Random_password_Generator.java

import java.security.SecureRandom;
import java.util.Scanner;

public class Random_password_Generator {
    private static final String LOWERCASE = "abcdefghijklmnopqrstuvwxyz";
    private static final String UPPERCASE = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    private static final String NUMBERS = "0123456789";
    private static final String SPECIAL_CHARACTERS = "!@#$%^&*()-_+=<>?/";

    public static String generatePassword(int length, boolean useLower, boolean useUpper, boolean useNumbers, boolean useSpecial) {
        String characterPool = "";
        if (useLower) characterPool += LOWERCASE;
        if (useUpper) characterPool += UPPERCASE;
        if (useNumbers) characterPool += NUMBERS;
        if (useSpecial) characterPool += SPECIAL_CHARACTERS;
        
        if (characterPool.isEmpty()) {
            throw new IllegalArgumentException("At least one character type must be selected.");
        }
        
        SecureRandom random = new SecureRandom();
        StringBuilder password = new StringBuilder();
        
        for (int i = 0; i < length; i++) {
            int index = random.nextInt(characterPool.length());
            password.append(characterPool.charAt(index));
        }
        
        return password.toString();
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        
        System.out.print("Enter desired password length: ");
        int length = scanner.nextInt();
        
        System.out.print("Include lowercase letters? (true/false): ");
        boolean useLower = scanner.nextBoolean();
        
        System.out.print("Include uppercase letters? (true/false): ");
        boolean useUpper = scanner.nextBoolean();
        
        System.out.print("Include numbers? (true/false): ");
        boolean useNumbers = scanner.nextBoolean();
        
        System.out.print("Include special characters? (true/false): ");
        boolean useSpecial = scanner.nextBoolean();
        
        try {
            String password = generatePassword(length, useLower, useUpper, useNumbers, useSpecial);
            System.out.println("Generated Password: " + password);
        } catch (IllegalArgumentException e) {
            System.out.println(e.getMessage());
        }
        
        scanner.close();
    }
}