Reading individual fields in an FTP input Stream

Hi I have a java method which uses a streaming FTP connection to a remote file. My problem is that I do not know
how  split the buffer read in into individual fileds  so I can manipulate them.  The code is as follows:

NB I have entered another related question to this problem recently, but that  requires more comprehensive design details and this one is specific to geting the data from the input stream.


public static boolean getDataFiles( String _host,String _user,String _password,String destinationFolder,String strDate)  {
       try
       {      
                      
             String host= _host;  String user= _user;  String password= _password;
             URLConnection  urlc = null;
            
             String targetfile= ""Data" + strDate + "_v4.dat";
          
             URL url = new  URL("ftp://"+ user+ ":"+ password+ "@"+ host+ "/"+ targetfile+ ";type=i");    
             urlc = url.openConnection();
             urlc.setDoInput(true);
             InputStream is = urlc.getInputStream();

             byte[] buf= new byte[16384];
             for(int br = is.read(buf); br > -1; br = is.read(buf))
             {
                                                  //**** get individual fields from buffer delimited by comma***
                   //System.out.write(buf, 0 , br);
                  
             }
             is.close();
                   
       }
       
       catch (Exception E)
       {
             System.err.println(E.getMessage());
             E.printStackTrace();
       }      

       return true;  
      
 }

Thanks

azsat