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!');			//}		}	}});