<span style="font-size:24px;">package cn.hncu.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; 
public class CacheFilter implements Filter { 
@Override 
public void destroy() { 
}</span> 
<span style="font-size:24px;"> 
@Override 
public void doFilter(ServletRequest request , ServletResponse response, 
FilterChain chain) throws IOException, ServletException { 
// 過濾器有很多作用，這個(gè)用來設(shè)置客戶端是否設(shè)置緩存的問題,我們這里采用response通知客戶端設(shè)置不緩存 
chain.doFilter(request, response); 
HttpServletResponse res=(HttpServletResponse) response; 
res.setHeader("expries", "-1"); 
res.setHeader("pragma", "no-cache"); 
res.setHeader("cache-control", "no-cache"); 
/*上面的已經(jīng)可以設(shè)置不緩存，但是還可以設(shè)置全面一點(diǎn)： 
//不允許瀏覽器端或緩存服務(wù)器緩存當(dāng)前頁面信息。 
/* response.setHeader( "Pragma", "no-cache" ); 
response.setDateHeader("Expires", "-1"); 
response.addHeader( "Cache-Control", "no-cache" );//瀏覽器和緩存服務(wù)器都不應(yīng)該緩存頁面信息 
response.addHeader( "Cache-Control", "no-store" );//請(qǐng)求和響應(yīng)的信息都不應(yīng)該被存儲(chǔ)在對(duì)方的磁盤 response.addHeader( "Cache-Control", "must-revalidate" );*///于客戶機(jī)的每次請(qǐng)求，代理服務(wù)器必須想服務(wù)器驗(yàn)證緩存是否過時(shí)； 
} 
@Override 
public void init(FilterConfig arg0) throws ServletException { 
} 
}</span><span style="font-size:18px;"> 
</span> 

package cn.hncu.filter; 
import java.io.IOException; 
import java.util.Date; 
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 CacheFilter2 implements Filter { 
@Override 
public void destroy() { 
} 
@Override 
public void doFilter(ServletRequest request , ServletResponse response, 
FilterChain chain) throws IOException, ServletException { 
// 過濾器有很多作用，這個(gè)用來設(shè)置客戶端是否設(shè)置緩存的問題,我們這里采用response通知客戶端設(shè)置緩存 
//這里設(shè)置緩存1天，以實(shí)現(xiàn)讓圖片、視頻類的資源(在過濾器當(dāng)中配置相應(yīng)的攔截路徑)要求客戶瀏覽器緩存1天) 
//攔截路徑在web.xml中配置 
chain.doFilter(request, response);//先進(jìn)行請(qǐng)求，返回也會(huì)從過這里，返回進(jìn)行攔截 
HttpServletResponse res=(HttpServletResponse) response; 
Date d =new Date(); 
Long time=d.getTime()+60*60*24; 
// res.setHeader("expries", ""+time);//這樣就設(shè)置緩存一天 
res.setDateHeader("expries", time);//和上面一句一樣 
/* 
* Date date = new Date(); 
response.setDateHeader("Last-Modified",date.getTime()); //Last-Modified:頁面的最后生成時(shí)間 
response.setDateHeader("Expires",date.getTime()+60*60*24); //Expires:過時(shí)期限值 
response.setHeader("Cache-Control", "public"); //Cache-Control來控制頁面的緩存與否,public:瀏覽器和緩存服務(wù)器都可以緩存頁面信息； 
response.setHeader("Pragma", "Pragma"); //Pragma:設(shè)置頁面是否緩存，為Pragma則緩存，no-cache則不緩存 
*/ 
} 
@Override 
public void init(FilterConfig arg0) throws ServletException { 
}