private static boolean basicNumberCheck(ByteBuffer buffer) {
        byte firstByte = buffer.get(0);
        return (firstByte >= '0' && firstByte <= '9') || firstByte == '+' || firstByte == '-' || firstByte == '.';
    }
A fast json deserializer which parse json in utf-8 encoding bytes directly.
Using this class to avoid the pay-off of transforming into utf-16 (i.e. java String), and generating lots of intermediate objects.
It supports multiple json objects, seperated by comma, and each object can only contains one layer. e.g.
<pre>
{"name": "Flow", "score": 4.3}, {"title": "You know \"nothing\"! Jon Snow."}
</pre>
indexr-common/src/main/java/io/indexr/util/UTF8JsonDeserializer.java