1、判断普通请求还是ajax请求分别跳转

if(isAjaxRequest){//是ajax请求
					PrintWriter wirter =  response.getWriter();
				    wirter.write("timeout");
				    wirter.flush();
				} else {//非ajax请求直接跳转
					response.sendRedirect(loginUrl + "?service=" + service);
				}

2、ajax请求超时处理

$.ajaxSetup({
	global: false,type: "POST",complete: function (XMLHttpRequest,textStatus) {
		var data = XMLHttpRequest.responseText;
		if (data == "timeout") {
			//if( window.top != window.self ){
				// window.top.location = "${pageContext.request.contextPath}";
				alert('请重新登录!');
			//}
		}
	}
});