Implement Conflation Algorithm using File Handling in Java

package com.prac.prac;  
 import java.io.BufferedReader;  
 import java.io.FileNotFoundException;  
 import java.io.FileReader;  
 import java.io.IOException;  
 import java.io.InputStreamReader;  
 import java.util.ArrayList;  
 import java.util.StringTokenizer;  
 import java.util.regex.Matcher;  
 import java.util.regex.Pattern;  
 public class conflation {  
      /**  
       * @param args  
       */  
      public static void main(String[] args) {  
           InputStreamReader st = new InputStreamReader(System.in);  
           BufferedReader buff = new BufferedReader(st);  
           String fname="";  
           System.out.println("Enter File Name :");  
           try {  
                fname = buff.readLine();  
           } catch (IOException e) {  
                // TODO Auto-generated catch block  
                e.printStackTrace();  
           }  
           conflation(fname);  
      }  
      private static void conflation(String fname)   
      {  
                BufferedReader buff;  
                try {  
                     buff = new BufferedReader(new FileReader(fname));  
                String line="", data="" ;  
                     line = buff.readLine();  
                while(line!=null)  
                {  
                     data+=line ;  
                     System.out.println(line);  
                     line=buff.readLine();  
                }  
                Pattern pattern= Pattern.compile("(ed,ing)|\\b(this |is |a |and |are |an |the)",Pattern.CASE_INSENSITIVE);  
                Matcher matcher = pattern.matcher(data);  
                String clean = matcher.replaceAll("");  
                StringTokenizer st = new StringTokenizer(clean);  
                String currenttoken = "" ;  
                ArrayList token = new ArrayList() ;  
                ArrayList count = new ArrayList() ;  
                while(st.hasMoreTokens())  
                {  
                     currenttoken = st.nextToken() ;  
                     int index = token.indexOf(currenttoken);  
                     if(index!=-1)  
                     {  
                          count.set(index,count.get(index+1 ));                    }  
                     else  
                     {  
                          token.add(currenttoken);  
                          count.add(1);  
                     }  
                }  
                System.out.println("OUTPUT IS:\nTOKENS\tNO OF OCCURENCES");  
                for(int i=0;i                     System.out.println(token.get(i)+"\t"+count.get(i));  
                }  
                } catch (IOException e) {  
                     // TODO Auto-generated catch block  
                     e.printStackTrace();  
                }  
      }  
 }