public static byte[] decode(String input) {

        // Check special case
        if (input == null || input.equals("")) {
            return new byte[0];
        }
        char[] sArr = input.toCharArray();
        int sLen = sArr.length;
        if (sLen == 0) {
            return new byte[0];
        }

        int sIx = 0;
        // Start and end index after trimming.
        int eIx = sLen - 1;

        // Trim illegal chars from start
        while (sIx < eIx && IALPHABET[sArr[sIx]] < 0) {
            sIx++;
        }

        // Trim illegal chars from end
        while (eIx > 0 && IALPHABET[sArr[eIx]] < 0) {
            eIx--;
        }

        // get the padding count (=) (0, 1 or 2)
        // Count '=' at end.
        int pad = sArr[eIx] == '=' ? (sArr[eIx - 1] == '=' ? 2 : 1) : 0;
        // Content count including possible separators
        int cCnt = eIx - sIx + 1;
        int sepCnt = sLen > 76 ? (sArr[76] == '\r' ? cCnt / 78 : 0) << 1 : 0;
        // The number of decoded bytes
        int len = ((cCnt - sepCnt) * 6 >> 3) - pad;
        // Preallocate byte[] of exact length
        byte[] dArr = new byte[len];

        // Decode all but the last 0 - 2 bytes.
        int d = 0;
        int three = 3;
        int eight = 8;
        for (int cc = 0, eLen = (len / three) * three; d < eLen; ) {

            // Assemble three bytes into an int from four "valid" characters.
            int i = ctoi(sArr[sIx++]) << 18 | ctoi(sArr[sIx++]) << 12 | ctoi(sArr[sIx++]) << 6 | ctoi(sArr[sIx++]);

            // Add the bytes
            dArr[d++] = (byte) (i >> 16);
            dArr[d++] = (byte) (i >> 8);
            dArr[d++] = (byte) i;

            // If line separator, jump over it.
            if (sepCnt > 0 && ++cc == 19) {
                sIx += 2;
                cc = 0;
            }
        }

        if (d < len) {
            // Decode last 1-3 bytes (incl '=') into 1-3 bytes
            int i = 0;
            for (int j = 0; sIx <= eIx - pad; j++) {
                i |= ctoi(sArr[sIx++]) << (18 - j * 6);
            }

            for (int r = 16; d < len; r -= eight) {
                dArr[d++] = (byte) (i >> r);
            }
        }

        return dArr;
    }
@Test
    void testStandardDecode() {
        String origin = "aGVsbG8sbmFjb3MhdGVzdEJhc2U2NGVuY29kZQ==";
        String expectDecodeOrigin = "hello,nacos!testBase64encode";
        byte[] decodeOrigin = Base64Decode.decode(origin);
        assertArrayEquals(decodeOrigin, expectDecodeOrigin.getBytes());
    }