multipart - Web API マルチパート フォーム データ: 新しい要求が入ったときに生の要求をファイルとして保存できますか?

Question

監査の目的で、新しいリクエストを処理する前に、生のリクエスト (Fiddler に表示される) をファイルとして保存したいと考えています。これはどのように行うことができますか？ありがとう！

Answer 1

Yes, you can do it. Following is an example where I use a message handler to log incoming requests. This handler can be used to log any kind of request(not only the multipartform requests).

//add this handler in your config
config.MessageHandlers.Add(new LoggingMessageHandler());

---

// Logging message handler
public class LoggingMessageHandler : DelegatingHandler
{
    private StringBuilder messageBuilder = null;

    protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
    {
        messageBuilder = new StringBuilder();

        messageBuilder.AppendFormat("{0} {1}", request.Method.Method, request.RequestUri);
        messageBuilder.AppendLine();

        //get request headers information
        GetHeaders(request.Headers);

        //get request content's headers and body
        if (request.Content != null)
        {
            GetHeaders(request.Content.Headers);

            // NOTE 1: 
            // ReadAsStringAsync call buffers the entire request in memory.
            // So, even though you could be consuming the request's stream here, since the entire request is buffered
            // in memory, you can expect the rest of the call stack to work as expected.
            // NOTE 2:
            // Look for performance considerations when the request size is too huge.
            string body = await request.Content.ReadAsStringAsync();

            messageBuilder.AppendLine();
            messageBuilder.Append(body);
        }

        //TODO: log the message here
        //logger.Log(messageBuilder.ToString())

        // call the rest of the stack as usual
        return await base.SendAsync(request, cancellationToken);
    }

    private void GetHeaders(HttpHeaders headers)
    {
        foreach (KeyValuePair<string, IEnumerable<string>> header in headers)
        {
            messageBuilder.AppendLine(string.Format("{0}: {1}", header.Key, string.Join(",", header.Value)));
        }
    }
}