title: create an instance of HttpServletResponse to capture response to a buffer
body: <p>I am calling a method the takes a <code>HttpServletResponse</code> object and then writes to the response body. Is there a <code>HttpServletResponse</code> implementation that captures the response to a byte array instead of actually writing/flushing the response to the client making the request (so I can update the content and send it to the HTTP client)? I know I can write my own implimentation using <code>HttpServletResponseWrapper</code> but wanted to see if there are any library/utils that do this already instead of reinventing the wheel. </p>