jq ajax 重写

(function ($) {
　　

　　/首先备份下jquery的ajax方法  
    var $oajax = $.ajax;

//重写jquery的ajax方法  
    $.ajax = function (opt) {
        console.log("执行了重写Ajax");//备份opt重载方法
            var fn = {
                error: function(XMLHttpRequest, textStatus, errorThrown) {},
                success: function(data, textStatus) {},
                beforeSend: function(XHR) {},
                complete: function(XHR, TS) {}
            }
            if (opt.error) {
                fn.error = opt.error;
            }
            if (opt.success) {
                fn.success = opt.success;
            }
            if (opt.beforeSend) {
                fn.beforeSend = opt.beforeSend;
            }
            if (opt.complete) {
                fn.complete = opt.complete;
            }//扩展增强处理  
            var oopt = $.extend(opt,
            {
                error: function(XMLHttpRequest, textStatus, errorThrown) {

                    //console.log("出现错误了");
                    //默认处理方法  
                    fn.error(XMLHttpRequest, textStatus, errorThrown);
                },
                success: function(data, textStatus) {
                    //console.log("执行成功了");
                    fn.success(data, textStatus);

                },
                beforeSend: function(XHR) {
                    //console.log("ajax之前就执行了");

                    fn.beforeSend(XHR);
                },
                complete: function(XHR, TS) {
                    //console.log("执行完成");
                    //默认处理方法  
                    fn.complete(XHR, TS);
                }
            });

　　　　　　$oajax(oopt)

    };
})(jQuery);