package com.atguigu.javaweb.cache;

import java.io.IOException;

import javax.servlet.FilterChain;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import com.atguigu.javaweb.HttpFilter;

public class NoCacheFilter extends HttpFilter {

    @Override

    public void doFilter(HttpServletRequest request,

            HttpServletResponse response, FilterChain filterChain)

            throws IOException, ServletException {

        System.out.println("cacheFilter's doFilter..");

        //主要是这三个方法：

        response.setDateHeader("Expires",-1);

        response.setHeader("Cache-Control","no-cache");

        response.setHeader("Pragma","no-cache");

        filterChain.doFilter(request, response);

    }

}