public static String md5Hex(byte[] bytes) throws NoSuchAlgorithmException {
        try {
            MessageDigest messageDigest = MESSAGE_DIGEST_LOCAL.get();
            if (messageDigest != null) {
                return encodeHexString(messageDigest.digest(bytes));
            }
            throw new NoSuchAlgorithmException("MessageDigest get MD5 instance error");
        } finally {
            MESSAGE_DIGEST_LOCAL.remove();
        }
    }
@Test
    void testMd5Hex() throws NoSuchAlgorithmException {
        assertEquals("d41d8cd98f00b204e9800998ecf8427e", MD5Utils.md5Hex("", Constants.ENCODE));
        assertEquals("acbd18db4cc2f85cedef654fccc4a4d8", MD5Utils.md5Hex("foo", Constants.ENCODE));
        assertEquals("02f463eb799797e2a978fb1a2ae2991e", MD5Utils.md5Hex(
                "38c5ee9532f037a20b93d0f804cf111fca4003e451d09a692d9dea8032308d9c64eda9047fcd5e850284a49b1a0cfb2ecd45",
                Constants.ENCODE));
        
        assertEquals("d41d8cd98f00b204e9800998ecf8427e", MD5Utils.md5Hex(new byte[0]));
        assertEquals("5289df737df57326fcdd22597afb1fac", MD5Utils.md5Hex(new byte[] {1, 2, 3}));
    }