JS全局添加token

var token = sessionStorage.getItem("UserTocken");
if(token){
    $.ajaxSetup({ //发送请求前触发
               beforeSend: function(xhr) { //可以设置自定义标头
                     xhr.setRequestHeader('Authorization', "Bearer " + token);
               }
    })
}else{
    var host_url = window.location.host;
    window.location.replace("http://" + host_url);
}