java.lang.ClassCastException

public class ipSort {
public static class Map extends Mapper{
//将输入文件转换成的形式
private final static IntWritable ipNum = new IntWritable();
private Text ipAdd = new Text();
public void map(LongWritable key, IntWritable value, Context context)
throws IOException, InterruptedException{
//把每一行转成字符串
String line = value.toString();
// 分割每一行

StringTokenizer token = new StringTokenizer(line);
//solve every line
while(token.hasMoreElements()){
//divided by blank
StringTokenizer tokenLine = new StringTokenizer(token.nextToken());
ipAdd.set(token.nextToken().trim());
ipNum.set(Integer.valueOf(token.nextToken().trim()));
context.write(ipNum,new Text(ipAdd));

            }
        }
    }
    public static class Reduce extends Reducer<IntWritable, Text, Text, IntWritable>{
        //把Map阶段的输出结果颠倒；
        private Text result = new Text();
        public void reduce(IntWritable key,Iterable<Text> values, Context context) 
                throws IOException, InterruptedException{
            for(Text val : values){
                result.set(val.toString());
                context.write(new Text(result),key);
            }
        }
    }
    public static class IntKeyDescComparator extends WritableComparator{
        protected IntKeyDescComparator(){
            super(IntWritable.class,true);
        }
        public int compare(WritableComparable a, WritableComparable b){
            return super.compare(a, b);

        }
    }
    public static void main(String args[]) 
            throws IOException, ClassNotFoundException, InterruptedException{
        System.setProperty("hadoop.home.dir", "C:\\Users\\lenovo\\Desktop\\hadoop-2.6.0\\hadoop-2.6.0");
        Configuration conf = new Configuration();
        conf.set("mapred.job.tracker",  "192.168.142.138");

        Job job = new Job(conf,"ipSort");
        job.setJarByClass(ipSort.class);
        job.setSortComparatorClass(IntKeyDescComparator.class);

        job.setMapperClass(Map.class);
        job.setReducerClass(Reduce.class);

        job.setOutputKeyClass(IntWritable.class);
        job.setOutputValueClass(Text.class);

        FileInputFormat.addInputPath(job, new Path("hdfs://10.170.54.193:9000/input"));
        FileOutputFormat.setOutputPath(job, new Path("hdfs://10.170.54.193:9000/output"));
        System.exit(job.waitForCompletion(true)?0:1);

    }
            运行时出现问题Caused by: java.lang.ClassCastException: org.apache.hadoop.io.Text cannot be cast to org.apache.hadoop.io.IntWritable，但是找不到哪里类型转换错误了

http://stackoverflow.com/questions/11784729/hadoop-java-lang-classcastexception-org-apache-hadoop-io-longwritable-cannot

public void reduce(IntWritable key,Iterable<Text> values, Context context) 
                throws IOException, InterruptedException{
            for(Text val : values){
                result.set(val.toString());
                context.write(new Text(result),key);
            }
        }

讀代碼感覺可能是 context.write(new Text(result),key); 出錯了。
正確的是不是：context.write(key，new Text(result));

package ipmapreduce;

import java.io.IOException;
import java.util.StringTokenizer;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.WritableComparable;
import org.apache.hadoop.io.WritableComparator;
import org.apache.hadoop.mapred.TextInputFormat;
import org.apache.hadoop.mapred.TextOutputFormat;
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 ipSort {
public static class Map extends Mapper{
//将输入文件转换成的形式
private final static IntWritable ipNum = new IntWritable(1);
private Text ipAdd = new Text();
public void map(LongWritable key, Text value, Context context)
throws IOException, InterruptedException{

            String line = value.toString();
            // 分割每一行                          
            StringTokenizer  token = new StringTokenizer(line);
            //solve every line
            while(token.hasMoreElements()){
                //divided by blank
                //StringTokenizer tokenLine = new StringTokenizer(token.nextToken());

                ipAdd.set(token.nextToken().trim());
                ipNum.set(Integer.valueOf(token.nextToken().trim()));           
                context.write(ipNum,ipAdd);

            }
        }
    }
    public static class Reduce extends Reducer<IntWritable, Text, Text, IntWritable>{
        //把Map阶段的输出结果颠倒；
        private Text result = new Text();
        public void reduce(IntWritable key,Iterable<Text> values, Context context) 
                throws IOException, InterruptedException{
            for(Text val : values){
                result.set(val.toString());
                context.write(result,key);
            }
        }
    }

    public static class IntKeyDescComparator extends WritableComparator{
        protected IntKeyDescComparator(){
            super(IntWritable.class,true);
        }
        public int compare(WritableComparable a, WritableComparable b){
            return super.compare(a, b);

        }
    }

    public static void main(String args[]) 
            throws IOException, ClassNotFoundException, InterruptedException{
        System.setProperty("hadoop.home.dir", "C:\\Users\\lenovo\\Desktop\\hadoop-2.6.0\\hadoop-2.6.0");
        Configuration conf = new Configuration();
        conf.set("mapred.job.tracker",  "192.168.142.138");

        Job job = new Job(conf,"ipSort");
        job.setJarByClass(ipSort.class);
        job.setSortComparatorClass(IntKeyDescComparator.class);

        job.setMapperClass(Map.class);
        job.setReducerClass(Reduce.class);

        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(IntWritable.class);
        //job.setInputFormatClass(TextInputFormat.class);
        //job.setOutputFormatClass(TextOutputFormat.class);


        FileInputFormat.addInputPath(job, new Path("hdfs://10.170.54.193:9000/input"));
        FileOutputFormat.setOutputPath(job, new Path("hdfs://10.170.54.193:9000/output"));
        System.exit(job.waitForCompletion(true)?0:1);

    }

}