Java - Comment convertir des octets en hexadécimal
En Java, vous pouvez utiliserString.format("%02x", bytes) pour convertir facilement des octets en hexadécimal.
private static String bytesToHex(byte[] hashInBytes) {
StringBuilder sb = new StringBuilder();
for (byte b : hashInBytes) {
sb.append(String.format("%02x", b));
}
return sb.toString();
}
Solution alternative.
private static String bytesToHex1(byte[] hashInBytes) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < hashInBytes.length; i++) {
sb.append(Integer.toString((hashInBytes[i] & 0xff) + 0x100, 16).substring(1));
}
return sb.toString();
}
private static String bytesToHex2(byte[] hashInBytes) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < hashInBytes.length; i++) {
String hex = Integer.toHexString(0xff & hashInBytes[i]);
if (hex.length() == 1) sb.append('0');
sb.append(hex);
}
return sb.toString();
}
1. Octets à hexadécimal - SHA-256
Un exemple Java complet pour utiliser un algorithme SHA-256 pour hacher un mot de passe.
ByesToHex.java
package com.example.hashing;
import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
public class ByesToHex {
public static void main(String[] args) throws NoSuchAlgorithmException {
String password = "123456";
MessageDigest md = MessageDigest.getInstance("SHA-256");
byte[] hashInBytes = md.digest(password.getBytes(StandardCharsets.UTF_8));
System.out.println(bytesToHex(hashInBytes));
System.out.println(bytesToHex2(hashInBytes));
System.out.println(bytesToHex3(hashInBytes));
}
private static String bytesToHex(byte[] hashInBytes) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < hashInBytes.length; i++) {
sb.append(Integer.toString((hashInBytes[i] & 0xff) + 0x100, 16).substring(1));
}
return sb.toString();
}
private static String bytesToHex2(byte[] hashInBytes) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < hashInBytes.length; i++) {
String hex = Integer.toHexString(0xff & hashInBytes[i]);
if (hex.length() == 1) sb.append('0');
sb.append(hex);
}
return sb.toString();
}
private static String bytesToHex3(byte[] hashInBytes) {
StringBuilder sb = new StringBuilder();
for (byte b : hashInBytes) {
sb.append(String.format("%02x", b));
}
return sb.toString();
}
}
Sortie
8d969eef6ecad3c29a3a629280e686cf0c3f5d5a86aff3ca12020c923adc6c92 8d969eef6ecad3c29a3a629280e686cf0c3f5d5a86aff3ca12020c923adc6c92 8d969eef6ecad3c29a3a629280e686cf0c3f5d5a86aff3ca12020c923adc6c92