Question

我收到了客户的请求，要求为WMS服务的流量控制创建服务。这个想法是：

公司从WMS提供商那里购买了一些数据;
公司在其客户之间分享这些数据;
服务应跟踪已消耗的流量和请求量。

所以我需要某种代理将请求传递给目标WMS服务，同时记录传递的流量。

问题是我不知道如何开始以及从哪里开始。我会欣赏任何想法，概念等。

提前致谢！

Answer 1

以下是我如何实现将请求传递给GeoServer WMS服务并返回地图图像的代理。我使用Web API，.NET 4.5。您可以使用日志记录和授权自定义我的示例。

    public async Task<HttpResponseMessage> GetMapAsync()
    {
        HttpClient client = new HttpClient();

        WmsLayer layer = _unitOfWork.LayerRepository.GetById(model.LayerId) as WmsLayer;

        // This is typical WMS request url pointing to server behind the firewall, 
        // something like http://localhost:8081/geoserver/data/wms?service=WMS&version=1.1.0&request=GetMap&layers=data:layer1&styles=&bbox=337098.1084,4972868.3433,368833.6,5014800.3417&width=387&height=512&srs=EPSG:3765&format=image%2Fpng%3B+mode%3D8bit
        string url = layer.GetWmsRequestUrl(layer.Url, model.SRS, model.Width, model.Height, model.BBox);

        // See http://developer.greenbutton.com/downloading-large-files-with-the-net-httpclient/
        var responseMessage = await client.GetAsync(url, HttpCompletionOption.ResponseHeadersRead);

        var response = Request.CreateResponse();

        response.Content = new PushStreamContent(
            async (outputStream, httpContent, transportContext) =>
            {
                var buffer = new byte[65536];
                using (var httpStream = await responseMessage.Content.ReadAsStreamAsync())
                {
                    var bytesRead = 1;
                    while ((bytesRead = httpStream.Read(buffer, 0, buffer.Length)) > 0)
                    {
                        await outputStream.WriteAsync(buffer, 0, bytesRead);
                    }
                }
                outputStream.Close();
            }
            , new MediaTypeHeaderValue("image/png"));

        return response;
    }

WMS的流量控制

1 个答案: