全局拦截ajax异常

$.ajaxSetup({
    contentType:"application/x-www-form-urlencoded;charset=utf-8",
    complete:function(XMLHttpRequest,textStatus){
    },
    statusCode: {
        401: function() {
            alert('登录失效，请重新登录');
            window.location.href = "wechatLogin.html";
        }
    }
});