sample java app

test.java

 import java.security.MessageDigest;
 public class Main
{
	public static void main(String[] args) {
		System.out.println(hexStringToByteArray(sha256("badge1")));
		System.out.println("-------");
		
			System.out.println(byteArrayToHexString(hexStringToByteArray(sha256("badge1"))));
						System.out.println(byteArrayToHexString(hexStringToByteArray(sha256("badge1"))));

 	}
 	private static String hexToAscii(String hexStr) {
    StringBuilder output = new StringBuilder("");
     
    for (int i = 0; i < hexStr.length(); i += 2) {
        String str = hexStr.substring(i, i + 2);
        output.append((char) Integer.parseInt(str, 16));
    }
     
    return output.toString();
}
 	
	public static byte[] hexStringToByteArray(String s) {
        int len = s.length();
        byte[] data = new byte[len / 2];
        for (int i = 0; i < len; i += 2) {
            data[i / 2] = (byte) ((Character.digit(s.charAt(i), 16) << 4)
                    + Character.digit(s.charAt(i + 1), 16));
        }
        return data;
    }

	public static String sha256(String base) {
        try {
            MessageDigest digest = MessageDigest.getInstance("SHA-256");
            byte[] hash = digest.digest(base.getBytes("UTF-8"));
            StringBuffer hexString = new StringBuffer();

            for (int i = 0; i < hash.length; i++) {
                String hex = Integer.toHexString(0xff & hash[i]);
                if (hex.length() == 1) hexString.append('0');
                hexString.append(hex);
            }

            return hexString.toString();
        } catch (Exception ex) {
            throw new RuntimeException(ex);
        }
    }
    
    
    public static String byteArrayToHexString(byte[] bytes) {
        char[] hexArray = "0123456789ABCDEF".toCharArray();
        char[] hexChars = new char[bytes.length * 2];
        for (int j = 0; j < bytes.length; j++) {
            int v = bytes[j] & 0xFF;
            hexChars[j * 2] = hexArray[v >>> 4];
            hexChars[j * 2 + 1] = hexArray[v & 0x0F];
        }
        return new String(hexChars);
    }

    
}