I am using the Flurl framework to call web service methods.
One of this method returns a file content as a Stream using FileStreamActionResult as a return value of my web service.
On the client side I am using the DownloadFileAsync extension method implemented in Flurl.
All is working good..
Now in case of very big file, I want the process to be able to resume at a point where the download could have been stopped (because loose of network...or even because the user has closed the app).
Is this possible with Flurl ?
Regards.
No, Flurl doesn't provide that functionality.
Related
I encoutered a question here and need your help.
I had a .net web api project using PushStream to do async downloading, something like
new PushStreamContent(async (outputStream, httpContent, transportContext))=>{}
In this way, I can do multiple parts downloading in the action.
However, now I want to move the project into .net core and I cannot find a replacement in .net core for pushstream.
Could you please let me know is there something like pushstream in .net core or any methods to implement it?
Thanks a lot.
PushStreamContent works by essentially setting a callback to be invoked when the output stream is being processed. This was necessary in ASP.NET Web Api because there was no direct access to OutputStream.
However, in ASP.NET Core, you do have direct access to the output stream via HttpContext.Response.Body. As a result, you can just directly write to that stream without needing something like PushStreamContent.
FWIW, while this can save some server resources, it's actually pretty bad, especially with something like an API. Since you're writing directly to the output stream, the headers are already sent, including the response status code. This means if there's any exception raised while you're writing, there's no opportunity to handle it appropriately. The response is simply aborted, and the client is left hanging with a supposedly "successful" response, and only a partial body. Personally, I would say avoid this practice altogether and take the resource hit. Unless you're streaming gigs of data, any good server setup will have a plentiful amount of RAM to handle what you're doing. Even then, there's probably better methods to handle delivering that data.
I have develope a small web application in that i am using wcf service,I have creating a methods like GetData(), When i call this method in Browser it doesn't show any data just it showing blank page please help me how can i resolve this problem.
http://localhost:54421/Service1.svc/GetData
Contrary to SOAP ASMX web services with WCF you can no longer invoke them directly in the browser. You could use the WcfTestClient.exe utility to quickly test a method. You can invoke the method directly in the browser if you are using REST and GET verb is allowed for this method.
What does this mean? google search turns up nothing.
The curious thing is that I get this message when I try to access the web service directly in the browser http://localhost/Myservice/Service.asmx
But when I use the service (I invoke it inside my Jquery code) it works perfectly. Very curious detail....
This might be because you have a function in your web service that returns an interface, or that returns an object that contains a property or function using an interface. For further details on interfaces and serialization take a look at this SO question.When you use your web service from javascript you only call one or more specific functions, but browsing on your web service with internet explorer forces a request of a whole wsdl description of your the web service with all its functions. I guess that is why it worked for the first case and not for the second.
I would like to pass an arrayList of objects to a servlet from a java program.
Can some one please tell me, how this can be done.
Look at this link they describe the process ind detail
http://www2.sys-con.com/ITSG/virtualcd/java/archives/0309/darby/index.html
Please note that if you are going to serialize objects back and forth that the compiled version must be in sync on both the client and the server or you will get errors. I would recommend converting your objects to either XML or JSON and then reading them from that on the server side. That way if you client and server code get out of sync it will still work.
For the client I would recommend Apache's HttpClient (or whatever they have renamed it to)
Have you considered using a web service framework for this instead of coding a naked servlet? The whole business might be about 10 lines of code using, for example, an Apache CXF JAX-RS service and client. If the objects are complex, you might want to use a full SOAP service.
Other than using a web service, is there anyway to call a method in a web app from a windows application? Both run on the same machine.
I basically want to schedule a job to run a windows app which updates some file (for a bayesian spam filter), then I want to notify the web app to reload that file.
I know this can be done in other ways but I'm curious to know whether it's possible anyway.
You can make your windows app connect to the web app and do a GET in a page that responds by reloading your file, I don't think it is strictly necessary to use a web service. This way you can also make it happen from a web browser.
A Web Service is the "right" way if you want them to communicate directly. However, I've found it easier in some situations to coordinate via database records. For example, my web app has bulk email capability. To make it work, the web app just leaves a database record behind specifying the email to be sent. The WinApp scans periodically for these records and, when it finds one with an "unprocessed" status, it takes the appropriate action. This works like a charm for me in a very high volume environment.
You cannot quite do this in the other direction only because web apps don't generally sit around in a timing loop (there are ways around this but they aren't worth the effort). Thus, you'll require some type of initiating action to let the web app know when to reload the file. To do this, you could use the following code to do a GET on a page:
WebRequest wrContent = WebRequest.Create("http://www.yourUrl.com/yourpage.aspx");
Stream objStream = wrContent.GetResponse().GetResponseStream();
// I don't think you'll need the stream Reader but I include it for completeness
StreamReader objStreamReader = new StreamReader(objStream);
You'll then reload the file in the PageLoad method whenever this page is opened.
How is the web application loading the file? If you were using a dependency on the Cache object, then simply updating the file will invalidate the Cache entry, causing your code to reload that entry when it is found to be null (or based on the "invalidated" event).
Otherwise, I don't know how you would notify the application to update the file.
An ASP.NET application only exists as an instance to serve a request. This is why web services are an easy way to handle this - the application has been instantiated to serve the service request. If you could be sure the instance existed and got a handle to it, you could use remoting. But without having a concrete handle to an instance of the application, you can't invoke the method directly.
There's plenty of other ways to communicate. You could use a database or some other kind of list which both applications poll and update periodically. There are plenty of asynchronous MQ solutions out there.
So you'll create a page in your webapp specifically for this purpose. Use a Get request and pass in a url parameter. Then in the page_load event check for this paremter. if it exists then do your processing. By passing in the parameter you'll prevent accidental page loads that will cause the file to be uploaded and processed when you don't want it to be.
From the windows app make the url Get request by using the .Net HttpWebRequest. Example here: http://www.codeproject.com/KB/webservices/HttpWebRequest_Response.aspx