常用Serlet过滤器.docVIP

一、字符编码的过滤器 import?javax.servlet.*;import?java.io.IOException; /***?用于设置?HTTP?请求字符编码的过滤器，通过过滤器参数encoding指明使用何种字符编码,用于处理Html?Form请求参数的中文问题*/public?class?CharacterEncodingFilterimplements?Filter{protected?FilterConfig?filterConfig?=?null;protected?String?encoding?=?”; public?void?doFilter(ServletRequest?servletRequest,?ServletResponse?servletResponse,?FilterChain?filterChain)?throws?IOException,?ServletException{if(encoding?!=?null)servletRequest.setCharacterEncoding(encoding);filterChain.doFilter(servletRequest,?servletResponse);} public?void?destroy(){filterConfig?=?null;encoding?=?null;} public?void?init(FilterConfig?filterConfig)?throws?ServletException{this.filterConfig?=?filterConfig;this.encoding?=?filterConfig.getInitParameter(“encoding”); }}二、使浏览器不缓存页面的过滤器 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?{}}三、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 *?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 *?notCheckURLList?不做检查的URL列表，以分号分开，并且?URL?中不包括?ContextPath */public?class?CheckLoginFilterimplements?Filter{protecte