java中filter的用法.docxVIP

??filter过滤器主要使用于前台向后台传递数据是的过滤操作。程度很简单就不说明了，直接给几个已经写好的代码：一、使浏览器不缓存页面的过滤器 Java代码 ?import javax.servlet.*;import javax.servlet.http.HttpServletResponse;import java.io.IOException;/**?* 用于的使 Browser 不缓存页面的过滤器?*/public class ForceNoCacheFilter implements Filter {public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain) throws IOException, ServletException?{ ((HttpServletResponse) response).setHeader(Cache-Control,no-cache); ((HttpServletResponse) response).setHeader(Pragma,no-cache); ((HttpServletResponse) response).setDateHeader (Expires, -1); filterChain.doFilter(request, response);?}?public void destroy()?{?}?public void init(FilterConfig filterConfig) throws ServletException?{?}}二、检测用户是否登陆的过滤器?import?javax.servlet.*;import?javax.servlet.http.HttpServletRequest;? import?javax.servlet.http.HttpServletResponse; ? import?javax.servlet.http.HttpSession; ? import?java.util.List; ? import?java.util.ArrayList; ? import?java.util.StringTokenizer; ? import?java.io.IOException; ? ? ? /**??*?用于检测用户是否登陆的过滤器，如果未登录，则重定向到指的登录页面p ? ??*?配置参数p ? ??*?checkSessionKey?需检查的在?Session?中保存的关键字br/ ? ??*?redirectURL?如果用户未登录，则重定向到指定的页面，URL不包括?ContextPathbr/ ? ??*?notCheckURLList?不做检查的URL列表，以分号分开，并且?URL?中不包括?ContextPathbr/ ? ??*/? ? public?class?CheckLoginFilter ? ?implements?Filter ? { ? ?protected?FilterConfig?filterConfig?=?null; ? ?private?String?redirectURL?=?null; ? ?private?List?notCheckURLList?=?new?ArrayList(); ? ?private?String?sessionKey?=?null; ? ? ? ?public?void?doFilter(ServletRequest?servletRequest,?ServletResponse?servletResponse,?FilterChain?filterChain)?throws?IOException,?ServletException ? ?{ ? ?HttpServletRequest?request?=?(HttpServletRequest)?servletRequest; ? ?HttpServletResponse?response?=?(HttpServletResponse)?servletResponse; ? ? ? ?HttpSession?session?=?request.getSession(); ? ?if(sessionKey?==?null) ? ?{ ? ?filterChain.doFilter(request,?response); ? ?return; ? ?} ? ?if((!checkRequestURIIntNotFilterList(request))??session.getAttribu