Mercosul standard vehicle plate?

Question

I’m working on a project and I don’t know how to do it. As in the statement, I need to validate the plates with the Mercosul standard, I have a method to validate the old plates of vehicles.

public boolean validaPlaca(String placa) {
    boolean result = false;

    Pattern pattern = Pattern.compile("[A-Z]{3}-\\d{4}");
    Matcher mat = pattern.matcher(placa);
    if (!mat.matches()) {
        result = false;
    } else {
        result = true;

    }
    return result;

}

Now to validate the standard Mercosur plate do not know how to do. I’ve done:

Pattern pattern = Pattern.compile("[A-Z]{3}\d{1}[A-Z]{3}\d{2}");

And also:

Pattern pattern = Pattern.compile("[A-Z]{3}[0-9][A-Z][0-9]{2}");

None worked, remembering that the Mercosur standard is AAA3B11. The first 3 digits are letters, the fourth is a number, the fifth a letter and the sixth and seventh a number.

Answer 1

Note that your method is validatePlate, therefore should validate the old plates (which will still be in circulation) and also the new plates in the Mercosul model.

So your regex should validate both formats. An expression to validate both formats at the same time would be this: [A-Z]{3}[0-9]{1}[A-Z]{1}[0-9]{2}|[A-Z]{3}[0-9]{4}

But there are still considerations to do, for example, the plate is of the Mercosur standard but each country has a combination of different letters and numbers.

For example:

• Argentina: AB123CD
• Brazil: ABC1D23
• Uruguay: ABC1234
• Paraguay: 123ABCD

In summary, would adopt the same regular expression that the IRS does in the issuance of Electronic Tax Documents (NF-e, CT-e and MDF-e) that is this: [A-Z]{2,3}[0-9]{4}|[A-Z]{3,4}[0-9]{3}|[A-Z0-9]{7}, this way would not be restricted the validation of the plates of Brazil.

Answer 2

Well, from what I can see the second regex that you exemplified is correct "[A-Z]{3}[0-9][A-Z][0-9]{2}".

I believe then that the error is in the function that validates the plate and uses this regex.

Try using the function below to see if it works, so I’ve tested it right here.

public boolean validarPlaca(String placa) {
    boolean placaValida = true;

    if (placa.length() > 0) {
        if (placa.length() < 7) {
            placaValida = false;
        } else {
            if (!placa.matches("[A-Z]{3}[0-9][A-Z][0-9]{2}")) {
                placaValida = false;
            }
        }
    }

    return placaValida;
}

Tip: Use the site Regex101 to check whether or not their regex are right.

Source: Mercosur plate - Alberto Marianno

Answer 3

Follow my check function:

if (txtPlaca.getText().isEmpty()) {
    ValidationFields.checkEmptyFields(txtPlaca);
    Alert dlg = new Alert(AlertType.ERROR);
    dlg.setContentText("Preencha o campo PLACA!!!");
    dlg.showAndWait();
    txtPlaca.requestFocus();
    return;
} else {
    boolean valida = true;
    String validar = txtPlaca.getText();
    System.out.println("validar placa : " + validar);

    if (validaPlaca(validar) == valida || validaPlacaMercosul(validar) == valida) {

    } else {

        Alert dlg = new Alert(AlertType.ERROR);
        dlg.setContentText("Placa digitada não e válida!!!");
        dlg.showAndWait();
        txtPlaca.requestFocus();
        return;
    }

    placa = txtPlaca.getText();

}