Exemple de hachage Java MD5
Dans cet article, nous allons vous montrer comment utiliser unMD5 algorithm pour hacher une chaîne et générer une somme de contrôle pour un fichier.
1. MessageDigest
1.1 MD5 to Hash a string.
PasswordMD5.java
package com.example.hashing;
import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
public class PasswordMD5 {
public static void main(String[] args) throws NoSuchAlgorithmException {
String password = "123456";
MessageDigest md = MessageDigest.getInstance("MD5");
byte[] hashInBytes = md.digest(password.getBytes(StandardCharsets.UTF_8));
StringBuilder sb = new StringBuilder();
for (byte b : hashInBytes) {
sb.append(String.format("%02x", b));
}
System.out.println(sb.toString());
}
}
Sortie
e10adc3949ba59abbe56e057f20f883e
1.2 File checksum.
d:\server.log
123456
FileCheckSum.java
package com.example.hashing;
import java.io.FileInputStream;
import java.io.IOException;
import java.security.DigestInputStream;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
public class FileCheckSum {
public static void main(String[] args) throws NoSuchAlgorithmException, IOException {
MessageDigest md = MessageDigest.getInstance("MD5");
byte[] hashInBytes = checksum("d:\\server.log", md);
System.out.println(bytesToHex(hashInBytes));
}
private static byte[] checksum(String filepath, MessageDigest md) throws IOException {
try (DigestInputStream dis = new DigestInputStream(new FileInputStream(filepath), md)) {
while (dis.read() != -1) ; //empty loop to clear the data
md = dis.getMessageDigest();
}
return md.digest();
}
private static String bytesToHex(byte[] hashInBytes) {
StringBuilder sb = new StringBuilder();
for (byte b : hashInBytes) {
sb.append(String.format("%02x", b));
}
return sb.toString();
}
}
Sortie
e10adc3949ba59abbe56e057f20f883e
2. Codec Apache Commons
Sinon, essayez cette bibliothèqueApache Commons Codecs pour le hachage.
pom.xml
commons-codec commons-codec 1.11
2.1 Hash a String.
PasswordMD5.java
package com.example.hashing;
import org.apache.commons.codec.digest.DigestUtils;
public class PasswordMD5 {
public static void main(String[] args) {
String password = "123456";
String result = DigestUtils.md5Hex(password);
System.out.println(result);
}
}
Sortie
e10adc3949ba59abbe56e057f20f883e
2.2 File checksum.
FileCheckSum.java
package com.example.hashing;
import org.apache.commons.codec.digest.DigestUtils;
import java.io.FileInputStream;
import java.io.IOException;
public class FileCheckSum {
public static void main(String[] args) throws IOException {
String result = DigestUtils.md5Hex(new FileInputStream("d:\\server.log"));
System.out.println(result);
}
}
Sortie
e10adc3949ba59abbe56e057f20f883e