如何使密码的输入字段变成星号？

Question

当用户输入密码时，我正在尝试使输入字段变为 *****。 但是在这里我遇到了 2 个错误，如下所示。 我该如何解决这个问题。 有人可以帮助修改此代码，使其正常工作。 谢谢你。

//package com.company;

import java.util.Scanner;
import java.io.Console;
public class Main {
    static void myPassword(){
        String Username = "wisdom";
        String Password = "123";
        boolean granted = false;

        for(int i = 0; i < 3; i++) {
            Scanner input1 = new Scanner(System.in);
            Console console = System.console();
            char[] password = console.readPassword("Enter password");  
            Arrays.fill(password, '*');
            String username = input1.next();

            Scanner input2 = new Scanner(System.in);
            System.out.println("Enter Password : ");
            String password = input2.next();

            if (username.equals(Username) && password.equals(Password)) {
                granted = true;
                break;
            }
            else if (username.equals(Username)) {
                System.out.println("Invalid Password!");
            } else if (password.equals(Password)) {
                System.out.println("Invalid Username!");
            } else {
                System.out.println("Invalid Username & Password!");
            }
        }

        if(granted)
            System.out.println("Access Granted! Welcome!");
        else
            System.out.println("Access Denied! You have reached the maximum number of attempts");
            System.exit(0);
    }

    public static void main(String[] args) {
        myPassword();

    }
}

Answer 1

第一个错误：需要先导入Arrays才能使用：

import java.util.Arrays;

第二个错误：您已经在这里初始化了password变量：

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

选择另一个变量名来代替：

String password = input2.next();

Answer 2

我认为这里的错误是不言自明的。

对于第一个错误： Arrays.fill(password, '*'); ，缺少以下导入语句。

import java.util.Arrays;

对于第二个错误： String password = input2.next(); , 变量密码已经定义在char[] password = console.readPassword("Enter password"); . 只需在此处使用不同的变量名称。

Answer 3

也许您可以通过答案来理解为什么会出现错误。 因此我建议了我的源代码

import java.util.Scanner;
import java.io.Console;

public class Main {
    static void myPassword(){
        String username = "wisdom";
        String password = "123";
        boolean granted = false;

        Console console = System.console();
        Scanner scanner = new Scanner(System.in);
    
        for(int i = 0; i < 3; i++) {
            System.out.println("Enter username : ");
            // i suggested variable should distinguished by name
            String inputUsername = scanner.next();
        
            char[] passwordChar = console.readPassword("Enter password");  
        
            // this need import java.util.Arrays;
            // and if use this element of passwordChar[] changed *
            //Arrays.fill(passwordChar, '*');
        
            String inputPassword = new String(passwordChar);

           if (username.equals(inputUsername) && password.equals(inputPassword)) {
                granted = true;
                break;
            }
        
            else if (username.equals(inputUsername)) {
                System.out.println("Invalid Password!");
            } else if (password.equals(inputPassword)) {
                System.out.println("Invalid Username!");
            } else {
                System.out.println("Invalid Username & Password!");
            }
        }
        //If you don't need to use scanner
        //You had better close scanner
        scanner.close();
    
        if(granted)
            System.out.println("Access Granted! Welcome!");
        else
            System.out.println("Access Denied! You have reached the maximum number of attempts");
            System.exit(0);
    }

    public static void main(String[] args) {
        myPassword();

    }
}