Is it possible to change plain socket to SSLSocket?

Question

There is a plain socket server listening on port 12345;

ServerSocket s = new ServerSocket(12345);

What I want to know is that

Answer 1

The Socket/SSLSocket interface does not allow convenient content-recognition here - when you start reading from a socket and see that it is only garbage (not plain HTTP), you can't supply this data to a new SSLSocket wrapped around a normal one.

You could use a Socket (or SocketChannel) and look at the data, and then (if it is not the start of a plain HTTP request) pass the same data to an SSLEngine object for decryption/encryption. This means that you have to handle all the encryption/decryption calls yourself, which is not totally trivial (at least, it is a lot more complicated than simply using an SSLSocket with it's two streams - I did it once).

Of course, if you do this, you would likely better implement the RFC 2817 interface, instead of trying automated content sniffing.