This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
Sounds like the sort of thing covered in the API, did you check?
Joined: Jul 04, 2004
From the API..
public void addHeader(java.lang.String name, java.lang.String value) Adds a response header with the given name and value. This method allows response headers to have multiple values. Parameters: name - the name of the header value - the additional header value