Jquery ajax捕获错误信息

$.ajax({
            type: "POST",//方法类型
            dataType: "json",//预期服务器返回的数据类型
            url: requestUrl,//url
            data: ajaxParams,
            async: async,
            success: function (result) {
                if (result.success == "true") {
                    if (result.message != undefined) {
                        $.showSuccessToast(result.message);
                    }
                    if (typeof (callBackFunction) == 'function')
                        if (result.data == undefined) {
                            callBackFunction()
                        } else {
                            callBackFunction(result.data)
                        }
                } else {
                    $.showErrorToast(result.message);
                }
            },
            error: function (req, status, error) {
                console.log(req);
                console.log(status);
                $.showErrorToast("连接服务器失败！错误信息：" + error);
            }
        });