This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
Normally all the useful headers have a corresponding setter methods already defined in the HttpServletResponse class. For example to set the content type you have HttpServletResponse.setContentType, for setting cookies you have HttpServletResponse.addCookie.
So normally you will not need to use HttpServletResponse.setXxxHeader() methods.