如何将 HttpRequest 复制到另一个 Web 服务？

Question

我当前在同一台 PC 上安装了两个相同的 Web 服务用于测试目的。第一个服务收到的请求也应该发送到第二个服务。我的目的是使用 HttpModule 来做到这一点。我在 application.BeginRequest 期间处理请求。

public void AsyncForwardRequest(HttpRequest request)
{
    try
    {
        // Prepare web request...
        HttpWebRequest req = (HttpWebRequest)WebRequest.Create(WSaddress);

        req.Credentials = CredentialCache.DefaultCredentials;
        req.Headers.Add("SOAPAction", request.Headers["SOAPAction"]);
        req.ContentType = request.Headers["Content-Type"];
        req.Accept = request.Headers["Accept"];
        req.Method = request.HttpMethod;

        // Send the data.
        long posStream = request.InputStream.Position;
        long len = request.InputStream.Length;
        byte[] buff = new byte[len];
        request.InputStream.Seek(0, SeekOrigin.Begin);
        if (len < int.MaxValue && request.InputStream.Read(buff, 0, (int)len) > 0)
        {
            using (Stream stm = req.GetRequestStream())
            {
                stm.Write(buff, 0, (int)len);
            }

            request.InputStream.Position = posStream;
            DebugOutputStream(request.InputStream);
            request.InputStream.Seek(0, SeekOrigin.Begin);

            IAsyncResult result = (IAsyncResult)req.BeginGetResponse(new AsyncCallback(RespCallback), req);
        }
    }
    catch (Exception ex)
    {

        App.Error2(String.Format("RequestDuplicatorModule - BeginRequest; ERROR begin request: {0}", ex.Message), ex);
    }

private static void RespCallback(IAsyncResult asynchronousResult)
{
    try
    {
        // State of request is asynchronous.
        var req = (HttpWebRequest)asynchronousResult.AsyncState;
        WebResponse resp = (HttpWebResponse)req.EndGetResponse(asynchronousResult);

        Stream responseStream = resp.GetResponseStream();
        System.IO.Stream stream = responseStream;
        Byte[] arr = new Byte[1024 * 100];
        stream.Read(arr, 0, 1024 * 100);
        if (arr.Length > 0)
        {
            string body = (new ASCIIEncoding()).GetString(arr);
            Debug.Print(body);
        }
    }
    catch (WebException ex)
    {
        App.Error2(String.Format("RequestDuplicatorModule - BeginRequest; ERROR begin request: {0}", ex.Message), ex);
    }

}

此 (HttpWebResponse)req.EndGetResponse(asynchronousResult) 引发异常：500 内部服务器错误并失败。原来的请求进展顺利。

请求.InnerStream： ...

这与网络服务地址不同有什么关系吗？就我而言，他们是： http://localhost/WS/service.asmx http://localhost/WS_replicate/service.asmx

Answer 1

我至少会实现这个，以便能够读取状态为 500 的 httpwebrequest 的内容：

catch (WebException ex)
{
    HttpWebResponse webResponse = (HttpWebResponse)ex.Response;
    Stream dataStream = webResponse.GetResponseStream();

    if (dataStream != null)
    {
        StreamReader reader = new StreamReader(dataStream);
        response = reader.ReadToEnd();
    }
}

虽然没有回答您的问题，但我建议使用一个简单的 amsx 来读取请求，并将请求发布到两个不同的网络服务。如果您需要一些代码，请告诉我。

其他优点是 asmx 将更容易为开发人员以及处理部署的人员提供支持。您可以添加配置选项以使实际 url 动态化。

Answer 2

能够修改 AsyncForwardRequest 方法，以便我可以实际编辑 SoapEnvelope 本身：

string buffString = System.Text.UTF8Encoding.UTF8.GetString(buff);

using (Stream stm = req.GetRequestStream())
{
    bool stmIsReadable = stm.CanRead;  //false, stream is not readable, how to get
                                       //around this?
                                       //solution: read Byte Array into a String,
                                       //modify <wsa:to>, write String back into a
                                       //Buffer, write Buffer to Stream

    buffString = buffString.Replace("http://localhost/WS/Service.asmx", WSaddress);

    //write modded string to buff
    buff = System.Text.UTF8Encoding.UTF8.GetBytes(buffString);

    stm.Write(buff, 0, (int)buff.Length);
}