session过期情况下ajax请求不会触发重新登录的问题

String requestType = request.getHeader("X-Requested-With"); ???????????if (!StringUtils.isEmpty(requestType) && requestType.equalsIgnoreCase("XMLHttpRequest")) { ???????????????response.setHeader("sessionStatus", "timeout"); ???????????????response.sendError(518, "session timeout."); ???????????}

//定义ajax全局事件$(document).ajaxError(function(jqxhr, error) { ???var sessionStatus = error.getResponseHeader("sessionStatus"); ???if (sessionStatus == "timeout") { ???????$.MsgBox.Alert("系统提示", "您的登录信息已过期，请重新登录！", function(){ ???????????top.location.href = "${pageContext.request.contextPath}"; ???????}) ???} ???var operationStatus = error.getResponseHeader("operationStatus"); ???if (operationStatus == "refused") { ???????$.MsgBox.Alert("系统提示", "您没有权限执行该操作！", function(){ ???????????top.location.href = contextPath; ???????}) ???}});