Question

所以我写了一个让用户输入密码的方法，这个密码必须通过以下规范：

1。长度至少为8位

2. 大写

3. 小写

4. 有特殊数字

我不确定为什么当我输入它时，输出不考虑特殊字符并抛出错误。

到目前为止，这是我的代码：

public static void main(String[] args) {

    Scanner in = new Scanner(System.in);
    System.out.print("Please enter a given  password : ");
    String passwordhere = in.nextLine();
    System.out.print("Please re-enter the password to confirm : ");
    String confirmhere = in.nextLine();
    System.out.println("your password is: " + passwordhere);

    while (!passwordhere.equals(confirmhere) || !isValid(passwordhere)) {
        System.out.println("The password entered here  is invalid");
        System.out.print("Please enter the password again.it must be valid : ");
        String Passwordhere = in.nextLine();
        System.out.print("Please re-enter the password to confirm : ");

    }
}

public static boolean isValid(String passwordhere) {

    if (passwordhere.length() < 8) {
        return false;
    } else {

        for (int p = 0; p < passwordhere.length(); p++) {
            if (Character.isUpperCase(passwordhere.charAt(p))) {
            }
        }
        for (int q = 0; q < passwordhere.length(); q++) {
            if (Character.isLowerCase(passwordhere.charAt(q))) {
            }
        }
        for (int r = 0; r < passwordhere.length(); r++) {
            if (Character.isDigit(passwordhere.charAt(r))) {
            }
        }
        for (int s = 0; s < passwordhere.length(); s++) {
            if (Character.isSpecialCharacter(passwordhere.charAt(s))) {
            } 
            }
            return true;
        }
}

另外，另一个问题是，例如，假设用户输入bob123作为他们的密码。

如何让循环告诉用户需要什么才能成为正确的密码？

在上面的示例中，它缺少大写字母和符号（*＆amp; ^ ..等）。

如何在每次用户输入密码时将其添加到打印输出中，直到他们获得正确的密码来传递代码的所有规格？

Answer 1

你应该清楚地提到你的要求我不知道你的要求。请找到我的下面的解决方案`

public static void main(String[] args) {

    Scanner in = new Scanner(System.in);
    System.out.print("Please enter a given  password : ");
    String passwordhere = in.nextLine();
    System.out.print("Please re-enter the password to confirm : ");
    String confirmhere = in.nextLine();

    List<String> errorList = new ArrayList<String>();

    while (!isValid(passwordhere, confirmhere, errorList)) {
        System.out.println("The password entered here  is invalid");
        for (String error : errorList) {
            System.out.println(error);
        }

        System.out.print("Please enter a given  password : ");
        passwordhere = in.nextLine();
        System.out.print("Please re-enter the password to confirm : ");
        confirmhere = in.nextLine();
    }
    System.out.println("your password is: " + passwordhere);

}

public static boolean isValid(String passwordhere, String confirmhere, List<String> errorList) {

    Pattern specailCharPatten = Pattern.compile("[^a-z0-9 ]", Pattern.CASE_INSENSITIVE);
    Pattern UpperCasePatten = Pattern.compile("[A-Z ]");
    Pattern lowerCasePatten = Pattern.compile("[a-z ]");
    Pattern digitCasePatten = Pattern.compile("[0-9 ]");
    errorList.clear();

    boolean flag=true;

    if (!passwordhere.equals(confirmhere)) {
        errorList.add("password and confirm password does not match");
        flag=false;
    }
    if (passwordhere.length() < 8) {
        errorList.add("Password lenght must have alleast 8 character !!");
        flag=false;
    }
    if (!specailCharPatten.matcher(passwordhere).find()) {
        errorList.add("Password must have atleast one specail character !!");
        flag=false;
    }
    if (!UpperCasePatten.matcher(passwordhere).find()) {
        errorList.add("Password must have atleast one uppercase character !!");
        flag=false;
    }
    if (!lowerCasePatten.matcher(passwordhere).find()) {
        errorList.add("Password must have atleast one lowercase character !!");
        flag=false;
    }
    if (!digitCasePatten.matcher(passwordhere).find()) {
        errorList.add("Password must have atleast one digit character !!");
        flag=false;
    }

    return flag;

}

Answer 2

我不确定为什么当我输出它时输出不会考虑特殊字符并引发错误。

提示：看一下这个片段：

    for (int p = 0; p < passwordhere.length(); p++) {
        if (Character.isUpperCase(passwordhere.charAt(p))) {
        }
    }

当它看到一个大写字符时它做了什么？

提示2：我认为你需要计算各种角色类中的角色然后....

如何让循环告诉用户需要什么才能成为正确的密码？对于上面的示例，它缺少大写字母和符号（*＆amp; ^ .. etc）

提示：你的isValid方法需要＆＃34;告诉＆＃34;某人或某事为什么密码无效。想想它如何做到这一点。（提示2：我可以想到三种不同的方法：异常，返回值，打印）

Answer 3

使用此bean验证库进行密码验证：

https://github.com/ankurpathak/password-validation https://mvnrepository.com/artifact/com.github.ankurpathak.password/password-validation

它提供了许多约束来处理密码验证，还有更多将在不久的将来添加：

ContainDigit：验证密码是否包含指定位数。
ContainLowercase：用于验证密码是否包含指定数量的小写字母。
ContainSpecial：用于验证密码是否包含指定数量的特殊符号。
ContainUppercase：验证密码是否包含指定数量的大写字母。
NotContainWhitespace：要验证，不应有任何空格。
PasswordMatches：用于验证密码和确认密码是否相等。你可以移动还通过使用标志showErrorOnConfirmPassword移动约束以确认密码字段（默认为true）。

默认情况下，所有约束都忽略空白，以便由NotBlank单独报告标准bean验证约束，我们可以使用ignoreBlank（默认为true）转为相同约束每个约束的标志。

使用该库的小例子是：


    @PasswordMatches
    public class PasswordDto {
     @Size(min = 8, max = 30)
     @NotContainWhitespace
     @ContainSpecial
     @ContainDigit
     private String password;
     @NotBlank
     private String confirmPassword;
    }

Answer 4

import javax.swing.JOptionPane;

public class Validation {   

static String password;

public static boolean IsValidInput(String s) {

 boolean status = false;    
 char [] array = s.toCharArray();
 int lower=0, upper=0, digits=0;

 if (s.length() > 8) 
 status = true;

  for ( int i = 0;  i < array.length; i++) {
   if(Character.isDigit(array[i]))
      digits++;
   if(Character.isLowerCase(array[i]))
      lower++;
   if(Character.isUpperCase(array[i]))
      upper++;
 }

   if ( !(lower  > 0 ))
   status = false;

   if ( !(upper  > 0 ))
   status = false;

   if ( !(digits > 0 ))
   status = false;

   return status;
 }     

 public static void  setPassword(String p) {
 if (IsValidInput(p)) {
  password = p;
 JOptionPane.showMessageDialog( null, " Your Password is accepted -" + p);
 }

 else {
 password ="";
 JOptionPane.showMessageDialog( null, " Your  Password is  not accepted -" + p);
 }
 }

}

Answer 5

您好请检查以下代码，它可能会对您有所帮助

public static void main(String[] args) {

    Scanner in = new Scanner(System.in);
    System.out.print("Please enter a given  password : ");
    String passwordhere = in.nextLine();
    System.out.print("Please re-enter the password to confirm : ");
    String confirmhere = in.nextLine();
    System.out.println("your password is: " + passwordhere);
    List<String> errorList=isValid(passwordhere,confirmhere);
    while (!errorList.isEmpty()) {
        System.out.println("The password entered here  is invalid");
        for(String error : errorList){
            System.out.println(error);
        }
        String Passwordhere = in.nextLine();
        System.out.print("Please re-enter the password to confirm : ");

    }

}

public static List<String> isValid(String passwordhere, String confirmhere) {

    List<String> errorList = new ArrayList<String>();

    Pattern specailCharPatten = Pattern.compile("[^a-z0-9 ]", Pattern.CASE_INSENSITIVE);
    Pattern UpperCasePatten = Pattern.compile("[A-Z ]");
    Pattern lowerCasePatten = Pattern.compile("[a-z ]");
    Pattern digitCasePatten = Pattern.compile("[0-9 ]");

    if (!passwordhere.equals(confirmhere)) {
        errorList.add("password and confirm password does not match");
    }
    if (passwordhere.length() <= 8) {
        errorList.add("Password lenght must have alleast 8 character !!");
    }
    if (!specailCharPatten.matcher(passwordhere).find()) {
        errorList.add("Password must have atleast one specail character !!");
    }
    if (!UpperCasePatten.matcher(passwordhere).find()) {
        errorList.add("Password must have atleast one uppercase character !!");
    }
    if (!lowerCasePatten.matcher(passwordhere).find()) {
        errorList.add("Password must have atleast one lowercase character !!");
    }
    if (!digitCasePatten.matcher(passwordhere).find()) {
        errorList.add("Password must have atleast one digit character !!");
    }

    return errorList;

}

密码验证8位数，包含upper，lowerCase和特殊字符

5 个答案: