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 ForceNoCacheFilterimplements 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{}}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{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.getAttribute(sessionKey) == null){ response.sendRedirect(request.getContextPath() + redirectURL); return;}filterChain.doFilter(servletRequest, servletResponse);}public void destroy(){notCheckURLList.clear();}private boolean checkRequestURIIntNotFilterList(HttpServletRequest request){String uri = request.getServletPath() + (request.getPathInfo() == null ? "" : request.getPathInfo());return notCheckURLList.contains(uri);}public void init(FilterConfig filterConfig) throws ServletException{this.filterConfig = filterConfig;redirectURL = filterConfig.getInitParameter("redirectURL"); sessionKey = filterConfig.getInitParameter("checkSessionKey");String notCheckURLListStr = filterConfig.getInitParameter("notCheckURLList");if(notCheckURLListStr != null){ StringTokenizer st = new StringTokenizer(notCheckURLListStr, ";"); notCheckURLList.clear(); while(st.hasMoreTokens()) { notCheckURLList.add(st.nextToken()); }}}}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");
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