如何从过滤器中确定哪个页面服务于 RequestDispatcher 的转发？

Question

我有一个过滤器，它处理请求以记录它们，因此我可以使用什么请求参数来跟踪哪个会话在什么时间访问了一个页面。效果很好...从 jsp 发布到 jsp，或直接调用 jsp。但是，当一个表单被发布到一个 servlet 时，该 servlet 将该请求转发到一个新的 jsp，但是，我无法看到该请求被转发到了哪个 jsp。

例如，假设我有一个登录页面，它发布到 LoginServlet，然后将请求转发到 index.jsp 或 index1.jsp。如何从请求中确定 LoginServlet 是返回 index.jsp 还是 index1.jsp？

这是在使用 2.3 servlet 规范的 java 1.5 环境中。

public class PageLogFilter implements Filter {

FilterConfig filterConfig = null;
public void init(FilterConfig filterConfig) throws ServletException {
    this.filterConfig = filterConfig;
}
public void destroy() {
    this.filterConfig = null;
}

public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
    throws IOException, ServletException {
    try {
        if (request instanceof HttpServletRequest) {
            HttpServletRequest req = (HttpServletRequest) request;
            HttpSession session = req.getSession(false);

                //For non-forwards, I can call req.getRequestURI() to determine which 
                //page was returned. For forwards, it returns me the URI of the  
                //servlet which processed the post. I'd like to also get the URI
                //of the jsp to which the request was forwarded by the servlet
            }
        }
    } catch (Exception e) {
        System.out.println("-- ERROR IN PageLogFilter: " + e.getLocalizedMessage());
    }
    chain.doFilter(request, response);
}
}

Answer 1

在chain.doFilter(..)之后调用request.getRequestURI()