密码生成器(如何在此程序中添加构造函数)

Question

这是我从头开始制作的密码生成器，但我想添加一个构造函数，以便我可以将其用于调用目的，还需要创建另一个类来调用它。如果可能的话，我想在此程序上获得一些帮助。因此，我的程序基本上解释了生成随机数符号，大小情况和小写字母。我第一次创建密码生成器代码时的工作不佳，因为它给了我所有大写，有时甚至没有其他变量的符号然后，我制作了此代码，我告诉程序，如果此变量不存在，则在显示这些变量之前将无法创建其他变量。

  import java.util.Scanner;
         class Passwd {
             public Passwd()
             {
                 System.out.println("Hello");
             }

            public static void main(String[] args) {
                 new Passwd();
                 Scanner in;`enter code here`
                in = new Scanner(System.in);
                int choice = 0;
                while (choice != 5) {
                    System.out.println("                Password Generation Menu                ");
                    System.out.println("********************************************************");
                    System.out.println("*  [1] Lowercase Letters                               *");
                    System.out.println("*  [2] Lowercase & Uppercase Letters                   *");
                    System.out.println("*  [3] Lowercase, Uppercase, and Numbers               *");
                    System.out.println("*  [4] Lowercase, Uppercase, Numbers, and Symbols  *");
                    System.out.println("*  [5] Quit                                            *");
                    System.out.println("********************************************************");
                    System.out.println("Enter Selection (1-5): ");
                    choice = in.nextInt();
                    if (choice < 1 || choice > 5)
                        System.out.println("Incorrect option....  ");
                    else if (choice > 0 && choice < 5) {
                        System.out.println("Password Length (1-14): ");
                        int passwordLength = in.nextInt();
                        char[] password = new char[passwordLength];
                        int randNum = 0;
                        if (choice == 1) {
                            for (int i = 0; i < passwordLength; i++) {
                                randNum = ((int) (Math.random() * 26 + 97));
                                while (randNum < 97 || randNum > 122) {
                                    randNum = ((int) (Math.random() * 26 + 97));
                                }
                                password[i] = (char) randNum;
                            }
                        }
                        if (choice == 2) {
                            randNum = ((int) (Math.random() * 26 + 97));
                            while (randNum < 97 || randNum > 122) {
                                randNum = ((int) (Math.random() * 26 + 97));
                            }
                            password[0] = (char) randNum;
                            randNum = ((int) (Math.random() * 26 + 65));
                            while (randNum < 65 || randNum > 90) {
                                randNum = ((int) (Math.random() * 26 + 65));
                            }
                            password[1] = (char) randNum;
                            for (int i = 2; i < passwordLength; i++) {
                                randNum = ((int) (Math.random() * 122 - 65 + 1)) + 65;
                                while ((randNum < 65 || randNum > 90) && (randNum < 97 || randNum > 122)) {
                                    randNum = ((int) (Math.random() * 122 - 65 + 1)) + 65;
                                }
                                password[i] = (char) randNum;
                            }
                        }
                        if (choice == 3) {
                            randNum = ((int) (Math.random() * 26 + 97));
                            while (randNum < 97 || randNum > 122) {
                                randNum = ((int) (Math.random() * 26 + 97));
                            }
                            password[0] = (char) randNum;
                            randNum = ((int) (Math.random() * 26 + 65));
                            while (randNum < 65 || randNum > 90) {
                                randNum = ((int) (Math.random() * 26 + 65));
                            }
                            password[1] = (char) randNum;
                            randNum = ((int) (Math.random() * 26 + 48));
                            while (randNum < 48 || randNum > 57) {
                                randNum = ((int) (Math.random() * 26 + 48));
                            }
                            password[2] = (char) randNum;
                            for (int i = 3; i < passwordLength; i++) {
                                randNum = ((int) (Math.random() * 122 - 48 + 1)) + 48;
                                while ((randNum < 65 || randNum > 90) && (randNum < 97 || randNum > 122) && (randNum < 48 || randNum > 57)) {
                                    randNum = ((int) (Math.random() * 122 - 48 + 1)) + 48;
                                }
                                password[i] = (char) randNum;
                            }
                        }
                        if (choice == 4) {
                            randNum = ((int) (Math.random() * 26 + 97));
                            while (randNum < 97 || randNum > 122) {
                                randNum = ((int) (Math.random() * 26 + 97));
                            }
                            password[0] = (char) randNum;
                            randNum = ((int) (Math.random() * 26 + 65));
                            while (randNum < 65 || randNum > 90) {
                                randNum = ((int) (Math.random() * 26 + 65));
                            }
                            password[1] = (char) randNum;
                            randNum = ((int) (Math.random() * 10 + 48));
                            while (randNum < 48 || randNum > 57) {
                                randNum = ((int) (Math.random() * 10 + 48));
                            }
                            password[2] = (char) randNum;
                            randNum = ((int) (Math.random() * 7 + 33));
                            while (randNum < 33 || randNum > 39) {
                                randNum = ((int) (Math.random() * 7 + 33));
                            }
                            password[3] = (char) randNum;
                            for (int i = 4; i < passwordLength; i++) {
                                randNum = ((int) (Math.random() * 122 - 33 + 1)) + 33;
                                while ((randNum < 65 || randNum > 90) && (randNum < 97 || randNum > 122) && (randNum < 48 || randNum > 57) && (randNum < 33 || randNum > 39)) {
                                    randNum = ((int) (Math.random() * 122 - 33 + 1)) + 33;
                                }
                                password[i] = (char) randNum;
                            }
                        }

                        for (int j = 0; j < passwordLength; j++)
                            System.out.print(password[j]);
                        System.out.println("n");
                    }
                }
                System.out.println("Thank You for using World's Best Password generator n");
            }
        }

Answer 1

您可以做的是应用OO原理，并创建一个负责生成密码的类，例如PasswordGenerator。看起来像：

public class PasswordGenerator {
  public String generatePassword(int passwordType) {
    // All your password generation logic
  }
}

因此您可以在另一堂课中使用它。

public class PasswordThing {
  public void doSomethingWithPassword() {
    PasswordGenerator passwordGenerator = new PasswordGenerator();
    String password = password.generatePassword(1);
    // ...
  }
  // or
  public static void main(String[] args) {
      // Get user choice from command line as you did in your sample
    PasswordGenerator passwordGenerator = new PasswordGenerator();
    String password = passwordGenerator.generatePassword(userChoice);
    // ...
  }
}