Registration

[Naman-2003]

package Learn_and_Build;

//BufferedReader is a class that allows efficient reading of text from a character-input stream.
import java.io.BufferedReader;
// BufferedReader is a class that allows efficient reading of text from a character-output stream..
import java.io.BufferedWriter;
// FileReader is a class that reads character files.
import java.io.FileReader;
//FileWriter is a class that writes character files.
import java.io.FileWriter;
// IOException is a class that is used to handle errors
import java.io.IOException;
//Scanner is a class that is used to read input from the console or other input sources.
import java.util.Scanner;

public class RegistrationAndLogin {

public static void main(String[] args) {

    Scanner scanner = new Scanner(System.in);
    int choice;

    do {
        System.out.println("Welcome to the program!");
        System.out.println("1. Register");
        System.out.println("2. Login");
        System.out.println("3. Exit");
        System.out.print("Enter your choice: ");
        choice = scanner.nextInt();
        scanner.nextLine(); // consume the newline character

        switch (choice) {
            case 1:
                registerUser(scanner);
                break;
            case 2:
                loginUser(scanner);
                break;
            case 3:
                System.out.println("Exiting program...");
                break;
            default:
                System.out.println("Invalid choice. Try again.");
                break;
        }
    } while (choice != 3);

    scanner.close();
}

private static void registerUser(Scanner scanner) {
    System.out.println("Enter your name:");
    String name = scanner.nextLine();
    System.out.println("Enter your email address:");
    String email = scanner.nextLine();
    System.out.println("Enter your password:");
    String password = scanner.nextLine();

    //The write() method of the BufferedWriter object is called to write the user's information to the file(txt).

    try (BufferedWriter writer = new BufferedWriter(new FileWriter("users.txt", true))) {
        writer.write(name + "," + email + "," + password + "\n");
        System.out.println("Registration successful!");
    } catch (IOException e) {
        System.out.println("Error writing to file: " + e.getMessage());
    }
}

private static void loginUser(Scanner scanner) {
    System.out.println("Enter your email address:");
    String email = scanner.nextLine();
    System.out.println("Enter your password:");
    String password = scanner.nextLine();

    try (BufferedReader reader = new BufferedReader(new FileReader("users.txt"))) {
        String line;
        boolean found = false;
        while ((line = reader.readLine()) != null) {
            String[] parts = line.split(",");
            if (parts.length == 3 && parts[1].equals(email) && parts[2].equals(password)) {
                found = true;
                break;
            }
        }
        if (found) {
            System.out.println("Login successful!");
        } else {
            System.out.println("Invalid email or password. Try again.");
        }
    } catch (IOException e) {
        System.out.println("Error reading from file: " + e.getMessage());
    }
}

}