JSP/HTML页面（公共JS、CSS、Image缓存）-----静态缓存

r囧r小猫 2023-10-17 09:32 127阅读 0赞

【1】服务端配置一个Filter，实现对js、css和image的缓存

package com.cache.model.filter;
    
    import java.io.IOException;
    import java.util.Enumeration;
    
    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.HttpServletResponse;
    
    public class CacheFilter implements Filter {
    	private FilterConfig fc;  
    	
    	@Override
    	public void destroy() {
    		// TODO Auto-generated method stub
    		this.fc = null;
    	}
    
    	@Override
    	public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
    			throws IOException, ServletException {
    		// TODO Auto-generated method stub
    		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);  
    	}
    
    	@Override
    	public void init(FilterConfig filterConfig) throws ServletException {
    		// TODO Auto-generated method stub
    		 this.fc = filterConfig;  
    	}
    
    }

web.xml配置

<?xml version="1.0" encoding="UTF-8"?>
    <web-app version="2.5" 
    	xmlns="http://java.sun.com/xml/ns/javaee" 
    	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
    	http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
      
      <filter>  
            <filter-name>CacheFilter</filter-name>  
            <filter-class>com.cache.model.filter.CacheFilter</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>CacheFilter</filter-name>  
            <url-pattern>/js/*</url-pattern>  
        </filter-mapping>  
        <filter-mapping>  
            <filter-name>CacheFilter</filter-name>  
            <url-pattern>/images/*</url-pattern>  
        </filter-mapping>  
        <filter-mapping>  
            <filter-name>CacheFilter</filter-name>  
            <url-pattern>/css/*</url-pattern>  
        </filter-mapping> 
    
      
    
    </web-app>

完成这一步，在服务端已经实现了对页面公共资源的缓存，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。

如何让页面公共资源在用户第一次加载后，就不需要服务器二次加载？

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（特定静态资源）

<%@ page language="java" pageEncoding="utf-8"%>
    <%
    String path = request.getContextPath();
    String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
    %>
    <meta charset="utf-8" />
    <meta http-equiv="cache-control" content="max-age=604800, public"/>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    
    <meta http-equiv="X-UA-Compatible" content="IE=EmulateIE8" />
    
    <meta name=”renderer” content=”webkit|ie-comp|ie-stand” />
    
    <link rel="stylesheet" type="text/css" href="<%=basePath%>commons/css/bootstrap.min.css" />
    <script src="<%=basePath%>commons/js/jquery-1.4.2.min.js" charset="utf-8"></script>

页面应用：

<%@ page language="java" pageEncoding="utf-8"%>
    <%
    String path = request.getContextPath();
    String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
    %>
    <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
    <head>
     <jsp:include page="index.jsp" flush="true"/>  
    <title>页面缓存</title>
    </head>
    <body>
    
    </body>
    </html>

google 浏览器分析：

![Center][]

[Center]: https://img-blog.csdn.net/20161125104139863?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center