Get MD5 String from Message Digest

Question

I understand how it works but if I want to print out the MD5 as String how would I do that?

public static void getMD5(String fileName) throws Exception{
            


        

Answer 1

/**
 * hashes:
 * e7cfa2be5969e235138356a54bad7fc4
 * 3c9ec110aa171b57bb41fc761130822c
 *
 * compiled with java 8 - 12 Dec 2015
 */
public static String generateHash() {
    long r = new java.util.Random().nextLong();
    String input = String.valueOf(r);
    String md5 = null;

    try {
        java.security.MessageDigest digest = java.security.MessageDigest.getInstance("MD5");
        //Update input string in message digest
        digest.update(input.getBytes(), 0, input.length());
        //Converts message digest value in base 16 (hex)
        md5 = new java.math.BigInteger(1, digest.digest()).toString(16);
    }
    catch (java.security.NoSuchAlgorithmException e) {
        e.printStackTrace();
    }
    return md5;
}

Answer 2

With the byte array, result from message digest:

...
byte hashgerado[] = md.digest(entrada);
...

for(byte b : hashgerado)
    System.out.printf("%02x", Byte.toUnsignedInt(b));

Result (for example):
89e8a9f68ad3c4bba9b9d3581cf5201d

Answer 3

You can get it writing less:

String hex = (new HexBinaryAdapter()).marshal(md5.digest(YOUR_STRING.getBytes()))

Answer 4

Try this

StringBuffer hexString = new StringBuffer();
MessageDigest md = MessageDigest.getInstance("MD5");
byte[] hash = md.digest();

for (int i = 0; i < hash.length; i++) {
    if ((0xff & hash[i]) < 0x10) {
        hexString.append("0"
                + Integer.toHexString((0xFF & hash[i])));
    } else {
        hexString.append(Integer.toHexString(0xFF & hash[i]));
    }
}

Answer 5

Shortest way:

String toMD5(String input) {
    MessageDigest md = MessageDigest.getInstance("MD5");
    byte[] raw = md.digest(input.getBytes());
    return DatatypeConverter.printHexBinary(raw);
}

Just remember to handle the exception.