How to get authorization code (code) in Java SDK for VK API?

Question

Java

I study the documentation https://vk.com/dev/Java_SDK
Item 7: This authorization scheme consists of two stages - obtaining an authorization code ("code") and exchanging it for an access key ("access_token"). First you need to get the "code" (instruction) and then do the second step.
Follow the link (instruction) - It is necessary to redirect the user's browser to the address
https://oauth.vk.com/authorize, passing the following parameters (...), of which one parameter is the url-address where the browser will go after successful authorization. Well, actually this very code will be transmitted to this url in the get-parameter.
My problem is that I don't understand how to get this code? Is it even possible to get it in Java? Or do I need to use an HTTPURLConnection to a php file to get it, and in that php file make a transition to oauth and read the get request?