How to use java.net.URLConnection to fire and handle HTTP requests
Use of java.net.URLConnection is asked about pretty often here, and the Oracle tutorial is too concise about it.
That tutorial basically only shows how to fire a GET request and read the response. It doesn't explain anywhere how to use it to, among others, perform a POST request, set request headers, read response headers, deal with cookies, submit a HTML form, upload a file, etc.
So, how can I use java.net.URLConnection to fire and handle "advanced" HTTP requests?