What things should be kept in mind while desigining an HTTP based protocol?

Question

I have heard that http is a nice way to design my own protocol. although i can design a binary protocol, i would prefer to follow the HTTP standard to design my protocol. basically the flow of the application is that with the request the client sends some parameter strings to the server, the server sends the response string to the application. this procedure continues several times, before the connection thread terminates.

i am using java servlets for the above. how should the client send the HTTP parameters so that parsing is easy at the server.

Get /a HTTP/1.1
Host: localhost

??? what comes here

Answer 1

??? what comes here

Since that is a GET request, nothing.

I'd suggest using querystring parameters, then you can access them using ServletRequest.getParameterNames(), getParameterValues(), getParameterMap() etc.

So, your request line would take the form:

GET /a?x=1&y=1 HTTP/1.1

since this is the standard way of passing parameter data, other clients, such as web browsers, will be able to use your service easily.

This assumes that the operation does not cause side-effects on the server. If it does then you should be using a POST, PUT or DELETE request depending on the exact nature of the operation.

HTTP Made Really Easy is a useful document since, at least initially, the HTTP Spec can be a bit daunting.

Answer 2

What you're designing is a data exchange format, not a protocol really.

So the question is, really, what sort of data do you want to send? To answer that, you need to consider who is receiving it. If it's yourself, then just keep it simple.

Answer 3

Why not base your protocol on something that already exists for example SOAP?