Question

I need help with a java program

Write a program Enigma that takes a single String as a command line argument. Enigma should read the file specified by the String argument, add 5 to each byte, and leave the altered data values in a file whose name is the command line argument. Note that this "updating in place" is the most difficult part of this lab: java Enigma sophie.dat should read file sophie.dat, and upon completion, leave the modified data in file sophie.dat.

Answer 1

import java.io.*;

public class Enigma {

public static void main(String args[]) throws Exception

{ String modified_data="";

//read filename through command line

String Filename=args[0];

//openfile through filereader

FileReader fread=new FileReader(Filename);

//read the file by bytes and add 5

int a;

while((a=fread.read())!=-1)   

{//System.out.print((char)a+" "+(char)(a+5)+"\n");

a+=5;

modified_data+=((char)a);

}

//close file

fread.close();

  

  

// attach a file to FileWriter

FileWriter fw=new FileWriter(Filename);

// read character wise from string and write

// into FileWriter

for (int i = 0; i < modified_data.length(); i++)

fw.write(modified_data.charAt(i));

//close the file

fw.close();

  

System.out.println("Encryption completed.(note spaces,newlines are also encrypted)");

}

  

}

//before encryption

//after encryption