Creating a Base64 encoded SHA-256 hash in Java [closed]

Question

We need to read the file contents and convert it into SHA256 and then convert it into Base64.

Any pointer or sample code will suffice , as I am new to this encryption mechanism.

Thanks in advance.

Answer 1

With Java 8 :

public static String fileSha256ToBase64(File file) throws NoSuchAlgorithmException, IOException {
    byte[] data = Files.readAllBytes(file.toPath());
    MessageDigest digester = MessageDigest.getInstance("SHA-256");
    digester.update(data);
    return Base64.getEncoder().encodeToString(digester.digest());
}

BTW : SHA256 is not encryption, it's hashing. Hashing doesn't need a key, encryption does. Encryption can be reversed (using the key), hashing can't. More on Wikipedia : https://en.wikipedia.org/wiki/Hash_function

Answer 2

You can use MessageDigest to convert to SHA256, and Base64 to convert it to Base64:

public static String encode(final String clearText) throws NoSuchAlgorithmException {
    return new String(
            Base64.getEncoder().encode(MessageDigest.getInstance("SHA-256").digest(clearText.getBytes(StandardCharsets.UTF_8))));
}