Another problem to add:

it's complaining about not having a constructor for HttpURLConnection in
my class that extends it, yet when I create a constructor it complains
that it doesn't have a return type...

Can a constructor even have a return type?

No, you do *not* need to implement these methods.
When you open a connection to an URL (http://...), probably by
 url.openConnection();
you do *not* get an object of the abstract java.net.HttpURLConnection class
(the one whose documentation you've read) as such.
Instead you get an object of some non-abstract *subclass* of
java.net.HttpURLConnection, may be an object of class
sun.net.www.protocol.http.IDontKnowWhatConnection. Exactly what class you
get, you don't know and you don't need to know. Because this class is a
non-abstract class, it *has* implementations for all methods declared in
java.net.HttpURLConnection, including usingProxy() and disconnect().
Actually the non-abstract class will override *many* methods of
java.net.HttpURLConnection, not only the abstract ones.
 

The key is to understand polymorphism. That means, when you have a method
 SomeObject someMethod();
then you do *not* necessarily get an object of SomeObjecta s such, but you
may get an object of any subclass of SomeObject. Consider for example:
 SomeObject someMethod() {
   return new SomeSpecializedObject(...);
 }
with the class implementation
 class SomeSpecializedObject extends SomeObject {
   ...
 }

URL url = new URL("http://host/resource");
HttpURLConnection con = (HttpURLConnection) url.openConnection();
int response = con.getResponseCode();

No you don't need to do that. What you do seem to need however is to
read up on how to use the Java API. There are plenty of good books out
there and you can even get some of it for free, like the Sun Java
tutorials:

http://java.sun.com/docs/books/tutorial/index.html
http://java.sun.com/docs/books/tutorial/networking/urls/index.html

and of course the Java API documentation itself

http://java.sun.com/j2se/1.5.0/docs/api/ or
http://java.sun.com/j2se/1.4.2/docs/api/

Regards,