mapreduce 实现单词的个数统计

数据形式：
第一行 ABCDE
第二行 CDEF

利用mapreduce统计出现单词的个数（ABCDEF一共6个单词）

这不需要mapreduce 直接map输出就可以了，reduce用不到吧。

import java.io.*;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;

public class WordCount
{
    public static class WordCountMapper
    extends Mapper<Object,Text,Text,IntWritable>
   {
       private final static IntWritable one = new IntWritable(1);
       private Text word = new Text();
       public void map(Object key,Text value,Context context)  
        throws IOException, InterruptedException {
String[] words = value.toString().split(",");
 for (String str: words)
           {
                         //去除空格，防止越界
                 String ss=str.replace(" ","");
                   for(int i=0;i<ss.length();i++){
                        word.set(str.substring(i,i+1));  
                        context.write(word,one);
                   }
            }
    }
}
 public static class WordCountReducer extends Reducer<Text,IntWritable,Text,IntWritable> {
  public void reduce(Text key,Iterable<IntWritable> values,Context context) throws IOException, InterruptedException {
          int total=0;
        for (IntWritable val : values){
            total += val.get();
         }
IntWritable sum = new IntWritable(total);
context.write(key, sum);
       }   
     }
//INPUT_PATH：文件在hdfs上的路径
private static final String INPUT_PATH = "/mr.txt";
//OUTPUT_PATH：文件输出路径
private static final String OUTPUT_PATH = "/mr/out/";
public static void main (String[] args) throws Exception{
Configuration conf = new Configuration(); 
conf.set("mapred.jar","wc.jar");
Job job = new Job(conf, "word count");
job.setJarByClass(WordCount.class);
job.setMapperClass(WordCountMapper.class);
job.setReducerClass(WordCountReducer.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(IntWritable.class);
FileInputFormat.setInputPaths(job, INPUT_PATH);
FileOutputFormat.setOutputPath(job, new Path(OUTPUT_PATH));
 }
}