loginfilter.java

该系统的主要功能是

package com.laoniu.web.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.laoniu.bean.Customer;


public class LoginFilter implements Filter {

	public void destroy() {
		
	}

	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		HttpServletRequest req = (HttpServletRequest) request;
		HttpServletResponse res = (HttpServletResponse) response;
		HttpSession session = req.getSession();
		Customer customer = null;
		customer = (Customer) session.getAttribute("customer");
		if (customer == null) {
			res.sendRedirect(req.getContextPath() + "/login.jsp");
		} else {
			chain.doFilter(req, res);
		}
	}

	public void init(FilterConfig arg0) throws ServletException {
	
	}
}