AccessControlFilter

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;

 

 

public class AccessControlFilter implements Filter {

 protected FilterConfig filterConfig = null;

 public void destroy() {

  this.filterConfig = null;

 }

 

 public void doFilter(ServletRequest request, ServletResponse response,
   FilterChain chain) throws IOException, ServletException {
  HttpServletRequest req = (HttpServletRequest)request;
  String url = req.getRequestURI();
  if(url.endsWith("/index.jsp") || url.endsWith("/"))
   chain.doFilter(request, response);
  else {
   boolean validate = false;
         User user;
         if (req.getSession().getAttribute("user") != null) {
             user = (User)req.getSession().getAttribute("user");
             if (user.isLogin()!= null) {
                 validate = true;
             }
         }

   if(!valida) {
    req.getSession().setAttribute("reqUrl", url);
    HttpServletResponse res = (HttpServletResponse)response;
    res.sendRedirect(req.getContextPath()+"/index.jsp");
   } else {
    chain.doFilter(request, response);
   }
  }
 }

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

}