小弟我想在filter中统一处理错误。不知道是不是这样写？

 import java.io.IOException;import javax.servlet.Filter;import javax.servlet.FilterChain;import javax.servlet.FilterConfig;import javax.servlet.ServletException;import javax.servlet.ServletRequest;import javax.servlet.ServletResponse;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;public class ExceptionFilter implements Filter {    protected FilterConfig filterConfig = null;    private static final String PAGE_TO_FORWARD = "errorNew.jsp";    // ---------------------- Public Methods    public void doFilter(ServletRequest req, ServletResponse res,            FilterChain chain) throws IOException, ServletException {        HttpServletResponse response = (HttpServletResponse) res;        HttpServletRequest request = (HttpServletRequest) req;        HttpSession session = request.getSession();        Exception e=null;        long millsecds=0;                millsecds=System.currentTimeMillis();                try {            chain.doFilter(req, res);        }catch(NullPointerException ee){                        e=ee;            session.setAttribute("msg", "空指针异常!异常编号是:"+millsecds);        } catch (Exception ee) {            e=ee;            session.setAttribute("msg", "异常!异常编号是:"+millsecds);                    }        //把异常信息保存到        saveExceptionToDataBase(e,millsecds);        session.setAttribute("e", e);        redirect(PAGE_TO_FORWARD, request, response);    }    public void init(FilterConfig filterConfig) {    }    public void destroy() {    }    // --------------------- Private Methods    private void redirect(String page, HttpServletRequest request,            HttpServletResponse response) throws ServletException, IOException {        response.sendRedirect(request.getContextPath() + "/" + page);    }    private void saveExceptionToDataBase(Exception e,long millsecds){        //把异常保存到db中    }}