java - Handle a POST request and write response to client socket

Question

I am trying to implement a proxy server.

I referred to the information in this blog.

1. The method handles GET request but doesn't handle some websites like www.facebook.com (a GET request). What could be the issue.

2. The method doesn't handle a POST request. How is handling a POST request and writing the response to client socket differ from handling a GET request.

Any pointers or reference links would be helpful.