【1】服务端配置一个Filter,实现对js、css和image的缓存
package cn.com.system.filter;import java.io.IOException;import java.util.Enumeration;import javax.servlet.FilterChain;import javax.servlet.FilterConfig;import javax.servlet.ServletException;import javax.servlet.ServletRequest;import javax.servlet.ServletResponse;import javax.servlet.http.HttpServletResponse;public class CacheForWeekFilter { private FilterConfig fc; public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException { HttpServletResponse response = (HttpServletResponse) res; for (Enumeration e = fc.getInitParameterNames(); e.hasMoreElements();) { String headerName = (String) e.nextElement(); response.addHeader(headerName, fc.getInitParameter(headerName)); } chain.doFilter(req, response); } public void init(FilterConfig filterConfig) { this.fc = filterConfig; } public void destroy() { this.fc = null; }}
<filter> <filter-name>CacheForWeek</filter-name> <filter-class>cn.com.system.filter.CacheForWeekFilter</filter-class> <init-param> <param-name>Cache-Control</param-name> <param-value>max-age=604800, public</param-value> </init-param> </filter> <filter-mapping> <filter-name>CacheForWeek</filter-name> <url-pattern>/js/</url-pattern> </filter-mapping> <filter-mapping> <filter-name>CacheForWeek</filter-name> <url-pattern>/images/</url-pattern> </filter-mapping> <filter-mapping> <filter-name>CacheForWeek</filter-name> <url-pattern>/css/</url-pattern> </filter-mapping>完成这一步,在服务端已经实现了对页面的缓存,但是当前情况下页面还是会每次访问服务器的,只是压力减小了
如何让页面在一段时间内不访问服务器呢
实现方式是对应公用的JS都放到一个页面中,别的页面包含他,在这个页面中增加页面缓存
<meta charset="utf-8"><span style="color:#ff0000;"><meta http-equiv="cache-control" content="max-age=604800, public"></span><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><!--IE10--><meta http-equiv="X-UA-Compatible" content="IE=EmulateIE8"><!--<meta name=”renderer” content=”webkit|ie-comp|ie-stand”>--><meta name="”renderer”" content="”webkit|ie-comp|ie-stand”"><!-- CSS styles --><link rel="stylesheet" type="text/css" href="%24%7BpageContext.request.contextPath%7D/css/base.css"><script src="%24%7BpageContext.request.contextPath%7D/common/jquery/js/jquery-1.8.2.js" charset="utf-8"></script><script src="%24%7BpageContext.request.contextPath%7D/common/jquery/js/jquery.ui.core.js" charset="utf-8"></script>