设置ajaxError
通过设置ajaxError ajaxComplete可以或者ajax 异常

$(document).ajaxError(function(event, jqxhr, settings, exception) {window.console && console.log(exception);alert('An unexpected error has occurred. Please contact support.\nError requesting page ' + settings.url);});$(document).ajaxComplete(function(event, xhr, settings) {if (xhr.responseText == "AJAX_UNEXPECTED_EXCEPTION") {alert('An error has occurred. Please contact support.');}});