Write a Java code for the following requirement.

File encryption is the science of writing the contents of a file in a secret code.

The encryption program should work like a filter, reading the contents of one file, modifying the data into code, and then writing the code contents out to a second file. The second file will be a version of the first file, but written in a secret code.

Although there are complex encryption techniques, you should come up with a simple one of your own. For example, you could read the first file one character at a time and add 10 to the character code of each character before it is written to the second file.

import java. io. File;

import java. io. FileInputStream;

import java. io. FileNotFoundException;

import java. io. FileOutputStream;

import java. io. IOException;

import java. util. Scanner;

public class EncryptFileData

{

public static void main (String args[]) throws IOException, FileNotFoundException

{

String inputFileName="input. txt";

String outputFileName="EncryptedFile. txt";

String decryptFileName="DecryptedFile. txt";

byte codeValue;

Scanner sc=new Scanner (System. in);

//Accept code value from user

System. out. println ("Enter the value of code");

codeValue=sc. nextByte ();

//Encrypt the input file

encryptFileContent (inputFileName, codeValue, outputFileName);

//Decrypt the input file

decryptFileContent (outputFileName, codeValue, decryptFileName);

}

//function to encrypt the input file

private static void encryptFileContent (String inputFileName,

byte encodeValue, String outputFileName) throws IOException, FileNotFoundException{

File file = new File (inputFileName);

FileInputStream fin = new FileInputStream (file);

FileOutputStream fout = new FileOutputStream (outputFileName);

try{

while (fin. available () ! = 0) {

int inData = fin. read ();

//For every character in input add code value and

//write result to file "EncryptedFile. txt"

fout. write (inData+encodeValue);

}

}finally{

fin. close ();

fout. close ();

}

}

//function to decrypt the encrypted file

private static void decryptFileContent (String inputFileName,

byte encodeValue, String outputFileName) throws IOException, FileNotFoundException{

File file = new File (inputFileName);

FileInputStream fin = new FileInputStream (file);

FileOutputStream fout = new FileOutputStream (outputFileName);

try{

while (fin. available () ! = 0) {

int inData = fin. read ();

//For every character in encrypted file

//subtract the code value from each character and

//write it to file "DecryptedFile. txt"

fout. write (inData-encodeValue);

}

}finally{

fin. close ();

fout. close ();

}

}

}

Explanation:

Given the following conditions to follow in the question;

=> "The encryption program should work like a filter, reading the contents of one file, modifying the data into code, and then writing the code contents out to a second file. "

=> "The second file will be a version of the first file, but written in a secret code."

Thus, the Java code is given below (one can just copy and run it to give a sample output of: Enter the value of code 1 2.

The Java code is;

import java. io. File;

import java. io. FileInputStream;

import java. io. FileNotFoundException;

import java. io. FileOutputStream;

import java. io. IOException;

import java. util. Scanner;

public class EncryptFileData

{

public static void main (String args[]) throws IOException, FileNotFoundException

{

String inputFileName="input. txt";

String outputFileName="EncryptedFile. txt";

String decryptFileName="DecryptedFile. txt";

byte codeValue;

Scanner sc=new Scanner (System. in);

//Accept code value from user

System. out. println ("Enter the value of code");

codeValue=sc. nextByte ();

//Encrypt the input file

encryptFileContent (inputFileName, codeValue, outputFileName);

//Decrypt the input file

decryptFileContent (outputFileName, codeValue, decryptFileName);

}

//function to encrypt the input file

private static void encryptFileContent (String inputFileName,

byte encodeValue, String outputFileName) throws IOException, FileNotFoundException{

File file = new File (inputFileName);

FileInputStream fin = new FileInputStream (file);

FileOutputStream fout = new FileOutputStream (outputFileName);

try{

while (fin. available () ! = 0) {

int inData = fin. read ();

//For every character in input add code value and

//write result to file "EncryptedFile. txt"

fout. write (inData+encodeValue);

}

}finally{

fin. close ();

fout. close ();

}

}

//function to decrypt the encrypted file

private static void decryptFileContent (String inputFileName,

byte encodeValue, String outputFileName) throws IOException, FileNotFoundException{

File file = new File (inputFileName);

FileInputStream fin = new FileInputStream (file);

FileOutputStream fout = new FileOutputStream (outputFileName);

try{

while (fin. available () ! = 0) {

int inData = fin. read ();

//For every character in encrypted file

//subtract the code value from each character and

//write it to file "DecryptedFile. txt"

fout. write (inData-encodeValue);

}

}finally{

fin. close ();

fout. close ();

}

}

}