package examples;

import java.io.*;

import java.util.*;

public class JavaIOExamples {

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

String inputFile = "input.txt";

String encryptedFile = "encrypted.bin";

String decryptedFile = "decrypted.txt";

String mergedFile = "merged.bin";

String serializedFile = "data.bin";

String logFile = "log.txt";

// Call Encryption & Decryption

byte xorKey = 0x5A;

FileOperations.encryptDecryptFile(inputFile, encryptedFile, xorKey);

FileOperations.encryptDecryptFile(encryptedFile, decryptedFile, xorKey);

// Call Merge Files

FileOperations.mergeFiles(mergedFile, "file1.bin", "file2.bin");

// Call Serialization

FileOperations.serialize(serializedFile, "Anirudha Gaikwad", 30, 50000.50);

FileOperations.deserialize(serializedFile);

// Call Password Masking

FileOperations.readMaskedPassword();

// Call Chat Simulator

FileOperations.chatSimulator();

// Call Logging User Input

FileOperations.logUserInput(logFile);

}

}

class FileOperations {

/**

* 41) Encrypted File Transfer: Reads a binary file, encrypts its content using XOR cipher,

* and writes it to another file using FileInputStream and FileOutputStream. Implements decryption as well.

*/

public static void encryptDecryptFile(String inputFile, String outputFile, byte xorKey) throws IOException {

try (FileInputStream fis = new FileInputStream(inputFile);

FileOutputStream fos = new FileOutputStream(outputFile)) {

int data;

while ((data = fis.read()) != -1) {

fos.write(data ^ xorKey);

}

}

}

/**

* 42) Merging Large Binary Files: Merges multiple large binary files into a single file using

* BufferedInputStream and BufferedOutputStream.

*/

public static void mergeFiles(String outputFile, String... inputFiles) throws IOException {

try (BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(outputFile))) {

for (String inputFile : inputFiles) {

try (BufferedInputStream bis = new BufferedInputStream(new FileInputStream(inputFile))) {

byte[] buffer = new byte[8192];

int bytesRead;

while ((bytesRead = bis.read(buffer)) != -1) {

bos.write(buffer, 0, bytesRead);

}

}

}

}

}

/**

* 43) Custom Serialization: Serializes and deserializes an object using DataOutputStream and DataInputStream.

*/

public static void serialize(String outputFile, String name, int age, double salary) throws IOException {

try (DataOutputStream dos = new DataOutputStream(new FileOutputStream(outputFile))) {

dos.writeUTF(name);

dos.writeInt(age);

dos.writeDouble(salary);

}

}

public static void deserialize(String inputFile) throws IOException {

try (DataInputStream dis = new DataInputStream(new FileInputStream(inputFile))) {

System.out.println("Name: " + dis.readUTF() + ", Age: " + dis.readInt() + ", Salary: " + dis.readDouble());

}

}

/**

* 51) Password Masking on Console: Reads password securely.

*/

public static void readMaskedPassword() {

Console console = System.console();

if (console == null) {

System.out.println("No console available.");

return;

}

char[] password = console.readPassword("Enter password: ");

System.out.println("Password entered: " + "*".repeat(password.length));

}

/**

* 52) Interactive Command-line Chat: Simulated chat responses.

*/

public static void chatSimulator() throws IOException {

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

System.out.println("Type 'exit' to quit.");

String input;

while (!(input = br.readLine()).equalsIgnoreCase("exit")) {

System.out.println("Chatbot: " + input.toUpperCase());

}

}

/**

* 53) Logging User Input to a File: Logs user input with timestamps.

*/

public static void logUserInput(String logFile) throws IOException {

try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

PrintWriter pw = new PrintWriter(new FileWriter(logFile, true))) {

String input;

while (!(input = br.readLine()).equalsIgnoreCase("exit")) {

pw.println(new Date() + " - " + input);

}

}

}

}