Ajax不支持重定向请求，当session失效后，点击按钮（发生的ajax请求）不会重定向登录页面。但是针对form表单形式的提交，可以通过配置sessionFilter来重定向到登录页面。

SessionFilter配置

import com.google.gson.Gson;
import org.apache.commons.lang3.StringUtils;
import org.apache.log4j.Logger;
import com.entity.User;
import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
 * @about  session过滤器，处理登录拦截
public class SessionFilter implements Filter {
		private static final Logger logger = LoggerFactory.getLogger(SessionFilter.class); 
    	* ajax请求标志
    private static final String XMLHTTPREQUEST = "XMLHttpRequest";
    Gson gson = new Gson();
    FilterConfig config = null;
    //定义需要忽略的请求
    private String[] ignoreArr = null; 
    @Override
    public void destroy() {
        this.config = null;
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse,
                         FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;
        boolean flag = isIgonre(request);
				//需要忽略的请求
        if (flag) {
            filterChain.doFilter(servletRequest, servletResponse);
        } else {
        		//登录页面请求
            String loginUrl = config.getInitParameter("loginAction");
            //获取真实请求地址
            GamsConfig.getConfig().contextPath = request.getContextPath();
						//如果是登录页或者自定义过滤的请求，放行
            if (requestUri.endsWith(loginStr)) {
                filterChain.doFilter(servletRequest, servletResponse);
                return;
						//从session里面获取用户信息
            User user = (User)  request.getSession().getAttribute("user");
            // 请求是否是XMLHttpRequest类型
            String type = request.getHeader("X-Requested-With") == null ? "" : request.getHeader("X-Requested-With");
            if (user == null) {
                if (StringUtils.equals(XMLHTTPREQUEST, type)) {
                    //告诉ajax这是重定向
                    response.setHeader("REDIRECT", "REDIRECT");
                } else {
                    response.setHeader("SESSIONSTATUS", "TIMEOUT");
                    response.sendRedirect(loginUrl);
                //重定向登录页面地址
                response.setHeader("CONTEXTPATH", loginUrl);
                response.setStatus(HttpServletResponse.SC_FORBIDDEN);
            } else {
                filterChain.doFilter(servletRequest, servletResponse);
     * Tomcat启动时调用，进行初始化
    @Override
    public void init(FilterConfig config) throws ServletException {
        ignoreArr = config.getInitParameter("ignorePattern").split(",");
        this.config = config;
        //initWebSocket();
     * 忽略拦截的部分
    public boolean isIgonre(HttpServletRequest request) {
        String path = request.getRequestURI().toLowerCase();
        for (String ignore : ignoreArr) {
            if (path.contains(ignore)) {
                return true;
        return false;
前端通用JS设置
项目基础js（项目自定的，我这个项目是common.js）中引入该方法：
//解决Ajax请求时无法重定向的问题
$.ajaxSetup( {
    //设置ajax请求结束后的执行动作
    complete : function(XMLHttpRequest, textStatus) {
        // 通过XMLHttpRequest取得响应头，REDIRECT
        var redirect = XMLHttpRequest.getResponseHeader("REDIRECT");
      	//若HEADER中含有REDIRECT说明后端想重定向
        if (redirect === "REDIRECT") {
            var win = window;
            while (win !== win.top){
                win = win.top;
            //将后端重定向的地址取出来,使用win.location.href去实现重定向的要求
            win.location.href= XMLHttpRequest.getResponseHeader("CONTEXTPATH");
web.xml配置
    <!--session-->
    <filter>
        <filter-name>sessionFilter</filter-name>
        <filter-class>com.filter.SessionFilter</filter-class>
        <init-param>
            <param-name>loginAction</param-name>
            <param-value>/heioky/login.action</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>sessionFilter</filter-name>
        <url-pattern>*.action</url-pattern>
    </filter-mapping>
chaohen：www.yuque.com/heioky
搞定~
  
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