Can Java omit sending some headers in HTTP requests?

Question

I'm using the HttpConnection class in Java to send HTTP requests.
How do I omit unwanted HTTP headers? like:

• User-Agent
• Accept
• Accept-Language
• Accept-Encoding
• Accept-Charset
• Keep-Alive
• Connection
• Referer
• If-Modified-Since

Answer 1

Yes, setRequestProperty in URLConnection

import java.net.URL;
import java.net.URLConnection;
URL url = new URL("http://www.example.com");
URLConnection urlc = url.openConnection();
urlc.setRequestProperty("User-Agent", null);

Answer 2

If you are talking about HttpURLConnection, you can't do it. Once the header is set, it can't be removed.

Setting header to null or empty doesn't work. I tried this before on Java 5, it resulted invalid HTTP headers, like

Content-Type: text/html
User-Agent
Content-Length: 123