Filter设置缓存

publicclass JspFilterimplements Filter {

    publicvoid destroy() {

    }

    publicvoid doFilter(ServletRequest request, ServletResponseresponse, FilterChain chain)throws IOException, ServletException {

       //设置对jsp页不保存

       HttpServletResponse resp = (HttpServletResponse) response;

       resp.setHeader("expires","-1");

       resp.setHeader("cache-control","no-cache");

       resp.setHeader("pragam","no-cache");

       chain.doFilter(request, response);

    }

    publicvoid init(FilterConfig fConfig)throws ServletException {

    }

}

 

<filter>

   <display-name>JspFilter</display-name>

   <filter-name>JspFilter</filter-name>

   <filter-class>czb.filter.JspFilter</filter-class>

 </filter>

 <filter-mapping>

   <filter-name>JspFilter</filter-name>

   <url-pattern>*.jsp</url-pattern>

  </filter-mapping>

以下是设置保存多长时间：

    publicvoid doFilter(ServletRequest request, ServletResponseresponse,

           FilterChain chain) throws IOException, ServletException{

 

       HttpServletResponse resp = (HttpServletResponse) response;

       Calendar cal = Calendar.getInstance();

       //加7天

       cal.add(Calendar.DATE, 7);

       long time = cal.getTimeInMillis();

       resp.setDateHeader("expires", time);

       chain.doFilter(request, response);

    }

<filter>

   <display-name>PictureFilter</display-name>

   <filter-name>PictureFilter</filter-name>

   <filter-class>czb.filter.PictureFilter</filter-class>

 </filter>

 <filter-mapping>

   <filter-name>PictureFilter</filter-name>

   <url-pattern>*.jpg</url-pattern>

  </filter-mapping>