myfilter.java

the article is about JAVA

package com.wang.servlet;

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;

/*
过滤器servlet 用于判断用户是否登陆成功
*/

public class MyFilter extends HttpServlet implements Filter {
    private FilterConfig filterConfig;
    public void init(FilterConfig filterConfig) throws ServletException {
        this.filterConfig = filterConfig;
    }
    public void doFilter(ServletRequest request, ServletResponse response,
                         FilterChain filterChain) {
        HttpServletRequest request1=(HttpServletRequest)request;
                HttpServletResponse response1=(HttpServletResponse)response;
                try
                {
                   request.setCharacterEncoding("GBK");
                   String url= request1.getRequestURI();

                   com.wang.bean.UserBean ub=(com.wang.bean.UserBean)(request1.getSession().getAttribute("user"));
                   if(ub==null)
                   {

                       if(url.indexOf("login.jsp")!=-1||url.indexOf("checkservlet")!=-1||url.indexOf("reg.jsp")!=-1||url.indexOf("regservlet")!=-1)
                       {
                           filterChain.doFilter(request1, response);

                       }else
                       {
                            response1.sendRedirect("/web/login.jsp");
                       }
                   }else
                    filterChain.doFilter(request1, response1);
                }
                catch (Exception ex)
                {
                    ex.printStackTrace();
                }

    }
    public void destroy() {
    }
}