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@adrianoluis
Last active November 3, 2025 19:33
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Utility class to validate CPF and CNPJ document types. For CPF use isValidSsn and for CNPJ use isValidTfn. Added to repo https://github.com/adrianoluis/misc-tools
public class DocumentUtil {
// CPF
private static final int[] WEIGHT_SSN = {11, 10, 9, 8, 7, 6, 5, 4, 3, 2};
// CNPJ
private static final int[] WEIGHT_TFN = {6, 5, 4, 3, 2, 9, 8, 7, 6, 5, 4, 3, 2};
private static int sum(int[] weight, char[] numbers, int length) {
if (length <= 0) return 0;
final int nIdx = length - 1;
final int wIdx = weight.length > numbers.length ? length : nIdx;
return (sum(weight, numbers, nIdx) + Character.getNumericValue(numbers[nIdx]) * weight[wIdx]);
}
private static int calculate(final String document, final int[] weight) {
final char[] numbers = document.toCharArray();
int sum = sum(weight, numbers, numbers.length);
sum = 11 - (sum % 11);
return sum > 9 ? 0 : sum;
}
private static boolean check(String tfn, int length, int[] weight) {
final String number = tfn.substring(0, length);
final int digit1 = calculate(number, weight);
final int digit2 = calculate(number + digit1, weight);
return tfn.equals(number + digit1 + digit2);
}
/**
* Valida CPF
*/
public static boolean isValidSsn(String ssn) {
if (ssn == null || !ssn.matches("\\d{11}") || ssn.matches(ssn.charAt(0) + "{11}")) return false;
return check(ssn, 9, WEIGHT_SSN);
}
/**
* Valida CNPJ
*/
public static boolean isValidTfn(String tfn) {
if (tfn == null || !tfn.matches("\\d{14}")) return false;
return check(tfn, 12, WEIGHT_TFN);
}
}
@gleds3000
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Muito bom, obrigado por compartilhar!

@williamartins02
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Obrigado Guerrero, me ajudou muito no projeto do Nélio Alves.

@RicardoTSilva2303
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Muito obrigado Luis, me ajudou bastante.

@piresalexsandro
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Obrigado!!!

@gogaoliveira
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@angelosuporte
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Obrigado

@PortelaVictor
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Obrigado Luis, ajudou bastante.

@jrsguitar
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Muito obrigado!

@Pedrolaires
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Até hoje ajudando muita gente, obrigado!

@newtonneto
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Muito obrigado

@charllysonsouza
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charllysonsouza commented Jan 22, 2022

Obrigado! Estou vindo pelo curso do Nélio da Udemy. Valeu!

@lissa-sonoda
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Muito obrigada, Luis!! Ajudou demais!!

@marland-tales
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Tks bro!

@MarcioGomes78
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Obrigado em ajudar com seu conhecimento um abraço.

@yujiyamamoto64
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Passando pra agradecer tbm!

@allanbarretogaspar
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Passando pra deixar um SUPER obrigado!!!!!!!

@wallisonlemosdev
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Me salvou!

@eymatsuda2016
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Eu também estou fazendo o curso do Prof. Nélio Alves lá na Udemy. Me ajudou e muito. Obrigado pelo código

@Maiav27
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Maiav27 commented Jul 23, 2025

Obrigado amigo , vim pelo Curso do Prof. Nélio Alves

@Franklyn-R-Silva
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