Question

I have two CNAME-s pointed to the same server. I want to assign one servlet to the first CNAME and another one to the second CNAME. Can I do it in web.xml (or somehow else without manual parsing of ServletRequest)?

Answer 1

One of the idea to have a filter, and in it have a condition based on ServletRequest#getServerName() and dispatch the request to appropriate servlet, will do.

public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) 
throws IOException, ServletException {
    ...
    [other processing/validations]
    ...
    if(request.getServerName().equals("domain1.com"))
      request.getRequestDispatcher("/servlet1").forward(request, response)
    else
      request.getRequestDispatcher("/servlet2").forward(request, response)

}

obviously, you could have <init-param> in your web.xml to dynamically set the domains, so that you could change these values based on your build profile.