I'd like to send a picture from my Windows Phone on a webservice hosted on Windows Azure.
To communicate with my service, I use RESTSharp and I saw that there was a method named addFile for sending file.
RestRequest request;
request = new RestRequest("/report/add", Method.POST);
request.AddFile("test", ConvertToBytes(e.ChosenPhoto), "testfile");
App.Client.ExecuteAsync(request, response =>
{
RestResponse resource = response;
if (response.StatusCode == HttpStatusCode.OK)
{
MessageBox.Show("Your report has been sent! Thank you for your participation!");
}
});
However, I do not know how to retrieve the array of bytes sent when the request arrives at the service.
Can you help me please?
Could you show the code that you use to handle the file server side? It could be that you're looking in the wrong place.
Alternatively, you could try an other way to add the file:
request.AddBody(new { myFile = fileByteArray }))
Note: In both cases the file will be loaded in memory. This could be a problem for large files.
Related
Under Asp.Net MVC I used to build the body of my mailing messages on a MVC view which the system downloaded through System.Net.HttpWebRequest.
Now that I am migrating to Blazor server, I can browse the page but if I try to download it to fill the body of the message I always get next body:
Loading... An unhandled exception has occurred. See browser dev
tools for details. Reload X
I tried both through a Blazor page and through a Cshtml razor page. My browser can see both successfully but I always get the same exception.
This is the code I use to download the page:
HttpResponseMessage response = await http.GetAsync(url);
if (response.IsSuccessStatusCode)
{
var contentType = response.Content?.Headers?.ContentType?.MediaType;
if (contentType == "application/json" | contentType == "text/html")
{
string responseText = await response.Content?.ReadAsStringAsync() ?? "";
if (typeof(T) == typeof(string))
retval.Value = (T)(object)responseText;
else
retval.Value = Newtonsoft.Json.JsonConvert.DeserializeObject<T>(responseText);
}
else
{
byte[] result = await response.Content.ReadAsByteArrayAsync();
retval.Value = (T)Convert.ChangeType(result, typeof(T));
}
}
}
I finally discovered the problem was on Program.cs from my .Net7 Server side Blazor app.
I was registering HttpClient as follows:
var http = new HttpClient();
builder.Services.AddScoped(sp => http);
This was Ok to access API data, but for some reason if you try to download a Html page source it throws a System.ObjectDisposedException: Cannot access a disposed object.
The right way to register the service to avoid this exception is:
builder.Services.AddHttpClient();
The problem is I no longer have a http variable in Program.cs, which I used to preload data from Api before the index page was ready.
Need a bit more detail:
What line threw the exception?
What was the exception?
What was value of string responseText or byte[] result?
I suspect either the DeserializeObject or Convert.ChangeType call failed. You should debug this; the answer will probably become apparent as you step through the code.
I have a legacy system interfacing issue that my team has elected to solve by standing up a .NET 7 Minimal API which needs to accept a file upload. It should work for small and large files (let's say at least 500 MiB). The API will be called from a legacy system using HttpClient in a .NET Framework 4.7.1 app.
I can't quite seem to figure out how to design the signature of the Minimal API and how to call it with HttpClient in a way that totally works. It's something I've been hacking at on and off for several days, and haven't documented all of my approaches, but suffice it to say there have been varying results involving, among other things:
4XX and 500 errors returned by the HTTP call
An assortment of exceptions on either side
Calls that throw and never hit a breakpoint on the API side
Calls that get through but the Stream on the API end is not what I expect
Errors being different depending on whether the file being uploaded is small or large
Text files being persisted on the server that contain some of the HTTP headers in addition to their original contents
On the Minimal API side, I've tried all sorts of things in the signature (IFormFile, Stream, PipeReader, HttpRequest). On the calling side, I've tried several approaches (messing with headers, using the Flurl library, various content encodings and MIME types, multipart, etc).
This seems like it should be dead simple, so I'm trying to wipe the slate clean here, start with an example of something that partially works, and hope someone might be able to illuminate the path forward for me.
Example of Minimal API:
// IDocumentStorageManager is an injected dependency that takes an int and a Stream and returns a string of the newly uploaded file's URI
app.MapPost(
"DocumentStorage/CreateDocument2/{documentId:int}",
async (PipeReader pipeReader, int documentId, IDocumentStorageManager documentStorageManager) =>
{
using var ms = new MemoryStream();
await pipeReader.CopyToAsync(ms);
ms.Position = 0;
return await documentStorageManager.CreateDocument(documentId, ms);
});
Call the Minimal API using HttpClient:
// filePath is the path on local disk, uri is the Minimal API's URI
private static async Task<string> UploadWithHttpClient2(string filePath, string uri)
{
var fileStream = File.Open(filePath, FileMode.Open);
var content = new StreamContent(fileStream);
var httpRequestMessage = new HttpRequestMessage(HttpMethod.Post, uri);
var httpClient = new HttpClient();
httpRequestMessage.Content = content;
httpClient.Timeout = TimeSpan.FromMinutes(5);
var result = await httpClient.SendAsync(httpRequestMessage);
return await result.Content.ReadAsStringAsync();
}
In the particular example above, a small (6 bytes) .txt file is uploaded without issue. However, a large (619 MiB) .tif file runs into problems on the call to httpClient.SendAsync which results in the following set of nested Exceptions:
System.Net.Http.HttpRequestException - "Error while copying content to a stream."
System.IO.IOException - "Unable to write data to the transport connection: An existing connection was forcibly closed by the remote host.."
System.Net.Sockets.SocketException - "An existing connection was forcibly closed by the remote host."
What's a decent way of writing a Minimal API and calling it with HttpClient that will work for small and large files?
Kestrel allows uploading 30MB per default.
To upload larger files via kestrel you might need to increase the max size limit. This can be done by adding the "RequestSizeLimit" attribute. So for example for 1GB:
app.MapPost(
"DocumentStorage/CreateDocument2/{documentId:int}",
[RequestSizeLimit(1_000_000_000)] async (PipeReader pipeReader, int documentId) =>
{
using var ms = new MemoryStream();
await pipeReader.CopyToAsync(ms);
ms.Position = 0;
return "";
});
You can also remove the size limit globally by setting
builder.WebHost.UseKestrel(o => o.Limits.MaxRequestBodySize = null);
This answer is good but the RequestSizeLimit filter doesn't work for minimal APIs, it's an MVC filter. You can use the IHttpMaxRequestBodySizeFeature to limit the size (assuming you're not running on IIS). Also, I made a change to accept the body as a Stream. This avoids the memory stream copy before calling the CreateDocument API:
app.MapPost(
"DocumentStorage/CreateDocument2/{documentId:int}",
async (Stream stream, int documentId, IDocumentStorageManager documentStorageManager) =>
{
return await documentStorageManager.CreateDocument(documentId, stream);
})
.AddEndpointFilter((context, next) =>
{
const int MaxBytes = 1024 * 1024 * 1024;
var maxRequestBodySizeFeature = context.HttpContext.Features.Get<IHttpMaxRequestBodySizeFeature>();
if (maxRequestBodySizeFeature is not null and { IsReadOnly: true })
{
maxRequestBodySizeFeature.MaxRequestBodySize = MaxBytes;
}
return next(context);
});
If you're running on IIS then https://learn.microsoft.com/en-us/iis/configuration/system.webserver/security/requestfiltering/requestlimits/#configuration
As there are no API for this I need to get the HTML of the following website with WebClient response method.
HttpClient client = new HttpClient();
try
{
HttpResponseMessage response = await client.GetAsync("https://www.datawrapper.de/_/UPFwh/");
response.EnsureSuccessStatusCode();
string responseBody = await response.Content.ReadAsStringAsync();
}
catch(HttpRequestException e)
{
}
client.Dispose(true);
The problem is, when I do that I get only the source code of normal javascripts of this single page application and not the real HTML.
Anybody know how to grab the real html with
I profiled the traffic a bit and it looks like the response from that URL you're using is indeed mainly a script, which eventually will load the rest of the website.
Looking through the details the HTML part of the main data seems to be available under a different URL:
https://datawrapper.dwcdn.net/UPFwh/34/
Consider using that instead. Hope this helps!
The title basically explains itself.
I have a REST endpoint with VertX. Upon hitting it, I have some logic which results in an AWS-S3 object.
My previous logic was not to upload to S3, but to save it locally. So, I can do this at the response routerCxt.response().sendFile(file_path...).
Now that the file is in S3, I have to download it locally before I could call the above code.
That is slow and inefficient. I would like to stream S3 object directly to the response object.
In Express, it's something like this. s3.getObject(params).createReadStream().pipe(res);.
I read a little bit, and saw that VertX has a class called Pump. But it is used by vertx.fileSystem() in the examples.
I am not sure how to plug the InputStream from S3'sgetObjectContent() to the vertx.fileSystem() to use Pump.
I am not even sure Pump is the correct way because I tried to use Pump to return a local file, and it didn't work.
router.get("/api/test_download").handler(rc -> {
rc.response().setChunked(true).endHandler(endHandlr -> rc.response().end());
vertx.fileSystem().open("/Users/EmptyFiles/empty.json", new OpenOptions(), ares -> {
AsyncFile file = ares.result();
Pump pump = Pump.pump(file, rc.response());
pump.start();
});
});
Is there any example for me to do that?
Thanks
It can be done if you use the Vert.x WebClient to communicate with S3 instead of the Amazon Java Client.
The WebClient can pipe the content to the HTTP server response:
webClient = WebClient.create(vertx, new WebClientOptions().setDefaultHost("s3-us-west-2.amazonaws.com"));
router.get("/api/test_download").handler(rc -> {
HttpServerResponse response = rc.response();
response.setChunked(true);
webClient.get("/my_bucket/test_download")
.as(BodyCodec.pipe(response))
.send(ar -> {
if (ar.failed()) {
rc.fail(ar.cause());
} else {
// Nothing to do the content has been sent to the client and response.end() called
}
});
});
The trick is to use the pipe body codec.
I am using System.Net.Http.HttpClient to post a sequence of requests from a console application to a REST API and to deserialize the JSON responses into strongly-typed objects. My implementation is like this:
using (var client = new HttpClient())
{
var content = new StringContent(data, Encoding.UTF8, "text/html");
var response = client.PostAsync(url, content).Result;
response.EnsureSuccessStatusCode();
return response.Content.ReadAsAsync<MyClass>().Result;
}
However, I am experiencing a problem very similar to one described in this question, whereby everything works fine when the requests are routed via Fiddler, but it hangs after the 4th or 5th request when Fiddler is disabled.
If the cause of the problem is the same, I assume I need to do something more with HttpClient to get it to fully release its resources after each request but I am unable to find any code samples that show how to do this.
Hoping somebody can point me in the right direction.
Many thanks,
Tim
You are not disposing of the HttpResponseMessage object. This can leave open streams with the server, and after some quota of streams with an individual server is filled, no more requests will be sent.
using (var client = new HttpClient())
{
var content = new StringContent(data, Encoding.UTF8, "text/html");
using(var response = client.PostAsync(url, content).Result)
{
response.EnsureSuccessStatusCode();
return response.Content.ReadAsAsync<MyClass>().Result;
}
}