Serve a request with post method in java

I'm developing a web server in java using ServerSocket.

But I have some issues I can't address them, I do not how, I've been stuck for a long time.

The first one is:

When I make a post petition using a form from Chrome. Im reading in the server something like:

POST /something.htm HTTP/1.1 List of headers CRLF ítem=value

When I finish of read all the header, comes 'CRLF', but happend 2 things.

1.chrome waits that I send a response with the page.

2.I wait to read the CRLF to start to read the 'mesage body' with the content "ítem=value"



Thus and as you can imagine my App stay there for a long time, waiting for a stream.

I mean I can not read the "messagge body". I can just if I send a response with a new page.

But this make me feel confused, because should I not read everythig? instead of read until the CRLF?

The protocol doest say that I have to read until the CRLF, send a response from the server and then read the message body.

This web server is a practice of school.

The profesor told us that we need provide GET and POST methods.

I've been reading and I found that when we use POST we need to use a CGI (commong gateway interface)

Here comes my second issue.

I need to use CGI? and probably this is why Im having troubles reading the message body? Or I can In some way use jsp?

Sorry if my my cuestion is dumb.

If there are some references you know, where you feel I need to accomplish my task I will be very grateful.