loginfilter.java

JSP+Mysql的网上订餐,用户有增删改除等功能,订单模块

package 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.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import com.yy.bean.UserBean;
import com.yy.dao.UserDao;

public class LoginFilter implements Filter {

	public void destroy() {
		// TODO Auto-generated method stub
 
	}

	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		HttpServletRequest re=(HttpServletRequest)request;
		HttpServletResponse res=(HttpServletResponse)response;
		HttpSession session=re.getSession();
		if(session.getAttribute("user")==null){
			session.setAttribute("msg", "请先登录");
			res.sendRedirect("login.jsp");
			chain.doFilter(request, response);
		}else{
			chain.doFilter(request, response);
		}
		
	}

	public void init(FilterConfig arg0) throws ServletException {
		// TODO Auto-generated method stub

	}

}