Question

Please do in java as simply as possible with code available for copy and comments

Write a program that reads a file (provided as attachment to this assignment) and writes the file to a different file with line numbers inserted at the beginning of each line. Throw an exception if the file does not exist. An error message should result.

For example if file input is: This is a test File output should be

1. This is a test

I cant seem to attach the file, because it is a .txt but it reads:

This file contains
lines of text to
determine if you can
properly read and
write from a file.

let me know if you have any questions!

Answer 1

SOURCE CODE IN JAVA:

import java.util.Scanner;

import java.io.FileWriter;

import java.io.File;

class Main

{

public static void main(String[] args)

{

//storing names of input and output files

final String txtIn="test.txt", txtOut="test_numbered.txt";

try

{

//opening file for input

Scanner in=new Scanner(new File(txtIn));

//opening file for output

FileWriter out=new FileWriter(new File(txtOut));

int lineNum=1; //to store current line number

while(in.hasNextLine()) //while input file has next line to read

{

String line=in.nextLine(); //reading line

out.write(lineNum+". "+line+"\n"); //writing line with line number

lineNum+=1; //updating line number

}

//closing input and output files

in.close();

out.close();

}

catch(Exception e) //catching exceptions

{

System.out.println(e); //error message

}

}

}

INPUT FILE:

OUTPUT FILE: