Question

我最近在java中制作了一个密码锁定的东西来测试我学习哈希映射的技巧。这是我的代码：

package com.Zach.Password;

import java.util.HashMap;
import java.util.Random;
import java.util.Scanner;

public class Password 
{
public static void main(String[] args)
{
    @SuppressWarnings("resource")
    Scanner in = new Scanner(System.in);
    Random r = new Random();
    HashMap<String, String> names = new HashMap<String, String>();
    HashMap<String, Integer> passwords = new HashMap<String, Integer>();
    HashMap<String, Integer> randNums = new HashMap<String, Integer>();

    while(true)
    {
        System.out.println("Please enter your name!!");
        String name = in.nextLine();
        if(names.containsKey(name))
        {
            int tries = 2;
            while(tries != 0)
            {
                if(tries != 0)
                {
                    System.out.println("What is your password?");
                    int normPassword = in.nextInt();

                    if(normPassword == passwords.get(name))
                    {
                        System.out.println("Welcome, " + name);
                        System.out.println("This is your random number:\n");
                        break;
                    }
                    else
                        System.out.println("INCORRECT");
                }
                else if(tries == 0)
                {
                    System.out.println("This account is locked! Unlock it by entering your random number!!");
                    int lockedRand = in.nextInt();
                    if(lockedRand == randNums.get(name))
                    {
                        System.out.println("Welcome, " + name);
                        System.out.println("This is your random number:\n");
                        break;
                    }
                    else
                        System.out.println("INCORRECT");
                }
            }
        }
        else
        {
            int randNum = 1 + r.nextInt(99);
            randNums.put(name, randNum);
            names.put(name, name);
            System.out.println("Enter a password!!");
            int password = in.nextInt();
            passwords.put(name, password);
            System.out.println("Welcome, " + name);
            System.out.println("This is your random number:\n" + randNum);
        }
    }
}

}

我不确定问题是什么，但每当你输入一个名字时，如果名字包含密钥，它会转到else语句...我不会停止程序并重新运行...它只是不会失败那里。

Answer 1

您必须使用in.nextLine()替换in.next();来扫描名称。在提交用户输入之前，in.next();会阻止您的应用程序。 in.nextLine()为您提供当前行的其余部分并更改位置。因此，如果用户没有给出输入，它只返回空字符串。

Hashmaps密码锁java

1 个答案: