffer.combineandspill（maptask。java:904)在org.apache.hadoop.mapred.maptask$mapoutputbuffer.sortandspill（maptask。java:785)在org.apache.hadoop.mapred.maptask$mapoutputbuffer.access$1600（maptask。java:286)在org.apache.hadoop.mapred.maptask$mapoutputbuffer$spillthread.run（maptask。java:712)
在此之后，错误会重复多次。有人能解释一下为什么会发生这种错误吗？我搜索了与此类似的错误，但找到的都是Map器和还原器的不匹配键值类型，但正如我看到的，Map器和还原器的键值类型是匹配的。先谢谢你。