Encoding with SHA-512

import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Random;

public class Main {
    public static void main(String[] args) {
        String rawPassword = args[0];
        String sault = generateSalt();
        String encodedPassword = encode(sault + rawPassword);
        System.out.println("Sault: " + sault);
        System.out.println("Encoded password: " + encodedPassword);
    }
    
    private static final String DIGEST_ALGORITHM = "SHA-512";
    private static final char[] HEX_ARRAY = "0123456789abcdef".toCharArray();

    public static String encode(CharSequence rawPassword) {
        try {
            MessageDigest md = MessageDigest.getInstance(DIGEST_ALGORITHM);
            byte[] bytes = md.digest(rawPassword.toString().getBytes(StandardCharsets.UTF_8));
            return bytesToHex(bytes);
        } catch (NoSuchAlgorithmException e) {
            throw new RuntimeException("Не удалось получить экземпляр MessageDigest", e);
        }
    }

    public boolean matches(CharSequence rawPassword, String encodedPassword) {
        return encode(rawPassword).equalsIgnoreCase(encodedPassword);
    }

    public static String bytesToHex(byte[] bytes) {
        char[] hexChars = new char[bytes.length * 2];
        for (int j = 0; j < bytes.length; j++) {
            int v = bytes[j] & 0xFF;
            hexChars[j * 2] = HEX_ARRAY[v >>> 4];
            hexChars[j * 2 + 1] = HEX_ARRAY[v & 0x0F];
        }
        return new String(hexChars);
    }

    public static String generateSalt() {
        int leftLimit = 97; // letter 'a'
        int rightLimit = 122; // letter 'z'
        int targetStringLength = 16;
        Random random = new Random();
        StringBuilder buffer = new StringBuilder(targetStringLength);
        for (int i = 0; i < targetStringLength; i++) {
            int randomLimitedInt = leftLimit + (int)
                    (random.nextFloat() * (rightLimit - leftLimit + 1));
            buffer.append((char) randomLimitedInt);
        }
        return buffer.toString();
    }
}