import java.io.BufferedReader;
import java.io.FileReader;
import java.io.BufferedReader;
import java.io.FileWriter;
import java.io.PrintWriter;
import java.io.IOException;
import java.io.FileNotFoundException;

/*
  Author:  James Tam
  Version: 2015

  Learning objective: 
  * file input via FileReader and BufferedReader.
  * file output via FileWriter and PrintWriter.
*/

public class DriverFileExample 
{
    public static void main (String [] args) 
    {
        BufferedReader br;
        FileReader fr;
        FileWriter fw;
        PrintWriter pw;
        String s = "";
        String wholeString = "";
        int i = 1;
        try 
        {
            fr = new FileReader("data.txt");
            br = new BufferedReader(fr);
            // Read text from file and append onto the end the line count
            // and a newline.
            while (s != null) 
            {
                s = br.readLine();
                if (s != null) 
                {
                    System.out.println(s);
                    wholeString = wholeString + i + " " + s + "\n";
                }
                i = i + 1;
            }   
            br.close();
        }
        catch (FileNotFoundException e) 
        {
            System.out.println("data.txt not in current folder"); 
            e.printStackTrace();
        }
        catch (IOException e) 
        {
            e.printStackTrace();
        }

        // Write the appended text from above to file (includes line
        // numbering and extra newlines).
        try 
        {
            fw = new FileWriter("data_appended.txt");
            pw = new PrintWriter(fw);
            pw.write(wholeString);
            fw.close();
        }
        catch (IOException e) 
        {
            e.printStackTrace();
        }
    }
}