5个有用过滤器 filter

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1、5个有用的过滤器Filter/**一、使浏览器不缓存页面的过滤器*用于的使Browser不缓存页面的过滤器*/importjavax.servlet.*;importjavax.servlet.http.HttpServletResponse;importjava.io.IOException;publicclassForceNoCacheFilterimplementsFilter{publicvoiddoFilter(ServletRequestrequest,ServletResponseresponse,

2、FilterChainfilterChain)throwsIOException,ServletException{((HttpServletResponse)response).setHeader("Cache-Control","no-cache");((HttpServletResponse)response).setHeader("Pragma","no-cache");((HttpServletResponse)response).setDateHeader("Expires",-1);filterCh

3、ain.doFilter(request,response);}publicvoiddestroy(){}publicvoidinit(FilterConfigfilterConfig)throwsServletException{}}/**二、检测用户是否登陆的过滤器*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*配置参数*checkSessionKey需检查的在Session中保存的关键字*redirectURL如果用户未登录，则重定向到指定的页面，URL不包括ContextPath*no

4、tCheckURLList不做检查的URL列表，以分号分开，并且URL中不包括ContextPath*/importjavax.servlet.*;importjavax.servlet.http.HttpServletRequest;importjavax.servlet.http.HttpServletResponse;importjavax.servlet.http.HttpSession;importjava.util.List;importjava.util.ArrayList;importjava.u

5、til.StringTokenizer;importjava.io.IOException;publicclassCheckLoginFilterimplementsFilter{protectedFilterConfigfilterConfig=null;privateStringredirectURL=null;privateListnotCheckURLList=newArrayList();privateStringsessionKey=null;publicvoiddoFilter(ServletReq

6、uestservletRequest,ServletResponseservletResponse,FilterChainfilterChain)throwsIOException,ServletException{HttpServletRequestrequest=(HttpServletRequest)servletRequest;HttpServletResponseresponse=(HttpServletResponse)servletResponse;HttpSessionsession=reques

7、t.getSession();if(sessionKey==null){filterChain.doFilter(request,response);return;}if((!checkRequestURIIntNotFilterList(request))&&session.getAttribute(sessionKey)==null){response.sendRedirect(request.getContextPath()+redirectURL);return;}filterChain.doFilter

8、(servletRequest,servletResponse);}publicvoiddestroy(){notCheckURLList.clear();}privatebooleancheckRequestURIIntNotFilterList(HttpServletRequestrequest){Stringuri=request.getServletPath()+