Regular expression for Java (validating password)

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Regular expression for Java (validating password)

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#1 by (3 votes)

2

I need a regular expression to validate the following password:

The password must contain at least one element of each :

More than 6 characters;

Uppercase and lowercase letters;

Numbers;

Special characters.

Currently, I have this:

if(senha.matches("(^|$)[a-z]+(^|$)[0-9]")) {
    JOptionPane.showMessageDialog(null, senha.matches("(^|$)[a-z]+(^|$)[0-9]"));
}

else {
    JOptionPane.showMessageDialog(null, senha.matches("(^|$)[a-z]+(^|$)[0-9]"));
}

java regex

asked by anonymous 30.09.2017 / 20:33

1 answer

Stored Procedure with if Query mysql to get data from two rows and join in just one

score 3 · Accepted Answer

Does it have to be regular expression? I ask this because determining that using regular expression is needed seems to me to be a case of XY problem .

If using regular expressions is not required, you can do this:

public static boolean senhaForte(String senha) {
    if (senha.length() < 6) return false;

    boolean achouNumero = false;
    boolean achouMaiuscula = false;
    boolean achouMinuscula = false;
    boolean achouSimbolo = false;
    for (char c : senha.toCharArray()) {
         if (c >= '0' && c <= '9') {
             achouNumero = true;
         } else if (c >= 'A' && c <= 'Z') {
             achouMaiuscula = true;
         } else if (c >= 'a' && c <= 'z') {
             achouMinuscula = true;
         } else {
             achouSimbolo = true;
         }
    }
    return achouNumero && achouMaiuscula && achouMinuscula && achouSimbolo;
}

And this still has the advantage that if you need to change the criteria of what is considered a strong password, it is much easier to tweak it than in a regular expression.