hashes.java

public class Test
{

  private static final String MD5 = "MD5";
  private static final String UTF_8 = "UTF-8";

  public static void main(String[] args) throws Exception
  {
    String email = "example@gmail.com";
    
    byte[] digestBytes = hash(email);
    System.out.println(digestBytes.length);
    System.out.println(Arrays.toString(digestBytes));
    String hexa = bytesToHexa(digestBytes);
    byte[] hexaBytes = hexa.getBytes("UTF-8");
    System.out.println(hexa.length());
    System.out.println(Arrays.toString(hexaBytes));
  }

  private static String bytesToHexa(byte[] digest)
  {
    StringBuffer hexString = new StringBuffer();
    for (int i = 0; i < digest.length; i++)
    {
      hexString.append(Integer.toHexString(0xFF & digest[i]));
    }
    return hexString.toString();
  }

  private static byte[] hash(String email) throws Exception
  {
    byte[] bytes = email.getBytes(UTF_8);
    MessageDigest md = MessageDigest.getInstance(MD5);
    return md.digest(bytes);
  }
}