Question

I’m using an ObjectOutputStream over my socket because I created a new class that needs to be transported between the client and the server.
I also created a unique thread that sends one byte every one second over the stream to the server in order to inspect the connection continuously and check that its alive.

byte b=1;
oos.writeObject(b);

I use “byte” because it is the smallest object that I can send (right?) so that the server will not read longer objects.

My question is if the server reads one byte object (size of byte) or an 8 byte object (the size of an object)
?

Answer 1

Probably neither. First, a byte is autoboxed into a Byte. Then the Byte is serialized to your output stream. It probably takes quite a bit more than 8 bytes to send. I don’t know the spec exactly, but it probably sends the class name java.lang.Byte and the byte itself, plus probably a few more control bytes.

An easy way to tell – serialize your byte to a ByteArrayOutputStream, flush your ObjectOutputStream, then see how many bytes your ByteArrayOutputStream ends up with.