十六进制的字符串转十六进制

 private static byte[] hexToBytes(String hexString) {
        if (TextUtils.isEmpty(hexString))
            throw new IllegalArgumentException("this hexString must not be empty");

        hexString = hexString.toLowerCase();
        final byte[] byteArray = new byte[hexString.length() / 2];
        int k = 0;
        for (int i = 0; i < byteArray.length; i++) {//因为是16进制，最多只会占用4位，转换成字节需要两个16进制的字符，高位在先
            byte high = (byte) (Character.digit(hexString.charAt(k), 16) & 0xff);
            byte low = (byte) (Character.digit(hexString.charAt(k + 1), 16) & 0xff);
            byteArray[i] = (byte) (high << 4 | low);
            k += 2;
        }
        return byteArray;
    }

下面是一个十六进制的字符串： 

643e22e00600000000000000026de45b6e00000000000000000000000000005ba9d1e05d8a3d8000000000000000032ec0838500000000000000000000000000005baaee595d8b8f0000000000000000042ec0825900000000000000000000000000005baaee595d8b8f0000000000000000055b5a810c00000000000000000000000000005ba9d2245d8a3d8000000000000000062ec0d07900000000000000000000000000005baaee595d8b8f00

转为为16进制保存到文本结果如下：

AC0CD4643E22E0062020202020202018
04ACD9D7202020202020202020202020
20205BACAE955D8CE080202020202020
201904ACD9D920202020202020202020
202020205BACAEA55D8CE08020202020
2020201A04ACD9D62020202020202020
2020202020205BACAE715D8CE0802020
20202020201B0162072F202020202020
20202020202020205BADEFF95D8E3220
202020202020201C04ACD9D520202020
202020202020202020205BACAE605D8C
E080202020202020201D1AE397EF2020
2020202020202020202020205BA9E2DC
5D8A3D80