Java 我应该使用什么来比较密码应用程序上的前两个输入字符串 我想在一开始就补充一点，如果密码不匹配，重新开始…但每次我尝试这样做，我就会把整个事情搞砸 密码长度必须为8个字符，一个大写字母和一个数字

我遇到的一些问题是，如果第一个密码无效，它仍然会要求第二个确认密码，为什么在第一个密码无效时继续4.我想可能是compareTo（）方法或compareChar，因为它可以是数字，.equals？我愿意接受任何其他优化性能的建议和技巧，因为我知道我的代码是草率的

公共静态void main（字符串[]args）{ 扫描仪输入=新扫描仪（系统输入）； 系统输出打印（“请输入密码：”）； 字符串password=in.nextLine（）

}

公共静态布尔值isValid（字符串密码）{ 布尔值atleastOneUpper=false； 布尔值atleastOneLower=false； 布尔值至少一位数=false； 如果（password.length（）<8）{//如果少于8个字符，则其自动无效 返回false； }

for（inti=0；i

}

公共静态字符串密码检查（字符串密码）{

String result=“Valid Password”//设置有效密码
int length=0；//存储#
int numCount=0；//在密码中存储数字
int capCount=0；//用于在密码中存储大写字母的变量
对于（int x=0；x=47&&Password.charAt（x）=64&&Password.charAt（x）=97&&Password.charAt（x）47&&Password.charAt（x）<58））{//
numCount++；
}
if（（Password.charAt（x）>64&&Password.charAt（x）<91））{//计算大写字母数
capCount++；
}
长度=（x+1）；//检查密码长度
}//结束for循环
如果（numCount<1）{//检查数字
结果=“密码中的数字不够！”；
}
如果（capCount<1）{//检查大写字母
结果=“您至少需要大写字母！”；
}
如果（长度<7）{//检查长度
result=“密码长度必须为7个字符”；
}
返回（结果）；}

---

通过稍微修改已有的逻辑，基本上可以实现您想要的。无需对代码进行任何重大重构，您可以执行以下操作：

String password = "";    
System.out.print("Please enter password : ");
while(!isValid(password)) {                     
    password = in.nextLine();
    if(!isValid(password)) {
        System.out.println(PassCheck(password));
        System.out.print("Password is not valid, try again : ");
    }
}

具有所需结果的样本输出：

Please enter password : test
Password is not valid, try again : test2
Password is not valid, try again : Test1test
Please re-enter the password to confirm : Test1test
The password is valid

完整代码：

public class Password {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);

        String password = "";    
        System.out.print("Please enter password : ");
        while(!isValid(password)) {                     
            password = in.nextLine();
            if(!isValid(password)) {
                System.out.println(PassCheck(password));
                System.out.print("Password is not valid, try again : ");
            }
        }

        System.out.print("Please re-enter the password to confirm : ");
        String confirm = in.nextLine();

        boolean condition;
        condition = isValid(password);
        while (!password.equals(confirm) || (!condition)) {
            System.out.println("The password is invalid");

            System.out.print("Please enter the password again : ");
            password = in.nextLine();
            System.out.println(PassCheck(password));
            System.out.print("Please re-enter the password to confirm : ");
            confirm = in.nextLine();
            System.out.println(PassCheck(password));
            condition = isValid(password);

        }
        if (isValid(password)) {
            System.out.println("The password is valid");

        }
    }

    public static boolean isValid(String password) {
        Boolean atleastOneUpper = false;
        Boolean atleastOneLower = false;
        Boolean atleastOneDigit = false;
        if (password.length() < 8) { // If its less then 8 characters, its automatically not valid
            return false;
        }

        for (int i = 0; i < password.length(); i++) { // Lets iterate over only once. Saving time
            if (Character.isUpperCase(password.charAt(i))) {
                atleastOneUpper = true;
            } else if (Character.isLowerCase(password.charAt(i))) {
                atleastOneLower = true;
            } else if (Character.isDigit(password.charAt(i))) {
                atleastOneDigit = true;
            }
        }

        return (atleastOneUpper && atleastOneLower && atleastOneDigit); // Return true IFF the password is atleast eight characters long, has atleast one upper, lower and digit
    }

    public static String PassCheck(String Password) {

        String result = "Valid Password";           // Sets  valid
        int length = 0;                     // Stores the #
        int numCount = 0;                   // store numbers in the password
        int capCount = 0;                                       // Variable used to store capital letters in the password


        for (int x = 0; x < Password.length(); x++) {
            if ((Password.charAt(x) >= 47 && Password.charAt(x) <= 58) || (Password.charAt(x) >= 64 && Password.charAt(x) <= 91)
                    || (Password.charAt(x) >= 97 && Password.charAt(x) <= 122)) {

            } else {
                result = "Password Contains Invalid Character!";//Checks that password contains only letters and numbers
            }

            if ((Password.charAt(x) > 47 && Password.charAt(x) < 58)) { // Counts the number of numbers
                numCount++;
            }

            if ((Password.charAt(x) > 64 && Password.charAt(x) < 91)) { // Counts the number of capital letters
                capCount++;
            }

            length = (x + 1);                   // check passwords length

        } // Ends the for loop

        if (numCount < 1) {                     // Checks numbers
            result = "Not Enough Numbers in Password!";
        }

        if (capCount < 1) {             // Checks that Capital letters
            result = "You need atleast least Capital letter!";
        }

        if (length < 7) {               // Checks length
            result = "Password needs to be 7 characters long";
        }

        return (result);
    }
}

公共类密码{
公共静态void main（字符串[]args）{
扫描仪输入=新扫描仪（系统输入）；
字符串密码=”；
系统输出打印（“请输入密码：”）；
而（！isValid（password））{
password=in.nextLine（）；
如果（！isValid（密码））{
System.out.println（PassCheck（password））；
System.out.print（“密码无效，请重试：”）；
}
}
System.out.print（“请重新输入密码以确认：”）；
字符串confirm=in.nextLine（）；
布尔条件；
条件=有效（密码）；
而（！password.equals（confirm）| |（！condition））{
System.out.println（“密码无效”）；
System.out.print（“请再次输入密码：”）；
password=in.nextLine（）；
System.out.println（PassCheck（password））；
System.out.print（“请重新输入密码以确认：”）；
confirm=in.nextLine（）；
System.out.println（PassCheck（password））；
条件=有效（密码）；
}
如果（有效（密码））{
System.out.println（“密码有效”）；
}
}
公共静态布尔值isValid（字符串密码）{
布尔值atleastOneUpper=false；
布尔值atleastOneLower=false；
布尔值至少一位数=false；
如果（password.length（）<8）{//如果少于8个字符，则其自动无效
返回false；
}
对于（inti=0；i=47&&Password.charAt（x）=64&&Password.charAt（x）=97&&Password.charAt（x）47&&Password.charAt（x）<58））{//
numCount++；
}
String password = "";    
System.out.print("Please enter password : ");
while(!isValid(password)) {                     
    password = in.nextLine();
    if(!isValid(password)) {
        System.out.println(PassCheck(password));
        System.out.print("Password is not valid, try again : ");
    }
}

Please enter password : test
Password is not valid, try again : test2
Password is not valid, try again : Test1test
Please re-enter the password to confirm : Test1test
The password is valid

public class Password {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);

        String password = "";    
        System.out.print("Please enter password : ");
        while(!isValid(password)) {                     
            password = in.nextLine();
            if(!isValid(password)) {
                System.out.println(PassCheck(password));
                System.out.print("Password is not valid, try again : ");
            }
        }

        System.out.print("Please re-enter the password to confirm : ");
        String confirm = in.nextLine();

        boolean condition;
        condition = isValid(password);
        while (!password.equals(confirm) || (!condition)) {
            System.out.println("The password is invalid");

            System.out.print("Please enter the password again : ");
            password = in.nextLine();
            System.out.println(PassCheck(password));
            System.out.print("Please re-enter the password to confirm : ");
            confirm = in.nextLine();
            System.out.println(PassCheck(password));
            condition = isValid(password);

        }
        if (isValid(password)) {
            System.out.println("The password is valid");

        }
    }

    public static boolean isValid(String password) {
        Boolean atleastOneUpper = false;
        Boolean atleastOneLower = false;
        Boolean atleastOneDigit = false;
        if (password.length() < 8) { // If its less then 8 characters, its automatically not valid
            return false;
        }

        for (int i = 0; i < password.length(); i++) { // Lets iterate over only once. Saving time
            if (Character.isUpperCase(password.charAt(i))) {
                atleastOneUpper = true;
            } else if (Character.isLowerCase(password.charAt(i))) {
                atleastOneLower = true;
            } else if (Character.isDigit(password.charAt(i))) {
                atleastOneDigit = true;
            }
        }

        return (atleastOneUpper && atleastOneLower && atleastOneDigit); // Return true IFF the password is atleast eight characters long, has atleast one upper, lower and digit
    }

    public static String PassCheck(String Password) {

        String result = "Valid Password";           // Sets  valid
        int length = 0;                     // Stores the #
        int numCount = 0;                   // store numbers in the password
        int capCount = 0;                                       // Variable used to store capital letters in the password


        for (int x = 0; x < Password.length(); x++) {
            if ((Password.charAt(x) >= 47 && Password.charAt(x) <= 58) || (Password.charAt(x) >= 64 && Password.charAt(x) <= 91)
                    || (Password.charAt(x) >= 97 && Password.charAt(x) <= 122)) {

            } else {
                result = "Password Contains Invalid Character!";//Checks that password contains only letters and numbers
            }

            if ((Password.charAt(x) > 47 && Password.charAt(x) < 58)) { // Counts the number of numbers
                numCount++;
            }

            if ((Password.charAt(x) > 64 && Password.charAt(x) < 91)) { // Counts the number of capital letters
                capCount++;
            }

            length = (x + 1);                   // check passwords length

        } // Ends the for loop

        if (numCount < 1) {                     // Checks numbers
            result = "Not Enough Numbers in Password!";
        }

        if (capCount < 1) {             // Checks that Capital letters
            result = "You need atleast least Capital letter!";
        }

        if (length < 7) {               // Checks length
            result = "Password needs to be 7 characters long";
        }

        return (result);
    }
}