private byte[] bytesToHex(byte[] bytes) {
		byte[] hexChars = new byte[bytes.length * 2];
		for (int j = 0; j < bytes.length; j++) {
			int v = bytes[j] & 0xFF;
			hexChars[j * 2] = HEX_DIGITS[v >>> 4];
			hexChars[j * 2 + 1] = HEX_DIGITS[v & 0x0F];
		}
		return hexChars;
	}
Whether to attempt to create the directory structure at startup (disable for read-only implementations).
spring-xd-dirt/src/main/java/org/springframework/xd/dirt/module/WritableResourceModuleRegistry.java