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.
One possible partial work-around is to separate the testing of the fundamental request/response data versus testing the rendered result itself. For example, if you are using Struts then MockStrutsTestCase can be used to see if the data about to be send to the JSP page and the selected forwarding is what you expect. That tells you if everything prior to the final rendering is at least correct.