自定义过滤器

package com.ssm.student.filter;import java.io.IOException;
import java.io.PrintWriter;import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;import org.springframework.web.filter.OncePerRequestFilter;/*** @className SessionFilter* @deprecated 登录过滤器* @author pengfei.xiong* @date 2017年10月8日*/
public class SessionFilter extends OncePerRequestFilter{/** (non-Javadoc)* * @see* org.springframework.web.filter.OncePerRequestFilter#doFilterInternal(* javax.servlet.http.HttpServletRequest,* javax.servlet.http.HttpServletResponse, javax.servlet.FilterChain)*/@Overrideprotected void doFilterInternal(HttpServletRequest request,HttpServletResponse response, FilterChain filterChain)throws ServletException, IOException {//request.getSession().setAttribute("loginedUser", "ssss");// 不过滤的uriString[] notFilter = new String[] { "login.jsp", "index.jsp" };// 请求的uriString uri = request.getRequestURI();// uri中包含background时才进行过滤if (uri.indexOf("do") != -1) {// 是否过滤boolean doFilter = true;for (String s : notFilter) {if (uri.indexOf(s) != -1) {// 如果uri中包含不过滤的uri，则不进行过滤doFilter = false;break;}}if (doFilter) {// 执行过滤// 从session中获取登录者实体Object obj = request.getSession().getAttribute("loginedUser");if (null == obj) {// 如果session中不存在登录者实体，则弹出框提示重新登录// 设置request和response的字符集，防止乱码request.setCharacterEncoding("UTF-8");response.setCharacterEncoding("UTF-8");response.setContentType("text/html");PrintWriter out = response.getWriter();String loginPage = "login-old.jsp";StringBuilder builder = new StringBuilder();builder.append("<script type=\"text/javascript\">");builder.append("alert('网页过期，请重新登录');");builder.append("window.top.location.href='");builder.append(loginPage);builder.append("';");builder.append("</script>");out.print(builder.toString());} else {// 如果session中存在登录者实体，则继续filterChain.doFilter(request, response);}} else {// 如果不执行过滤，则继续filterChain.doFilter(request, response);}} else {// 如果uri中不包含background，则继续filterChain.doFilter(request, response);}}//在web.xml中配置..
}

web.xml配置过滤器

<!-- 自定义过滤器 --><filter><filter-name>sessionFilter</filter-name><filter-class>com.ssm.student.filter.SessionFilter</filter-class></filter><filter-mapping><filter-name>sessionFilter</filter-name><url-pattern>/*</url-pattern></filter-mapping>