密码的Java Regex表达式

Question

I've just created this class for a password validation

 /* 
 *  ^                         Start anchor
 *  (?=.*[A-Z].*[A-Z])        Ensure string has two uppercase letters.
 *  (?=.*[!@#$&*])            Ensure string has one special case letter.
 *  (?=.*[0-9].*[0-9])        Ensure string has two digits.
 *  (?=.*[a-z].*[a-z].*[a-z]) Ensure string has three lowercase letters.
 *  .{8}                      Ensure string is of length 8.
 *  $                         End anchor.
 */
public class PasswordUtils {

    private static final String PWD_REGEX = "^(?=.*[A-Z].*[A-Z])(?=.*[!@#$&*])(?=.*[0-9].*[0-9])(?=.*[a-z].*[a-z].*[a-z])";

    /**
     * Non instantiable.
     */
    private PasswordUtils() {
        throw new AssertionError("Non instantiable");
    }

    public static boolean match (String pwd1, String pwd2) {
        return StringUtils.equals(pwd1, pwd2);
    }

    public static boolean isStrong(String password){
        return password.matches(PWD_REGEX);
     }
}

Then this Junit, but it seems that the pwd does not match the requirements of the regular expression

private final String PWD6 = "Pi89pR&s";

@Test
public void testStrong () {
    assertTrue(PasswordUtils.isStrong(PWD6));
}

Answer 1

Try this:

(?=(?:.*[AZ]){2})(?=(?:.*[az]){2})(?=(?:.*[0-9]){2})(?=(?:.*[!@#$&*]){1}).{8}

The basic idea is:

(?=(?:.*[GROUP]){NUMBER})

Where GROUP is the grouping you want to match (ie AZ ) and NUMBER is how many.

Also note, you can use {NUMBER,} if you want to match NUMBER or more occurrences of each group.

https://regex101.com/r/JGtIkF/1

Answer 2

Try this hope this will help you out..

Regex: ^(?=.*?[AZ].*?[AZ])(?=.*?[az].*?[az].*?[az])(?=.*?[\\d].*?[\\d])(?=.*?[^\\w]).{8}$

1. ^ start of string.

2. (?=.*?[AZ].*?[AZ]) positive look ahead for two uppercase characters.

3. (?=.*?[az].*?[az].*?[az]) positive look ahead for three lowercase characters.

4. (?=.*?[\\d].*?[\\d]) positive look ahead for two digits.

5. (?=.*?[^\\w]) positive look ahead for non-word character

6. .{8} will match exactly 8 characters.

7. $ end of string.

Regex code demo