nginx怎么解决跨域？

$.ajax({

        type:"post",

        dataType: "json",

        data:{'parameter':JSON.stringify(data)},

        url:"/apis/apistest/test",

        async: flag,

        beforeSend: function (xhr) {

            xhr.setRequestHeader("Content-Type", submitType.Content_Type);

            xhr.setRequestHeader("user-id", submitType.user_id);

            xhr.setRequestHeader("role-type", submitType.role_type);

            xhr.setRequestHeader("access-token", getAccessToken().token);

        },

        success:function(result, status, xhr){

        }

        ,error:function (e) {

            layerMsg('请求失败，请稍后再试')

        }

    });