Finding the number of palindromes in a text corpus using Hadoop

Palindrome.java

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.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;
import org.apache.hadoop.util.GenericOptionsParser;

public class Palindrome {
    public static class PalindromeMapper
      extends Mapper<Object, Text, Text, IntWritable> {
      
      public void map(Object key, Text value, Context context)
        throws IOException, InterruptedException {
        // Format: K1,V1,K2,V2
        

        // So key here probably is the byte offset
        // Value is the line
        // Context is the stream to which you will write
        // Loads of customizations are possible, to get the
        //  key-value format that you want.
        
        Text word = new Text();
        IntWritable one = new IntWritable(1);

        StringTokenizer tokens = new StringTokenizer(value.toString());
        while(tokens.hasMoreTokens()) {
            String token = tokens.nextToken();

	        // Check if palindrome
            boolean isPalindrome = true;

            for(int i = 0; i < token.length(); i++)
                if(token.charAt(i) != token.charAt(token.length()-i-1))
                {
                    isPalindrome = false;
                    break;
                }

	        if(isPalindrome)
	        {
		        word.set(token);
	            context.write(word, one);
            }
	  
        }
        
      }
     }   


      public static class PalindromeReducer
        extends Reducer<Text,IntWritable,Text,IntWritable> {
        
        private IntWritable result = new IntWritable();
        
        public void reduce(Text key, Iterable<IntWritable> values, Context context)
          throws IOException, InterruptedException {
          
          int sum = 0;
          for(IntWritable val : values) {
            sum += val.get();
          }
          
          result.set(sum);
          context.write(key, result);
        }

      }
      
      public static void main(String[] args) throws Exception {
      
        Configuration conf = new Configuration();
        
        Job job = new Job(conf, "palindrome");
        job.setJarByClass(Palindrome.class);
        job.setMapperClass(PalindromeMapper.class);
        job.setReducerClass(PalindromeReducer.class);
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(IntWritable.class);
        FileInputFormat.addInputPath(job, new Path(args[0]));
        FileOutputFormat.setOutputPath(job, new Path(args[1]));
        System.exit(job.waitForCompletion(true) ? 0 : 1);
      }
      
   
   
}

this code doesnot give correct palindrome output,it shows the word is palindrome even if only first and last letters matches ..pls help