未登录跳转登录页面

package cn.tedu.filter;

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.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import cn.tedu.bean.User;

/**
 * Servlet Filter implementation class CheckLogin
 */
@WebFilter("/web/*")
public class CheckLogin implements Filter {

    /**
     * Default constructor. 
     */
    public CheckLogin() {
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see Filter#destroy()
	 */
	public void destroy() {
		// TODO Auto-generated method stub
	}

	/**
	 * @see Filter#doFilter(ServletRequest, ServletResponse, FilterChain)
	 */
	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
		//1.获取session的user属性值，判断为空的话，说明没登陆过，跳转到login.jsp页面
		//2.不为空,调用doFilter方法
　　　　　　　　　　//强转为httpservletrequest和httpservletresponse
		HttpServletRequest rq=(HttpServletRequest)request;
		HttpServletResponse rp=(HttpServletResponse)response; 
		 User user= (User) rq.getSession().getAttribute("user");
		 if(user==null){
			rp.sendRedirect("/TeduStore/login.jsp");
		 }
		
		chain.doFilter(rq, response);
	}

	/**
	 * @see Filter#init(FilterConfig)
	 */
	public void init(FilterConfig fConfig) throws ServletException {
		// TODO Auto-generated method stub
	}

}