/** 
 * This program is an example from the book "Internet 
 * programming with Java" by Svetlin Nakov. It is freeware. 
 * For more information: http://www.nakov.com/books/inetjava/ 
 */ 
import java.io.*; 
import java.lang.*; 
 
public class TextFileLineNumberInserter { 
    public static void main(String[] args) throws IOException { 
        FileReader inFile = new FileReader("input.txt"); 
        BufferedReader in = new BufferedReader(inFile); 
 
        FileWriter outFile = new FileWriter("output.txt"); 
        PrintWriter out = new PrintWriter(outFile); 
 
        int lineNumberCounter = 0; 
        String line; 
        while ( (line=in.readLine()) != null ) { 
            lineNumberCounter++; 
            out.println(lineNumberCounter + " " + line); 
        } 
 
        in.close(); 
        out.close(); 
    } 
}